LaPOD: Low cost Logic Analyzer probe for MSO5k, DHO900 and more! - Page 1
Forum section: electronics / testgear

author: oliv3r
author_rank: Frequent Contributor
timestamp: October 06, 2023, 03:38:38 pm
content: After seeing a couple of great pod designs, I decided I wasn't quite happy with the designs overal.What I wanted was to use (mini) HDMI cables, as they are cheap, super common and shielded. Also 4 channels per pod had my preference, to make them nice and small.The design is based on a breakout board, that plugs into the scope, and offers 4 (mini) HDMI connectors. The other end consists of a POD, featuring either a LMH7322 (like the original), LMH7324 (cheaper quad channel part) or SNV65LVDS (much cheaper, less flexible) comparator. Mix-n-match is the keyword here, feel unrestricted in what pod to connect, get 4 LMH7322 based pods, or one of each. In the future, more pods may be added if it makes sense.As for the breakout board, there's currently two models, both with 50pin IDC connectors, matching the MSO5000 series and DHO900. The mini-HDMI variant was made to offer a super small/narrow profile, which is nice for the DHO900, but either work. In the future, given we have some testers/interest, we can very easily add a 68pin IDC variant for the DS1074 series, and very likely also for the PCIe based scopes such as the DSO7k and MSO8k series.Some words on the other great designs.Gandalf_Sr's Budget probe set design.https://www.eevblog.com/forum/testgear/ms05000-budget-logic-analyzer-probe-set-design/msg2938442/#msg2938442At first, it seemed like a good idea, but I didn't like that it wasn't open source so couldn't even respin it. Secondly, I liked the idea and even was planning on doing a pod for it, but the SNV65LVDS seemed more sensible at the time.S. Petrukhin's easy eda low cost probehttps://www.eevblog.com/forum/testgear/low-cost-logic-analyzer-probe-for-rigol-mso5000-easyeda-project/I really liked this design, but the many small comparators I didn't quite like, nor the flat cable design. But it was the thread that inspired me (after 3 years? to finally make my own design) after the suggestion of the SNV65LVDS. It was open-source though, but easy-edaNikki Smith's varianthttps://climbers.net/sbc/clone-pla2216-logic-probe-analyzer/Was what really maybe got me moving, as he did the work in KiCad and used the LMH7322 and LMH7324. I really wanted to have balanced lines (lapod all traces are length-matched). But, still wrong connectorI was still hung up on the HDMI bit. Also Nikki went silent after septemberdren.dk's first foss unithttps://gitlab.com/dren.dk/mso5k-la-pod/tree/masterThe name was actually inspired from this posthttps://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/msg2125477/#msg2125477LA pod. But 8 pins in a pod was not my liking, and flat cables.thmjpr's USB-C varianthttps://gitlab.com/thmjpr/stm32f03_la_monitorI do like the idea of using USB-C cables, but USB-C cables are a huge pain. are all wires routed, does it have an E chip, will that be in our way. Should we do USB-PD on the breakout board? Also, reversability is cool, but not ideal for the breakout.One major input for reference washttps://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/which includes a (measured) breakdown/schematic.Others I have missed? Regardless. Here's my variantAll schematics and stuffs come from the pipeline when releasedhttps://gitlab.com/riglol/lapod/-/releases,and I've attached a whole bunch of some WIP stuff herehttps://www.eevblog.com/forum/testgear/another-low-cost-la-probe-for-rigol-mso5000-by-oliv3r/msg5311123/#msg5311123Note, that I haven't ordered any PCB's yet, and nothing is tested. It just looks really sexy in the renderings :pEDIT 2024-02-03: Changed the starting post as we are now our own thread. Find below the remainder of the starting post(left-over of the original first post)I am too working on a respin of thismostly, because I wanted to use HDMI cables and 4 channels per pod. Here's my WIP screenshot; but it's far from finished. The pinout of the connector is crazy, causing all sorts of weirdness to be needed in routing bits, and to have at least the easiest routing, the connectors will end up having a weird order, J2, J4, J1, J3, which will translate to port1, will have pins 5 - 8, port2, 13 - 16, port1 1 - 4, port3, 9 - 12, which I admit is a bit odd, but keeps routing sane, or the size down, whichever you prefer.I'll route the other bits next (which is just power and gnd) and then route the pods.For those curious, I'll also attach a screenshot of the HDMI pinout to shout and shame

author: ebastler
author_rank: Super Contributor
timestamp: October 06, 2023, 03:47:09 pm
content: Quote from: oliv3r on October 06, 2023, 03:38:38 pmNot sure I understand how the pinout of the HDMI connector could drive the need to swap the sequence of the pods. I would expect the HDMI pinout to potentially force an awkward order of the four channelswithineach pod group, but the pod sequence to follow the order on the scope's connector?

author: UK
author_rank: Regular Contributor
timestamp: October 07, 2023, 10:41:06 pm
content: Quote from: oliv3r on October 06, 2023, 03:38:38 pmWhy HDMI exactly? Why not RJ-45 LAN cable? Moreover, Cat-7 / 8 cables have superior shielding for each pair, the connector with fixation also may be a very handy feature when a lot of stuff is going on on your table. Also, RJ-45 also has more robust contacts than an HDMI.

author: oliv3r
author_rank: Frequent Contributor
timestamp: October 07, 2023, 11:06:24 pm
content: Quote from: UK on October 07, 2023, 10:41:06 pmAll true, but RJ45 doesn't have enough pins. You can do 4 channels, but then have no power or anything. If you do all power pins, you end up with just 2 channels, which is usable, but leaves a lot to be desired ...HDMI cables are cheap and easy to get, and give you differential pairs too. The 5V pin is gonna be a challange, as cheap cables will not allow much current to go through, but must let 50ma go through at the very least to pass certification.Quote from: ebastler on October 06, 2023, 03:47:09 pmbecause the connector's pin-order isn't in sequenceSo i took the effort to make sure that the 4 pins within the HDMI connector are in order, so that took a lot of swapping. But swapping all pins for all connectors just takes way to much PCB space to keep the connector within reasonable size. Also, I wanted to keep the inner layers for power and ground, if I'd put signals on the inner layers, i could have swapped about a little bit more ...

author: UK
author_rank: Regular Contributor
timestamp: October 07, 2023, 11:34:09 pm
content: Okay, now it makes sense. But why not a Mini DisplayPort, it's smaller but has all the same.Or even a full-size DisplayPort, since it has a fixing feature.

author: oliv3r
author_rank: Frequent Contributor
timestamp: October 15, 2023, 09:02:03 pm
content: Those thoughts crossed my mind too, but mini-hdmi connectors are much harder to source; but what's worse, mini-hdmi cables are much harder to sourcealso, as you can see, from a size point of view, it doesn't matter much.same goes for displayport. HDMI you can get for a couple of € from action or poundshop or what not. They are 'ubiquitous'. Even when the HDMI consortium is evil

author: UK
author_rank: Regular Contributor
timestamp: October 15, 2023, 09:54:44 pm
content: By the way, how is it going with pin swapping to make all channels in order?

author: oliv3r
author_rank: Frequent Contributor
timestamp: October 16, 2023, 02:11:50 pm
content: for now 'not happening' :pso each pod will have properly ordered pins, just the main breakout won't (for now, but re-doing that one is simple now, only had redone it 5 times, due to size, manufacturing, differential matching mistakes); but if you look at the pinout you'll see why, they are just to spread out, but maybe i'll give it one more go later (or someone else :p) I'll post my WIP kicad files soon so that others can tinker with it.The problem, is that one channel will end up going from completely left, to completely right, meaning each trace will need to be this long, requiring a lot of space to snake around, thus the PCB will become bigger (sticking out the front more), which i'd rather avoid ...

author: oliv3r
author_rank: Frequent Contributor
timestamp: October 21, 2023, 08:29:06 pm
content: The first pod, based on the LM7324 is ready, and boy was it a party :pI'll do an LM7322 next, followed by some cheaper simpler chips as found in these threads.The current pod PCB size is 4.5 cm X 3.0 cm using all 2012 (metric) hand solderable bits. Using 0402 (metric) would be much more fun :p but that's an exercise left for actually producing these units with automated pick-and-place solutions.

author: UK
author_rank: Regular Contributor
timestamp: October 21, 2023, 10:31:57 pm
content: It looks sleek, but it would be great to add a small led on it.When you have a mess on the table, especially when you use all four pods it will be nice to have some illumination as to what pods are connected to MSO.

author: oliv3r
author_rank: Frequent Contributor
timestamp: October 24, 2023, 12:46:41 pm
content: Quote from: UK on October 21, 2023, 10:31:57 pmFair enough, I did add leds to the pod, to indicate which 'type' is connected (e.g. the LM7324 one will be blue, the LM7322 will be red + green). Having matching leds on the pod would be a nice idea, I'm a little worried with regards to power consumption.

author: oliv3r
author_rank: Frequent Contributor
timestamp: October 24, 2023, 01:56:26 pm
content: So the LM3222 was a lot easier to do, but (due to double the chips) is slightly larger. I've added an LED, though not sure how to make it visible later. I guess heatshrink instead of a case is certainly an optionOnce I've done all the pods, I'll size them up to be all the same size with the mounting holes in the same location, and the led as wellHere as before, big 2012 (metric) caps and resistors except for the differential resistors, everything should be length matched. Impedance matching is probably not the the case ...

author: oliv3r
author_rank: Frequent Contributor
timestamp: October 26, 2023, 12:05:00 pm
content: Finished the sn65lvds variant, which was the easiest and most pleasurable to route; also because it had the most space availableIt is basically Nikki's design, but with trace length matching, and using 4 channel pods of course.Gonna use this as the size of the PCB and cleanup the previous editions next, making sure the LED is on the same spot etc ...

author: oliv3r
author_rank: Frequent Contributor
timestamp: October 26, 2023, 12:11:11 pm
content: Read back this thread, and saw discussion about the need, or lack thereof, matching the traces for delay's. I know the scope doesn't match traces either, if we look at the X-Ray ...I never put the following pic onhttps://gitlab.com/riglol/rigolee/firmware/-/wikis/MSO5000%20teardown(cropped due to size restriction of the forum). I'll see if I can trace it out in kicad to determine an estimated trace length ...but again, rigol doens't care eitherRigol does care, I just found a pretty good shot which shows the serpentines clearly (bastardized to jpeg cause of forum)

author: ebastler
author_rank: Super Contributor
timestamp: October 26, 2023, 12:18:18 pm
content: I'm sure I have overlooked it somewhere in the thread, but could you please (re-)state the specifications of the LM7322 and LM7324 versions? Do they have configurable thresholds (in which range)? What's the range of input voltages and what is the speed? Thanks!

author: oliv3r
author_rank: Frequent Contributor
timestamp: October 26, 2023, 12:23:36 pm
content: Quote from: ebastler on October 26, 2023, 12:18:18 pmI have no idea, I just took other people's design, or rather, the LM7322 is the same chip used in the offical probe, which was reverse engineered. The LM7324 is a quad driver, hoped to be cheaper ...

author: ebastler
author_rank: Super Contributor
timestamp: October 26, 2023, 12:38:56 pm
content: Could you point to those designs you used as a starting point? I had come across a thread once which aimed to do a full-spec replica of the Rigol probe, but it is not this thread here, right?Also, could you restate the comparator part numbers please? Are theyLMH732x?

author: UK
author_rank: Regular Contributor
timestamp: October 26, 2023, 06:29:28 pm
content: Hey folks, just finished a shell for oliv3r's pods in Rigol's triangle style. The shell should print vertically as two halves without any supports. And as you can see it has a small oblong cutout and a light channel under it to make the LED shine in the center. It also has a flat lowering in the bottom for the label with channel numbers, which should prevent its easy pealing.Hope you like it!When oliv3r finalizes all PCB dimensions I'll do final refinements and upload STLs.

author: ebastler
author_rank: Super Contributor
timestamp: October 26, 2023, 06:34:31 pm
content: Nice! Looks very "Darth Vader" to me, matching the MSO5000.

author: oliv3r
author_rank: Frequent Contributor
timestamp: October 28, 2023, 12:40:41 pm
content: Quote from: UK on October 15, 2023, 09:54:44 pmQuote from: oliv3r on October 16, 2023, 02:11:50 pmSo it happened. I took some measurements and realized my current design was super small. Which is great, and would have fit, but I was under the impression, the traces aren't length matched within the unit, might as well just fix the ordering with different length traces. But turns out, it is probably length matched within the scope (lets just hope they didn't take the mismatch of the bods into account).Anyway, with the new measurements in hand, looking at the probe design, I figured, I'm so zoomed in, I can easly spare 3 - 5 mm. Also, I've learned how to do _proper_ differential track length matching in kicad (did it manually per track before, which was of course not good), figuring that would save me quite some space too. It did, but also using the 4 layers gave me plenty of beef to work with. So without further ado, correctly ordered breakout.Also attached is a screenshot of what it looks like on the various layers.Next steps, adding kicad automation to generate all the outputs from the pipeline, addinga pipeline, putting it all in git and pushing it to gitlab.Also, some silkscreen fixups, attributions etc are deff. also in order. I really should fork this to its own topic too ...

author: ebastler
author_rank: Super Contributor
timestamp: October 28, 2023, 01:07:50 pm
content: Congratulations on solving that puzzle -- nice job!EDIT: Looking again at the layout, I think there is a bit more puzzling to be done. The orange traces in general don't look length-matched to me; the traces for IN9 in particular are much shorter than any of the other pairs?On the silkscreen, and also when you create a new thread about this, I would not call it an "MSO5000" LA board. The new DHO900 series (low-cost 12 bit scopes) uses the exact same pinout for the LA probes, and will certainy get a lot of attention. So be sure to let those users know about your probe too!If you could take a moment to address my earlier question? Thanks!Quote from: ebastler on October 26, 2023, 12:38:56 pm

author: tooki
author_rank: Super Contributor
timestamp: October 28, 2023, 01:45:45 pm
content: Quote from: UK on October 07, 2023, 11:34:09 pmThe full-size DisplayPort is possibly the least-reliable connector I have ever encountered. Because of how the plugs are implemented (a PCB with the contacts soldered to each side, and the wires from the cable to that PCB, but not overmolded because of the latching release button), they are extremely susceptible to damage from bending. Literally every DP cable I’ve encountered in the wild has had to be replaced at least once. Mini-DP is a far more robust connector.Quote from: oliv3r on October 15, 2023, 09:02:03 pmThey didn’t say mini-HDMI, they said mini-DisplayPort. They are available.The biggest risk with using popular connectors like HDMI for some other signal is what happens if someone connects a cable with an actual HDMI signal to it. (Not entirely crazy, given how modern scopes have HDMI outputs.) Will it damage your device? Will it damage the HDMI device?In this regard, a more obscure connector — or one which was not designed specifically for a common consumer use — is a better choice.

author: ebastler
author_rank: Super Contributor
timestamp: October 28, 2023, 02:14:02 pm
content: Quote from: tooki on October 28, 2023, 01:45:45 pmAt least oliv3r is in good company there: Siglent use an "HDMI" connector for their proprietary S-BUS interface to an external logic analyzer module. It's right on the front panel of various entry-level scopes.Looking at the renderings above again, I have a different concern about the full-size HDMI connectors though:@oliv3r, is there enough room for the HDMI plugs' plastic bodies?Looks like the jacks are spaced very closely together.

author: UK
author_rank: Regular Contributor
timestamp: October 28, 2023, 02:44:35 pm
content: And I think so too, there isn't enough space between the ports... especially for standard cheap cables.As a possible option to solve the problem with the PCB dimensions is to swap the current HDMI sockets to the upright/vertical version.

author: ebastler
author_rank: Super Contributor
timestamp: October 31, 2023, 08:40:08 am
content: Quote from: ebastler on October 26, 2023, 12:38:56 pmAnswering my own question, since oliv3r seems to drop in only sporadically:The thread on analyzing and replicating the original MSO5000 logic probe (PLA2216) is here:https://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/.And the comparators are indeed the LMH7322 (dual comparator) and LMH7324 (quad). Both are available from Mouser etc., and both are on the expensive side.Regarding the form factor of a logic probe, I am not sure whether I prefer Rigol's approach (all 16 channels routed to a large external pod) or oliv3r's (4 pods with 4 channels each). Rigol's design clearly limits flexibility, requiring all 16 probed channels to be relatively close to each other on the PCB under test; and it has the bulky, broad flat cable connection. But four HDMI cables can get a bit messy too...And it's worth mentioning thatRigol tells you not to hot-plug the logic probe connector! Having those individual HDMI-style jacks on the front may just be too tempting?The other thread has one version with4x4 channels, but using USB-C connectors-- debatable, since inserting the plugs the wrong way round will swap the channels, it seems. It also includes a design for2 pods with 8 channels each, connected via narrower flat cables. That one might actually hit the sweet spot for me -- but I am not sure whether it was fully polished and tested.

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 01, 2023, 04:42:48 pm
content: Quote from: UK on October 26, 2023, 06:29:28 pmThat looks friggin sexy as heckcan you also do one for the breakout board? Here's the dimensions I have for now, but since the boards aren't proven to be working (haven't built them yet) can't say that it won't change (but I have to doubt that ...)The slot in the middle for the led looks uberniceshould be doable with a light-guide, hotglue usually works great :p However, I'm not sure I can get the LED in the middle like that, see the dimensions I have for now. I could wiggle in the LED between the resistors and the connector, but probably will need to enbiggen the PCB a little ...The breakout doesn't have mounting holes, shouldn't be an issue with proper dimensions I suppose, but there isnt' much room to add them either ...

author: ebastler
author_rank: Super Contributor
timestamp: November 01, 2023, 05:06:20 pm
content: A 17 mm pitch is definitely not going to work for the HDMI sockets. The slimmest HDMI plug I can find in my home is 20 mm wide.I find it a bit frustrating that you post something and disappear again for days right away, not responding to any questions or concerns. Yes, you can use this forum as a one-way broadcastig channel, but you are losing the opportunity to improve your design, and may lose your audience. Personally I would rather roll my own PCB design, because it seems increasingly unlikely that you will listen to suggestions.Edit: Strikethrough.

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 01, 2023, 05:18:34 pm
content: Quote from: ebastler on October 28, 2023, 01:07:50 pmYou are right!! The orange ones are the longest traces, so figured those would be easiest and could be done last, but forgothere's the traces lengthen :pQuote from: ebastler on October 28, 2023, 01:07:50 pmI called it LA14 before, just cause ... but please, come up with some cool namesQuote from: ebastler on October 28, 2023, 01:07:50 pm

author: ebastler
author_rank: Super Contributor
timestamp: November 01, 2023, 05:42:03 pm
content: Quote from: oliv3r on November 01, 2023, 05:18:34 pmThe Rigol logic analyser probe it replaces is the PLA2216. "PLA2216 replacement" would be clear but not cool... Maybe "PLA2216 plus" or such, because it is actually better than the original (from a handling perspective)?QuoteNo, those are not the correct numbers, that's why I asked. LM7322 is a plain old op-amp; LM7324 does not exist at all. It'sLMH732x. Should be fixed on the silkscreen of the probe PCBs!QuoteThe present thread is the "low cost probe" one, which originally focused on the cheaper CMOS/TTL-level pods only. As mentioned a few posts above, I have found the other relevant thread in the meantime. It looks into using the original LMH732x comparators, and has a few schematics and layout suggestions for those:https://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/.

author: UK
author_rank: Regular Contributor
timestamp: November 01, 2023, 07:22:29 pm
content: Quote from: oliv3r on November 01, 2023, 04:42:48 pmSure, but it will definitely take some time with my current job.Quote from: oliv3r on November 01, 2023, 04:42:48 pmI'm glad you like it too. I've dived a bit deeper into the MSO5000 look and made several touches... now it definitely looks in its authentic style.

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 01, 2023, 08:26:44 pm
content: Quote from: tooki on October 28, 2023, 01:45:45 pmSure, but this is a built for experts isn't it? I'm not gonna run production and sell millions of them to unsuspecting users :pSo if you connect your PC or laptop to your scope, the laptop's HDMI port will probably be damaged, as it's outputting power on the I2C pins at the least. Don't think the scope will care much, as all those extra used pins, are either to drive a led on the adapter, or to feed power from the adapter.Sure, people do dumb things, but again, this isn't a consumer dumb device, and while I agree, safety first, and using a common consumer connector is a dumb idea for a commercial product, this isn't thatBut getting consumer HDMI cables, is easy and cheap, and they are differential pairs to boot. I just got 60cm HDMI cables for 25cents each (the shop was closing down, but still). I think even normal HDMI cables can be had for 2€ nowadays. But yes, the resistance of the voltage carrying wires will have an impact ...

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 01, 2023, 10:22:31 pm
content: Quote from: ebastler on October 28, 2023, 02:14:02 pmcrap! I Didn't even think about that one ... i'll measure my cables and adjust accordingly. Only bit that's frustrating, is that'll probably mean I have to do my differential lines, again, and the longest one will probably be ending up even longer :SOh well!!Quote from: ebastler on October 31, 2023, 08:40:08 amtrue, but often threads are silent for days, and ... life happens.Quote from: ebastler on October 26, 2023, 12:38:56 pmthat's the one! the third pod is the one from this Nikki Smith's remix, he called it 'v3.1' or something.Quote from: ebastler on October 26, 2023, 12:38:56 pmYeah, but cables end up always being messy, 8 cables is still too much for most of my tasks and still a big-ish cable. Also, those flat cables aren't differential cables, which is why I dislike them. 4 was the sweetspot for me, not just because hdmi has exactly 4 differential channels, but also because 4 is what you'd use for i2c + irq, or SPI + irq etc. And it does scale to use both :p one can always even do a pod with dual hdmi sockets :pQuote from: ebastler on October 26, 2023, 12:38:56 pmI think this thread, and nikki's v3 are then just what you are after. I didn't like the USB-C for the same reason, reversability AND the actual problem of more easily plugging something incorrect in. HDMI just felt 'less likely'. Initially I really wanted to do mini or micro hdmi even, and with the rasp-pi they seem slightly easier to source now ...

author: ebastler
author_rank: Super Contributor
timestamp: November 02, 2023, 08:43:23 am
content: Quote from: oliv3r on November 01, 2023, 10:22:31 pmMaking the PCB wider might also run into collisions with the connector on its left -- even more so on the DHO900, which has a USB jack quite close to the logic analyzer port. Maybe look into mini-HDMI or mini-DVI again?QuoteAgree that 8 signals plus 8 GND wires is a lot already. I am not sure why all the individual GNDs would be needed though. My preference for an 8-signal pod would be a 2*5 pin connector (8 signals, 2 GND). That also works well with an IDC connector and colored ribbon cable, with the colors nicely matching the channel numbers.QuoteNikki Smith did an updated version of the low-cost (TTL/CMOS) probe only, right -- or did I overlook something? I definitely want a probe with the large voltage range and configurable threshold provided by the LMH7324, since one of my use cases is work on vintage (tube) computers with 20V logic levels.The design by @dren.dk is the configuration I personally like best,https://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/msg2316423/#msg2316423.It needs some work though: Some signal polarities are flipped due to early mis-information about the 50 pin connector's pinout, and he did not bother with length matching of the traces.But I am in no rush -- will wait how your design pans out, and probably borrow (and use in duplicate) your very nice LMH7324 pod layout.

author: UK
author_rank: Regular Contributor
timestamp: November 02, 2023, 09:30:35 am
content: Quote from: ebastler on November 02, 2023, 08:43:23 amWhy not just use vertical ones?!Previously, I also suggested mini-HDMI and mini-DP, but after looking at the range of cables available I agreed that the ordinary HDMI is the best solution... since slim connectors, flat or soft versions of cables are not even available for mini-HDMI / DP / DVI ...unless you're a fan of cables that look like a garden hose on your tableQuote from: oliv3r on November 01, 2023, 10:22:31 pmIf you going to redo all differential lines again )) pls look closely at the upright HDMI sockets I've already mentionedbefore. Then you won't have to make a board that looks like a palm tree. And all four HDMI sockets can fit on a pcb in the width of a 50-pin header.

author: ebastler
author_rank: Super Contributor
timestamp: November 02, 2023, 09:45:15 am
content: Quote from: UK on November 02, 2023, 09:30:35 amThey are certainly worth a try in the layout! But it seems to me that you will have to add more depth to the PCB: The connectors themselves are longer than the standard horizontal ones, and on the MSO5000 you might also need to give them extra clearance so they don't collide with the protruding scope housing above the connector.If that PCB becomes to deep, and then has four full-size HDMI plugs and cables dangling from it, I would be worried about mechanical strain -- and about bumping into when you want to use the touch screen. Also because the assembly would come closer to the touch screen since it is taller. And it might just look a bit awkward, with the HDMI connectors sitting much higher than the row of BNC jacks and USB.Having written the above -- maybe the vertical HDMI connectors should sitbelowthe PCB? It might still look awkward, but you avoid the collision with the scope housing, and the plugs and cables would be further away from the touch screen.

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 02, 2023, 08:21:09 pm
content: Quote from: ebastler on November 02, 2023, 08:43:23 amHmm, I'll check the sizes again, my el-cheapo cables are at 21mm, so 22.5 mm would be the minimum with for each connector. That would yield 900mm total width, which seems to fit the MSO5000 it seems. Using a ribbon extension cord is an option, but defeating the purpose of courseBut if you find a mini-hdmi port on lcsc we can talkWhat is spacing like on the DSO900? That USB connector is awfully close. I was thinking of doing double sided connectors (J1 J2 top, J3 J4 bottom, but those solder lugs get in my way. Offsetting things so both holes overlap, e.g. 2 connectors in 1 hole is an option, just not solderable one. Getting connectors without the lugs is an option, but makes it much to easy to 'rip off'...I suppose a nother option is an ugly one, current design for the MSO5000, an asymmetrical for the DSO9000, and have it stick out only to the right side. Since the boards carry no components, they are cheap as butt of course, just the design effort.Quote from: ebastler on November 02, 2023, 08:43:23 amI think this also comes from the fact, that you may want to have a (coax) wire per signal, and connect each individually to power and signal? Use nice coaxial mini cables? idk, i'm not EE enough (at all) to know what's the better design idea here. For me, using a single row or double row header doesn't make a difference, and I think a 5 pin (or 6) single row might actually be wider then the HDMI plugQuote from: ebastler on November 02, 2023, 08:43:23 amVery true, it was the first design I looked at actually, because it was in kicad, and I had forgotten about dren.dk's, which I re-found and used to do the LM variantsQuote from: ebastler on November 02, 2023, 08:43:23 amKeeping the HDMI connector on the pod isn't unreasonable, because you can't make the pod much smaller anyway, as most space is used by those 2012's that are needed. You could use smaller components there, but then traces could become an issue ...Quote from: UK on November 02, 2023, 09:30:35 amI actually had considered those as well, (I need HDMI connectors for another project actually, and I really wanted a normal and a reverse (e.g. upsidedown) HDMI connector) but these things are almost impossible to source ...So the vertical ones, are ugly :p and then stick out either at the top, or the bottom (and I can't place the LED in the center) But yes on all other points. But the breakout board can be done in various versions :pNot that cost is the major driving force (well the topic suggests otherwise), the vertical ones do cost 10x more then the normal ones (65c vs 7c)Also, I'm not convinced it would make layout any easier, the board might end up being even longer due to the size of the connector, and on top of that the connector sticks out quite a bit, and we still need some jigglies to route the pins ...So while I certainly feel the challenge, I'm worried about its use/success :p Unless I hear a lot of shouts to do it anyway :p But feel free to tryI'd share my PCB file, but the forum won't let meso i've renamed it to .txt

author: mwb1100
author_rank: Frequent Contributor
timestamp: November 02, 2023, 09:39:29 pm
content: Quote from: UK on November 01, 2023, 07:22:29 pmThose do look nice!

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 03, 2023, 06:41:11 am
content: Them new dimensions look something like this, 85mm it looks like atm, dunno if i can route it though

author: ebastler
author_rank: Super Contributor
timestamp: November 03, 2023, 07:31:17 am
content: Thanks for sharing the draft. For the DHO900 series, 85 mm would already be too wide, I'm afraid. As mentioned earlier, I don't have the scope (yet). But I took a photo from the net and used the connector width for scale -- attached.The circuit board itself would probably already get in the way of inserting a USB stick or plug. If you add an enclosure for the breakout board or an HDMI plug in the leftmost position, it would definitely block the USB port.LCSC do offer mini- or micro-HDMI connectors, by the way -- they just don't put that in the part name and have no way to filter for them...Part numbers C2962409, C2962410, C720620 for example are all micro-HDMI connectors which are in stock and cost around $0.50 each. C2962409 and C720620 are also available for JLCPCB's assembly service. Not the friendliest parts for PCB layout though: Those pads are fine-pitched, and I don't see a way to get to the inner row without dropping down to another layer.Edit: Switching to mini-HDMI would add a bit of parts cost, both for the jacks and the cables. But not significant compared to the LMH732x cost, I'd say. If you don't want to bet on mini-HDMI entirely, there could always be two versions of the breakout board. Probes should keep the full-size HDMI connector in any case, since cables with mini-HDMI onbothends seem very uncommon.Edit²: Removed the picture, since the scale was not correct. See UK's post below for a corrected picture, which shows an even bigger interference.Edit³: Oops, the HDMI part numbers above are actuallymicroHDMI (type D), it seems. They would definitely fit, but may be unnecessarily finicky (both from a layout perspective, and regarding handling/robustness of the plugs). Proper mini-HDMI (type C) connectors are available too, e.g. C2682170. More layout-friendly since they bring all pins out in a single row. Also they are mechanically more sturdy than the micro variant, and should be small enough to fit the four connectors on a breakout board which is not wider than the 2*25 pin port.

author: ebastler
author_rank: Super Contributor
timestamp: November 03, 2023, 08:28:01 am
content: One more comment, if I may, regarding the LMH7324-based pod from reply #155:The blocking capacitors for the various supply voltages are place a bit too far away from the LMH7324, for my taste. Especially when considering that we are already making compromises with the inductance by using the larger 0603 parts and 100 nF caps only (as used by Rigol too), vs. the (additional?) 10 nF suggested '7324 datasheet.If you drop the differential output signals down to another layer right away, you would have room for the capacitors directly to the left and right of the '7324. You could bring the differential signals back to the top layer in a convenient place, just below the RN1 and RN2 arrays. That would also allow you to use arrays for the 220 Ohm termination resistors, placed just below RN1 and RN2 respectively.Oh, and one more thought: When length-matching the four channels on the pod, it should be sufficient to make thetotalof "trace length on the input side + differential trace length on the output side" equal for all channels. It looks to me like, at the moment, you have separately balanced everything on the input side, and also on the output side. Maybe you can save a few wiggles and some PCB space?

author: UK
author_rank: Regular Contributor
timestamp: November 03, 2023, 08:32:12 am
content: Quote from: ebastler on November 03, 2023, 07:31:17 amYour illustration has a bit of a smaller scale... here is a real scale of 85mm, and a vertical port illustration as well.Still do not realize why you think that vertical HDMI ports look ugly since most of the Rigol scopes have vertical USB ports on their front panels, even Rohde & Schwarz have the same.

author: ebastler
author_rank: Super Contributor
timestamp: November 03, 2023, 08:45:22 am
content: Quote from: UK on November 03, 2023, 08:32:12 amIndeed, thanks for double-checking. I'll remove my attached picture since it is misleading; not sure where my scale error crept in. So the collision with the USB port is even worse.What I dislike about the vertical ports is not the vertical orientation of the plugs themselves, but the fact that they sit so low (or high). All other connectors on the front are nicely aligned to the same height. That's just aesthetics and personal taste, however. The fact that the PCB will have to be deeper to accommodate the vertical jacks, and hence the plugs and cables would stick out further, does have handling implications though. Especially relevant for users who have the scope on a shelf or stacked on top of other instruments, or mounted on a VESA arm for the DHO900: In all these configurations the cables get in the way when you reach up to the touch screen, hence should protrude as little as possible.

author: UK
author_rank: Regular Contributor
timestamp: November 03, 2023, 09:05:08 am
content: Aesthetics can be easily achieved just with top-oriented HDMI sockets and IDC connector under the pcb, that also make the board more flush with the panel

author: ebastler
author_rank: Super Contributor
timestamp: November 03, 2023, 09:20:18 am
content: That could work. But apparently you need an extra-tall connector to reach into the scope, at least for the MSO5000. dren.dk used this arrangement in his design and chose this somewhat exotic connector:https://www.mouser.dk/ProductDetail/200-ESQ12523LDEdit: What's wrong with mini-HDMI?

author: UK
author_rank: Regular Contributor
timestamp: November 03, 2023, 09:47:40 am
content: Quote from: ebastler on November 03, 2023, 09:20:18 am1. It's double as weaker than full-sized HDMI, while HDMI itself is not the strongest one.2. Poor range of cables, their availability, and a bit higher price.So I prefer to pay extra once for a taller IDC header than for useless mini-HDMI cables if this could count as an argument.

author: ebastler
author_rank: Super Contributor
timestamp: November 03, 2023, 10:15:13 am
content: Quote from: UK on November 03, 2023, 09:47:40 amBoth are valid points to consider, of course, but I don't see show-stoppers there. Mini HDMI is specified for 5000 plugging cycles vs. 10000 for full-size; seems more than enough for me. (Remember, you are not allowed to hot-plug the Rigol logic probes anyway!) And four cables including shipping start from 8.50€ on AliExpress or 12€ on Amazon, and there are many offers.So I don't know about "useless" for mini-HDMI... But isn't it nice that we can have different breakout boards easily, all using the same pods with full-size HDMI plugs?

author: UK
author_rank: Regular Contributor
timestamp: November 03, 2023, 01:46:39 pm
content: Quote from: ebastler on November 03, 2023, 10:15:13 amWeaker meant not about plugging cycles, but the rigidity and strength of the connection, as well as the gripping force of smaller contact pads... since that's not a connection behind your TV (where nothing happens), it is a workbench and you can easily do!!!hot-unplug!!!just by accident while using the LA. That's why earlier I suggested a full-sized DP-port with its fixing feature.Summarizing the arguments above, reducing the size of the connector increases the chance of accidents!Quote from: ebastler on November 03, 2023, 10:15:13 amAll my photo and video stuff use micro-DP or micro-HDMI and it is more common nowadays, several 4th and newer 5th PIs also use micro-HDMI... that's why it's useless cable.Quote from: ebastler on November 03, 2023, 10:15:13 amWhen I'm talking about availability I mean I don't want to wait about a month for delivery from AlixresssAfter all, if we back to the beginning main oliv3r's point was the versability when you can take any HDMI cable lying around and use it with LA and that's really cool! And mini-HDMI is not cool at all, except for the size of the connector.... moreover, overall savings are just a couple of millimeters at the sacrifice of reliability and rigidity of the connection.

author: ebastler
author_rank: Super Contributor
timestamp: November 03, 2023, 02:19:17 pm
content: Alright -- many of these aspects are a matter of personal preferences, I think.I would definitely prefer to have a complete set of probes, cables and grabbers in the drawer anyway, so re-using existing cables is not important to me. While the micro-HDMI connectors feel flimsy to me, mini-HDMI seems sturdy enough. And yes, I would probably also be too impatient to wait for AliExpress delivery; so I'd spend the extra 3.50€ to get four cables from Amazon...Anyway, the nice thing is that we don't need to make a hard-and-fast decision here, but can have both versions of the breakout board. If oliv3r prefers a different solution, I could always roll my own mini-HDMI version. (Or go with the 2*8 probes and fine-pitch ribbon cable; still pondering on that decision...)

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 03, 2023, 09:52:16 pm
content: Quote from: ebastler on November 03, 2023, 08:28:01 amI got them as close as I could, there's traces underneath for power already, so dropping them isn't an option really. The caps are 6mm away, which I admit is further then I'd prefer too. Also, I really wanted to avoid via's, as that introduces other problems of course. There's always the possibility to add extra caps at the bottom though, like what dren.dk did, but I didn't want to compromise on the heat dissipation ability, as the bottom plane is where the ground plane gives the heatsink, adding those capacitors reduce that by quite a bit.The only real alternative I can come up with, is route the signals on the left/right outside, and keep the top area for the capacitors, but that would make the traces considerably longer, about 3x as long is my guess. So then I ask you, is that worth it? Is it okay to have traces that are 3x as long?oth, they are on the differential side, and adding a few cm shouldn't be a big issue. Let me mull on that for a bit.QuoteAll traces, from the 50 pin connector, to the output pin, should all be exactly the same length for each signalI didn't length match pairs only, For obvious reasons, if I measure a 2 channel signal, across 2 pods, I don't to care which input is matched, but want to ensure the delay is identical everywhere. That's why some of the lines look a bit weird, while not being snakes, because they are length matched too.

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 03, 2023, 09:56:39 pm
content: Quote from: UK on November 03, 2023, 08:32:12 amVery truejust the parts themselves I suppose, and it'll make the breakout board 'fat' :p idk, just a feeling if anything.I'll print the current draft on paper, and see how it fits on the mso5000; doing a mini HDMI breakout for the DSO900 is a fun exerciseand nice to have. The vertical jacks though, they make sense logically, as it also saves on using via's :p but the extra depth, extra height put me off. I even liked the vertical connector idea, but those special IDC connectors make me a bit cringe :pSo with all the feedback, I'll start again, bring caps closer, increase the width to fit the plastic, do a mini hdmi variant :pedit: Suppose if you've done it 8? times, it goes a lot faster :p

author: ebastler
author_rank: Super Contributor
timestamp: November 03, 2023, 10:26:35 pm
content: Quote from: oliv3r on November 03, 2023, 09:52:16 pmI did not express my thought well, I'm afraid. I realize that you have properly length-matched everything, and that it must have taken a lot of tweaking!What I meant to say is that you can potentially simplify the length-matching. It looks to me like, on the pod PCB, you have (a) length-matched the 4 signal traces from the 2*4 connector to the LMH7324, and (b) also length-matched the 8 signal traces from the LMH7324 to the HDMI connector. But the requirement is only that the sum "length of trace before + length of trace after" the LMH7324 need to be matched between the four channels. So two of the channels may have shorter traces from the input connector to the near side of the LMH7324, and compensate by having longer traces from the LMH7324 to the HDMI.This thought doesn't matter if you do not need to touch the layout any further; it is clearly good as it is. But if you needed to move things around, get the capacitors closer or such, it might help to work with that relaxed constraint, because it can probably reduce the overall trace lengths and wiggles somewhat.QuoteOK, I have not seen the inner layers of course. If they are too busy, my suggestion may be impractical -- never mind!I would also prefer to keep the bottom side free of components -- better heatsinking, more mounting options, also easier to home-build.

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 04, 2023, 08:26:19 am
content: Quote from: ebastler on November 03, 2023, 10:26:35 pmYeah, I thought of that too, but that's actually harder, because then you need to do math a lotkicad can't relate and sum traces between components. Also the 'win' there is minimally anyway, but a descent idea anyway.I'll try to route the traces around the capacitors, to get them closer. I realized, the extra 1 - 2 cm are insignificant, as a) they are differential digital signals, and b) look at the wiggles on the breakout board, I'm not carying about length there either ...Regarding the HDMI vs mini/micro HDMI discussion, before the raspberry pi, mini-hdmi is something I always thought of, as those cheap tablets used to have them, so there always was some availability. But with the PI, getting cables might actually be quite feasable, so micro HDMI might not be that weird to aim for. I'll have to look at the pinout, but routing may not be a problem either, as the signal traces may be at the top row, and the bottom row be the grounds.So then, mini-hdmi or micro-hdmi I wonder, they cost about the same, so that's not the issue.edit: The signals are not all on the top, so routing would be much more painfull, so for now, i'll try mini-hdmi

author: ebastler
author_rank: Super Contributor
timestamp: November 04, 2023, 09:04:48 am
content: Quote from: oliv3r on November 04, 2023, 08:26:19 amTechnically, mini-HDMI is probably the better choice: A bit sturdier if one bumps against the plugs by accident, and small enough to fit all four connectors onto a PCB not wider than the scope's port.Future-proofing might speak in favor of micro-HDMI. As devices keep getting smaller, micro-HDMI is probably taking over and mini-HDMI cables will become harder to get in the long run. But I would not be overly concerned about this: You don't need to plan for a 10-year production lifecycle, and if push comes to shove someone could always add a micro-HDMI breakout board later.

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 04, 2023, 09:27:27 am
content: How do we feel about this? In terms of dimmensions, the PCB itself is now 68mm wide

author: ebastler
author_rank: Super Contributor
timestamp: November 04, 2023, 09:34:39 am
content: Quote from: oliv3r on November 04, 2023, 09:27:27 am

author: UK
author_rank: Regular Contributor
timestamp: November 04, 2023, 09:51:54 am
content: Quote from: oliv3r on November 04, 2023, 09:27:27 amIt looks neat, but it also looks like a big lever and possible strain on the scope port... which will clearly affect its service life.Quote from: oliv3r on November 03, 2023, 09:56:39 pmIs there any real reason for that cringe?! it definitely will put less strain on the scope port.Also, LEDs can be more visible from the front view, especially while using the DHO900 on the vesa mount.

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 04, 2023, 10:20:25 am
content: Hmm, that mini-HDMI part is intended to be 'in-pcb' mounted, e.g. requiring a cut-out. If you can find another mini-hdmi port that's 'just flat' that'd be goodQuote from: UK on November 04, 2023, 09:51:54 amThe cringing part is that it's quite deep, but more importantly, it's a single-supplier part, it costs 10 times more then a regular connector (9 euro's a piece), will make routing probably quite hard, also because it's a through-hole part.Yes, the led's visibility will be better, but then there's also 'side-entry' RGB leds. I simply used this one because I used it in a different project (and it's nice and big, side entry RGB's tend to be super small)

author: UK
author_rank: Regular Contributor
timestamp: November 04, 2023, 10:27:01 am
content: I agree with you point. I've just recall that also already used 'side-entry' leds on several projects.

author: ebastler
author_rank: Super Contributor
timestamp: November 04, 2023, 11:07:01 am
content: Quote from: oliv3r on November 04, 2023, 10:20:25 amLCSC part number C2682170, you mean? Doesn't look to me like it would need a cutout. Were you looking at the same drawings?https://datasheet.lcsc.com/lcsc/2110112030_XKB-Connectivity-A71-05H4-111N1_C2682170.pdf

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 04, 2023, 10:06:32 pm
content: Quote from: ebastler on November 04, 2023, 11:07:01 amNo, I used the wrong part, well a different part, which did have the cutoutI saw the name in the pdf, which made me trigger that it was the wrong one. I have too many HDMI parts in my lcsc library now :p

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 04, 2023, 11:00:15 pm
content: Anyway, lets break down our options for a moment.'top full-szie 2x2' entry:cons:* requires expensive extra deep/long IDC connector, hard to source, single supplier* vertical HDMI connectors sticking out quite a bit to the front* 'base' quite 'high' (top-bottom)* vertical HDMI connectors have many connection pins, but put a lot of strain on the connectorpros:* easily fits 4 connectors* standard leds easily face forward* strain on the connectors is more equally distributed?vertical HDMI connectorscons:* increases height (makes the breakout fat) and sticks out further due to their longer length* leds sit next to the connector, making it harder to identify 'is it the one to the left or right'pros:* makes all connectors fit nicelymini HDMI connectorscons:* cables are harder to source* connections are less strong due to the more fragile connectormicro HDMI connectorscons:* Much harder/more ugly to route* much more fragile* cables not the easiest to source (but certainly possible)full HDMI connectorspros:* easier to route* much more robustcons:may not fit on non-mso5k(I'm sure we can increase and work on this list more :p) but for now, I think just doing two layouts, mini and full boards. We can always do a 3rd or a 4th too :p the breakout boards are after all the easiest to do. If for example you have both an MSO5k and a DSO900, you may get one each or just use 2x2 one

author: ebastler
author_rank: Super Contributor
timestamp: November 05, 2023, 07:41:48 am
content: Quote from: oliv3r on November 04, 2023, 11:00:15 pmThanks! I agree that having two options, mini and full-size HDMI, should cover all bases.For the full-size version, I quite like UK's 2*2 proposal. Maybe the exotic, tall 2*25 connector can be avoided by simply stacking two regular connectors and glueing them together? For the HDMI connector, C168715 looks like the only LCSC part which is meant to be mounted that way. (They also have C2962411 and C711355, which are sold for SMD mounting on a PCB edge but could probably be "abused" as vertical through-hole parts.)Those vertical connectors should get some mechanical support from a 3D-printed enclosure. But I trust UK will find a stylish solution there!

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 05, 2023, 02:49:31 pm
content: Quote from: ebastler on November 05, 2023, 07:41:48 amI wouldn't dare putting all those cable stresses on an SMD footprint, but without further ado, the mini HDMI versionOne thing I just realized, is that I didn't match the PCB size, but then it also shouldn't matter so much, as the width is different anyway, so having the same depth doesn't add any value.I did swap the LED pins on the HDMI connector, so I'll have to go back to the other bards and fix that, but still, I think this came out well.

author: ebastler
author_rank: Super Contributor
timestamp: November 05, 2023, 04:23:28 pm
content: That looks very nice and tidy!When I mentioned the "board edge" HDMI connectors, that may have read a bit confusing. If you look at the drawings for the three part numbers I mentioned, you will find that they all look very much the same, but the manufacturers give different footprints for them: One with vertical mounting, and through-holes for the mechanical mounting tabs as well as all the pins. The other two for mounting horizontally on the board edge, with the PCB between the two rows of pins, and SMD mounting only. But the parts seem to be more or less the same, so all three could probably be mounted vertically (with through holes).Anyway, as long as the C168715 part is in stock, that's probably the one to get, because one can be reasonably sure that the footprint is correct.

author: UK
author_rank: Regular Contributor
timestamp: November 05, 2023, 04:46:57 pm
content: Quote from: ebastler on November 05, 2023, 07:41:48 amFor sure!Quote from: ebastler on November 05, 2023, 07:41:48 amHere you go, C5204145 , C2682172 and short one C711353Quote from: oliv3r on November 05, 2023, 02:49:31 pmThat's true! May be I missed that but why you didn't route channels D0 and D16?

author: ebastler
author_rank: Super Contributor
timestamp: November 05, 2023, 05:30:43 pm
content: Quote from: UK on November 05, 2023, 04:46:57 pmOh, nice! It is reassuring to see that there is a larger selection. I had scanned through the thumbnail pictures too, not trusting LCSC's keywords, but did not see (or recognize) those.I wonder what the "brick nogging" tag means? Is that a standard industry term or the unexpected result of a Chinese-to-English translation?Edit: Ah....Quote from: niconiconi on July 21, 2022, 07:56:24 pm

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 06, 2023, 01:47:12 pm
content: So here's the new LM7324 POD with the capacitors hugging the chip as closely as possible.One thing I just came to realize though, is that the pin-order on the POD's are all 3, 2, 1, 0. This was due to the breakout board, swapping that order makes routing really really hard, as all lines cross each other. I don't know how the original pod solves this, or if the order is also backwards? But the solution is of course simple, flip the pod aroundbut that puts the led on the bottom, and since I don't want to do dual-sided components ... maybe I'll do the leds on both sides ....Flipping the connector btw won't help that much, because it's a side-entry connector, so flipping it just puts it up-side down, but pin 0 is still on the right ...Quote from: UK on November 05, 2023, 04:46:57 pmI don't understand, they are routed aren't they?

author: ebastler
author_rank: Super Contributor
timestamp: November 06, 2023, 03:06:26 pm
content: Quote from: oliv3r on November 06, 2023, 01:47:12 pmCool, that layout looks really nice and tight now!I would not worry at all about the bit order. To the contrary: Isn't that how multi-digit binary numbers should be written, low bit on the right?

author: UK
author_rank: Regular Contributor
timestamp: November 06, 2023, 03:36:03 pm
content: Quote from: oliv3r on November 06, 2023, 01:47:12 pmI've read the mask on the board with mini-HDMIs - 1-3,4-7,9-11,12-15... looks like 0 and 8 are missingQuote from: oliv3r on November 06, 2023, 01:47:12 pmI forgot to tell you last time, that the length of the PCB should be extended for proper placement of the 8p socket, since it has to be lying on the PCB (at least half of it) and not floating in the air. Because anyway we have this empty space in the shell under the 8p socket. So then if the length will be extended and we get additional PCB space, why just not reroute the pins order on the PCB backside like this?After all, we have 6 spring-connection points for each channel, so 2 more VIAs should not drastically affect on the signal.

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 06, 2023, 07:47:35 pm
content: Quote from: UK on November 06, 2023, 03:36:03 pmohh, fair point, the silkscreen is wrongQuote from: oliv3r on November 06, 2023, 01:47:12 pmI forgot to tell you last time, that the length of the PCB should be extended for proper placement of the 8p socket, since it has to be lying on the PCB (at least half of it) and not floating in the air. Because anyway we have this empty space in the shell under the 8p socket. So then if the length will be extended and we get additional PCB spaceI wanted to keep the PCB length <5cm because that's where you get the cheaper rates with the board houses, or you can put 2 on a 10x10 boardI realize its floating in mid air, and would only be held in place by the solder and the housing, which is a bit weird, but just more economical I suppose. I can now put 3 pod designs on a 10x10 PCB orderQuote from: UK on November 06, 2023, 03:36:03 pmTo flip the order? Yeah I was thinking that too, though it would also mean length matching traces again etc. And, having a MSB - LSB layout isn't that bad :pQuote from: UK on November 06, 2023, 03:36:03 pmYeah, I'll sleep on it some, though those connection points etc are all on those differential channels. This is now on the 'more anloguey' input. fair nuff, it's a digital input in the end, so an additional via won't hurt of course.So it would end up something (a little prettier) like this, length matching should be duable, I just don't like the fact that I have to use really thing traces now (0.25mm), because much more won't fit between those pins of course ...

author: ebastler
author_rank: Super Contributor
timestamp: November 06, 2023, 08:23:05 pm
content: Quote from: oliv3r on November 06, 2023, 07:47:35 pmThat should work. You can make the traces nearly twice as thick as they currently are and still keep the minimum distance from the pins, it seems.And you should not need much extra room for length matching in that area: Channels 0 and 3 have extra wiggles above the voltage dividers anyway; if you straighten those, the lengths should be reasonably well-matched already?

author: UK
author_rank: Regular Contributor
timestamp: November 06, 2023, 09:00:53 pm
content: Quote from: oliv3r on November 06, 2023, 07:47:35 pmI don't understand why you even need this since previously you told us you won't mass produce them... currently, every PCB manufacturing service offers a minimum 5pcs of PCB which is 4 pods + 1 extra... what a point to place 3 pcs on 1 PCB if you do not plan to get in total 15 podsQuote from: ebastler on November 06, 2023, 08:23:05 pmTotally agree!You can route them like this to get nearly perfect length matching.Edit: really forgot we have here 4 layer PCB

author: mwb1100
author_rank: Frequent Contributor
timestamp: November 06, 2023, 09:32:07 pm
content: A little bit of an interjection: I'm really a software guy so pretty much everything here is over my head, but I have been loving following this thread. Seeing the issues involved in designing a layout AND seeing the amazing collaboration going on here is just fantastic!

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 06, 2023, 09:46:52 pm
content: So while fiddling with it, it wasn't actually that hardand not even that ugly. I've put the traces all in the middle, so that a) ground planes help, and b) I did really need that room.Quote from: UK on November 06, 2023, 09:00:53 pmWell I also want some spare/give away's :p and .. options/premature optimization :p My OCD also won't cope going just a few mm over 5cm board sizeAs for mass-producing, if there's tons of people wanting these boards, I might order a bigger quantity of course, but I won't be going into business selling these, that's true.Quote from: UK on November 06, 2023, 09:00:53 pmYep, I played with it a bit, and got to 0.4mm which isn't too horrible I thought.The wiggles above the voltage dividers are needed, because the center two channels come from the top of the chip, so need to go all the way from the top, to the bottom.Quote from: mwb1100 on November 06, 2023, 09:32:07 pmSame here, I couldn't properly design this, I don't know enough about EE, but we got the reverse engineered pods and earlier designs, that I'm hopping will prove to be true :pIt's mostly just me taking other peoples great idea's and re-spinning them, listening to ebastler and UK for feedback/wishesP.S. I asked the admin/moderate to spin this thread into its own forum post, so lets see if that'll happen

author: ebastler
author_rank: Super Contributor
timestamp: November 06, 2023, 10:21:35 pm
content: Quote from: oliv3r on November 06, 2023, 09:46:52 pmNo, I don't think they are needed. They are in channels 0 and 3, right? And now you have created additional wiggles in channels 1 and 2 just above the 2*4 plug. They pretty much even out, so just do away with all four of them -- that's what I meant.Otherwise, great work, and I am excited to see the pod getting its final touches!

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 07, 2023, 07:30:58 am
content: Quote from: ebastler on November 06, 2023, 10:21:35 pmSo on the top-size, from the chip to the resistor/capacitor network, there's a wiggle to compensate for the length of channel 1 & 2 which come from the top of the chip, and run on the bottom side. So all traces from the chip, to the network are all 4 in identical length. The wiggles after the network, is to match the length of the outputs going to the 2x4.There is one thing that isn't properly matched though, just because I don't know how, and that's the length of the wires in the network, they should be the same but I wouldn't be supprised there's an error inthere, especially in the lm7234 pod, as the network isn't oriented identically, to make things fit better (0&3 and 1&2 are identical though). And since the parts aren't perfect tetris blocks (resistors and capacitor 2012's have different sized pads ... go figure.One tiny advantage of not putting the PCB underneath the connector btw, is that we can put in the connector a bit lower, allowing the pod to be not as fat. I even thought of doing the same as with the 50pin connector, and use an SMD layout, for a straight throughole part and side-mount it ... should fit?Does require clipping some sticking out legs though ...

author: ebastler
author_rank: Super Contributor
timestamp: November 07, 2023, 07:53:00 am
content: Quote from: oliv3r on November 07, 2023, 07:30:58 amI think we are still not talking about the same traces. Referring to the attached montage, I was looking at the length-matching wiggles indicated by the two smaller circles. They seem to be for channels 0 and 3. And now you have added the wiggles for channels 1 and 2, indicated by the larger circle. These four seem to be of very similar length -- so can't you simply remove all four of them?Edit -- some further, unrelated comments:I like the lowered position of the 2*4 connector; makes the vertical alignment nice and symmetrical.Don't forget to change the channel numbers on the top and bottom silkscreen to 0..3!Please correct the top silkscreen to sayLMH7324.

author: UK
author_rank: Regular Contributor
timestamp: November 07, 2023, 03:34:20 pm
content: Finally, guys, I found a solution for vertical 50p headers!Firstly, such headers are not rare at all, it’s just that most manufacturers do not mark them as elevated or extra tall.Secondly, there not many have in the lineup version 2x25.Even Pololu produce such headers already many years but only in 2x20 version.BUT if you try to search directly PC104long pin, you can get a ton of them, its Chinese OEM headers which are very widely available on many markets... amazon, ebay and of course most cheap prices onaliexpress. There exact option 2x25, but as a rescue option 2x5 also available (that may be staked in row by 5).The main interesting part is that its high may be easily raised just by adding a plastic part salved from common pin header (pic from Pololu nicely illustrate that).-------So now we have an all option for vertical 50p andvertical HDMI socketsAnd as for the vertical HDMI sockets looks like Rigol use C2682172 in their DHO scopes, you can cheek ithere... but I think C5204145 definitely more robust.-------PSQuote from: oliv3r on November 07, 2023, 07:30:58 amExtremely like the idea of low-ride 8p socket position!

author: ebastler
author_rank: Super Contributor
timestamp: November 07, 2023, 03:47:32 pm
content: Quote from: UK on November 07, 2023, 03:34:20 pmYes, these should work. They don't even need a spacer permanently installed, I think, since there are so many pins to keep them stable. But of course you need some spacer or alignment aid during soldering, to make sure you solder them in at the right height.These connectors do not have the little tab which ensures you can't plug them in the wrong way. So the PCB will need some clear lettering on the front to show the user which side is up.EDIT: Or rather, the 3D-printed enclosure will need to provide that lettering. Or one can try and glue a little plastic tab onto the connector which matches the notch on the scope side.

author: UK
author_rank: Regular Contributor
timestamp: November 07, 2023, 05:14:23 pm
content: Quote from: ebastler on November 07, 2023, 03:47:32 pmYep, it's definitely not a problem and it just could be a part of the shell.-------I've made a try to calculate the best dimensions for 2х2 PCB, which taking into account all shell clearances and possible margins, should have a perfect fit with both of the scopes!Also, I want to point out that 50p header should have a slight vertical offset.To be honest, now I'm even more interested in the version for DHO900 since I plan to get this cute little scope during the winter holidays

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 07, 2023, 09:56:48 pm
content: Quote from: ebastler on November 07, 2023, 07:53:00 amBut I think we areThe yellow lines are the same four lines for all four channels, that's why the wiggles exist before the input of the resistors and caps. You could probably do some math, and reduce the bottom wiggles from the top wiggles, I certainly grant you this, but it makes it harder to raid/verify/maintain. Now you have identical wherever they are measurable. Also, making it harder, and some wiggles still remain. Also, those 'ears' on the left/right side ... plenty of space for those anyway :p Also looks a little more symmetrical this wayQuote from: ebastler on November 07, 2023, 07:53:00 amcheck, check, check

author: ebastler
author_rank: Super Contributor
timestamp: November 07, 2023, 10:32:52 pm
content: Quote from: oliv3r on November 07, 2023, 09:56:48 pmAlright, I see. You prefer to match all four traces below the divider components, and then also match all traces between the divider and the LMH7324. It will certainly work; it just results in more wiggles on the board than needed. But maybe that's just an obsessive-compulsive thing for me...

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 07, 2023, 10:42:14 pm
content: Quote from: UK on November 07, 2023, 05:14:23 pmWhile I get the excitement for the vertical ports, ignoring for a moment that I used the wrong part :p, where in the world would we put the actual traces? I think even going full smd (which still requires the same amount of via's just for the holes to reach the other side, or go hybrid (smd HDMI connectors, throughole IDC connector (or vice versa) we still need a ton of via's just to route all those signals. I've also tried two options, one logical (1, 2, 3, 4) and one shortest trace (2, 1, 4, 3), which gives a rats-nest mess. What I did in the end, per your request, ordering the ports, was only possible by enlarging the PCB by half or full cm, which isn't really an option in this case?I'd route if if I had any hopes, but with these parts, it would require going with the tiniest pitch, and probably forget about doing length-matched traces ...

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 07, 2023, 10:43:41 pm
content: Quote from: ebastler on November 07, 2023, 10:32:52 pmHeh, my OCD says the same, but then I compromise, or convince myself, it's nicer, cleaner and more symmetric to have every measurable line matched in length. So you can pick any line on the pcb, and find its length matched trace. It just depends how you look at it I supposeTrust me, my OCD is itching with the thought, I just have to convince my OCD is better then your OCD

author: ebastler
author_rank: Super Contributor
timestamp: November 07, 2023, 11:27:07 pm
content: Quote from: oliv3r on November 07, 2023, 10:42:14 pmUmm, are you sure you have oriented the 2*25 connector the right way round? Isn't the notch, and also pin 1, facingupin the scope?If it really needs to be flipped around, that might give you a fighting chance at routing the PCB for a "logical" HDMI connector order. It will still be very tight, no doubt about that. I agree that switching to SMD-style HDMI connectors could help a bit. (The "brick nogging" type from LCSC; they would still have through-hole mounting tabs though, which are good for stability but get in the way on all layers.)Other degrees of freedom are rotating the HDMI connectors 180°, or moving them laterally a bit closer to the middle and moving the LEDs to the outside instead. Not sure whether either of these would help with the routing. The lateral move should at least give you a better symmetry of the trace lengths for the left vs. right connectors, requiring less overall trace length and wiggling.EDIT: I looked again at the pinout of the 2*25 connector. It looks like it ismirrored, rather than rotated? Pin 1 should be in the upper right, I believe. -- So D0..D3 and D8..D11 will be on the right-hand side of the connector. I would definitely place their HDMI connectors on the right side too; don't see a usability problem with that.

author: UK
author_rank: Regular Contributor
timestamp: November 07, 2023, 11:49:04 pm
content: Quote from: oliv3r on November 07, 2023, 10:42:14 pmSo we have another challenge here...the way it can be done is to implement all of that as a stack of two PCBs assembled by two rows of pins on their wide sides (in the style of Arduino Nano).Pros: doubling the space, separating PCB for HDMI sockets and 50p header, and as a result easier component placement and routing... and cons: 3-4mm additional stack height, doubling PCB cost and additional 10 mins for soldering pins during final assemblyMulti board PCB or multi level PCB is a very common practice when a complex PCB should be fitted in a very tight space.

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 08, 2023, 01:03:18 pm
content: Quote from: UK on November 07, 2023, 11:49:04 pm"But is it worth it", the mini-hdmi breakout board is already smaller afaikAlso, the IDC connector was also the wrong one, it was the female kind, but that flipping of the pins, is a triviality and won't affect the rats nest much

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 08, 2023, 01:04:00 pm
content: Quote from: Mechatrommer on November 08, 2023, 03:19:14 amI asked the admin to split of the thread, but no reply yet

author: UK
author_rank: Regular Contributor
timestamp: November 08, 2023, 01:43:04 pm
content: Quote from: oliv3r on November 08, 2023, 01:03:18 pmIt depends, if you want to have more fun - yes, if just finish this project asap - definitely notI've already started working on several mini HDMI board shells.

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 08, 2023, 03:02:14 pm
content: Quote from: oliv3r on November 08, 2023, 01:04:00 pm10 pages is still easy to handleand usually like all other threads, the first few pages are the most usefull one anyway, can ignore the rest. ymmv. cheers.

author: ebastler
author_rank: Super Contributor
timestamp: November 08, 2023, 03:17:13 pm
content: Quote from: Mechatrommer on November 08, 2023, 03:02:14 pmWell, in this particular thread the first 6 pages focus on a low-cost probe with limited capabilities (TTL/CMOS level only, fixed threshold). Towards the end of page 6, oliv3r presents his project which supports different flavors of probes -- either using the same low-cost TTL/CMOS driver, or using the proper (but expensive) comparators and 10:1 divider front-ends as used in the original Rigol probe.That might make the overall thread a bit hard to follow; and for the second part one could argue that the thread title is a bit misleading. Also, it would be nice to get the DHO900 mentioned in the thread title, since that new scope uses the same logic probes as the MSO5000.

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 08, 2023, 04:16:33 pm
content: Quote from: Mechatrommer on November 08, 2023, 03:02:14 pmProblem is, that this has absolutly no relation to easyeda anymoreand I really just hijacked the thread, which isn't nice :p

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 08, 2023, 04:21:54 pm
content: So I ran into one little bit of an issue, the 497 resistor doesn't seem to exist ... I know that the original drawing is reverseengineered and 'measured'. But then I also don't understand the original/intended design (at all) to see what is a good fit replacement.So for now, I'm going with 499Ohm, which does exist, which is 'close enough', and also fits in the E96 list, so not unlogical to have been used. Same for the 90k8, which will become a 90k9

author: ebastler
author_rank: Super Contributor
timestamp: November 08, 2023, 04:36:28 pm
content: Quote from: oliv3r on November 08, 2023, 04:21:54 pmSure, neither of these should be highly critical, and especially the 49x Ohm resistor is not.The 90kx resistor forms a 10:1 voltage divider together with the 10k resistor, so the "perfect" value would be 90k0. But who cares about a 1% error in the divider ratio?The 49x resistor in series with the 3.3pF capacitor forms a bypass for high frequencies. I.e. they will not be attenuated by 10:1 but much less; presumably to preserve exact timing of the signal edges. But I don't see why you couldn't even be 10% off here without creating a problem. (The capacitor will have at least a few % tolerance anyway, so your RC time constant won't be that well-defined.)

author: oliv3r
author_rank: Frequent Contributor
timestamp: November 08, 2023, 05:00:58 pm
content: Quote from: ebastler on November 08, 2023, 03:17:13 pmWell that's also part of the reason I went with quad pods, to lower the cost of the probe, not often you need 16 * expensive partsthe quad vs dual LMH's is a cost/availability/performance/original thing. We'd want to have 1 pod that's next to identical of the original, and LMH7324's that might be cheaper/but maybe hotter? Who knows why rigol did what they did

author: UK
author_rank: Regular Contributor
timestamp: November 16, 2023, 08:20:36 pm
content: Thanks to @sergk for themeasurementsof the DHO900's LA slot... can say with confidence that it's absolutely the same as on MSO5000.Almost finished the shell for the mini-HDMI board, but the PCB will definitely require some edits for adding several slots and holes for the screws.@oliv3r, did you already order the PCBs?

author: rdtsc
author_rank: Newbie
timestamp: November 22, 2023, 03:44:32 pm
content: If this is to be believed,Esalercurrently has 942pcs of the LMH7324SQX/NOPB for $0.92ea.

author: UK
author_rank: Regular Contributor
timestamp: November 25, 2023, 12:33:50 am
content: Here is the finished shell foroliv3r's breakout board, firstly, it was a bit tricky to make HDMI sockets look visually vertical and LEDs visible from any angle... secondly, to make a proper shadow line with a safe 1mm margin to the LA slot inner walls and find a good place to securely fasten the shell to the board. It prints really well, you can check a closeup photo, where it was printed out in matte black PLA with a standard 0.4mm nozzle and 0.16 layer height.Really hope oliv3r will publish the final version of its board soon and I won’t have to recreate it from scratch.Quote from: UK on November 16, 2023, 08:20:36 pm@oliv3r pls, check the board outline in the attachment. PCB requires small edits.

author: ebastler
author_rank: Super Contributor
timestamp: November 25, 2023, 07:02:00 am
content: Wow, that looks very cool indeed! Very nice job!I'm curious: What software are you using to design and to produce those stunning renderings? (Which even include the layer structure of the 3D printer apparently, so the software seems to know about the slicing too?)

author: UK
author_rank: Regular Contributor
timestamp: December 01, 2023, 06:15:28 am
content: Freeze! Forum police here!

author: ebastler
author_rank: Super Contributor
timestamp: December 01, 2023, 09:51:31 am
content: Quote from: Tarloth on December 01, 2023, 05:42:23 amNext time you might want to ask ChatGPT to word your message. It tends to get the tone about right.Yes, this discussion of a "proper", comparator-based logic probe has become bigger than Oliver originally expected. So what do you propose we do about it? Users cannot move parts of a thread to a new one; Oliver asked the moderators but they did not get around to it, or did not consider it worthwhile. So what?As threads on this forum go, I think the past pages have been one of the more productive examples. Something actually gets developed, in a joint effort, with feedback on improvement ideas. Much better than the haggling we get in some other threads. And yes, the connector discussion is highly relevant in this context. Guess what? Using a standard ribbon cable with 50 conductors to the probe sucks.If you are interested in the cheap solution, since all you want to probe is 5V and 3.3V logic: Buy a complete LA probe on ebay for $75 including cheap grabbers; problem solved.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 01, 2023, 04:44:48 pm
content: as long as discussion circling around somewhat evolution or improvement to the probe, i'm fine... btw, is there any clear diagram rev eng people made about what every single pin does on the MSO5000's 2x25 2.54mm pitch LA connection? (i guess should be the same/compatible with DHO900) all i've seen so far are finished diy probe product... what if i want to make my own LA probe? if there is diagram, i dont have to redo rev eng...

author: ebastler
author_rank: Super Contributor
timestamp: December 01, 2023, 04:56:09 pm
content: Quote from: Mechatrommer on December 01, 2023, 04:44:48 pmSee below, for example. And yes, it's the exact same pinout on the MSO5000 and DHO900. (The DS1000Z plus has a slightly different connector. Same signals, but more GND pins and hence 68 pins in total, I believe.)https://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/msg2419002/#msg2419002EDIT: If you want to design your own probe, don't talk about it here or Tarloth will get mad at you...

author: Simon
author_rank: Unknown
timestamp: December 01, 2023, 08:31:20 pm
content: If you can find me a thread that 10 pages in has stuck band on topic I will devise a medal for you!

author: ebastler
author_rank: Super Contributor
timestamp: December 01, 2023, 09:07:41 pm
content: @Tarloth -- you come into this thread complaining and shouting at us, then you follow up with two dissertations. You still have not answered my question in response to your initial complaint: What do you expect Oliver, UK or me to do with this thread now? Delete all our posts?

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 02, 2023, 10:03:29 am
content: can someone re-explain how 49.9ohm and 220ohm resistors form 1/10X attenuation? i read the original rigol la probe limit is 40V, 1k ohm input impedance? this is mind boggling.i'm referring to this post:https://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/msg2088667/#msg2088667

author: ebastler
author_rank: Super Contributor
timestamp: December 02, 2023, 10:13:03 am
content: Quote from: Mechatrommer on December 02, 2023, 10:03:29 amYou need to look at theinputside of the comparator, with a 10k/(90.8k+10k) divider. You were looking at the termination resistors for the differential output.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 02, 2023, 11:12:16 am
content: Quote from: ebastler on December 02, 2023, 10:13:03 ami thought the bottom side is the input, no? so that means, top side is the input?

author: ebastler
author_rank: Super Contributor
timestamp: December 02, 2023, 11:33:39 am
content: Quote from: Mechatrommer on December 02, 2023, 11:12:16 amIn the schematic in the post you linked to, the inputs are on theleftside of the comparator: The probed signal on IN+, the reference level (threshold) on IN-. The relevant voltage divider is on the IN+ signal.The resistors you talked about (49 Ohm and 220 Ohm) are shown on therightside of the comparator. That's where the two differential output lines are. The resistors donotform a voltage divider; these are termination resistors.Are you sure you should be considering your own probe design?EDIT: Ah, you were now talking about the photo? Better use the schematic if you want to study the circuit design... But yes, on the photo the differentialoutputsare on the bottom -- which is why there are twice as many connections.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 02, 2023, 12:46:28 pm
content: Quote from: ebastler on December 02, 2023, 11:33:39 ami'm currently trying to understand this thing inside out while i have time and interest. including evaluating pre-existing diy and original design how and why they do it.. just now trying to find comparator replacement to unobtanium LMH7322 (LMH7324 also not available from the sources i usually buy things from), not an easy task.. currently listing as possible/cheaper replacement ACDMP 607/562/564/567 but they are equally hard to find or expensive. LT1715 is cheaper, but probably crippled and 4ns prog delay may put some people off. what i dislike about pre existing is their form factor, large IDE connectors here and there and right angle connection, i prefer if possible much compact version with nice 3d printed casing... so i'm still evaluating, no conclusion yet, just learning.Quote from: ebastler on December 02, 2023, 11:33:39 amah sorry i didnt notice there is diagram attached below that post. thanks.

author: ebastler
author_rank: Super Contributor
timestamp: December 02, 2023, 12:51:24 pm
content: Quote from: Mechatrommer on December 02, 2023, 12:46:28 pmI doubt you will find anything compatible and cheaper. They are available from e.g. Mouser and Digikey, aren't they?Make sure to look not only at the input specs (levels & speed), but also at the differential outputs. You need RSPECL (Reduced Swing Positive Emitter Coupled Logic) outputs to make your scope happy.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 02, 2023, 01:05:00 pm
content: Quote from: ebastler on December 02, 2023, 12:51:24 pmi'll try to find cheapest source i can get first, even from aliexpress 8pcs ADCMP576 alone will cost me $69, mouser and digikey will cost much more damage to my place guaranteed. 10pcs LT1715 is $37 though, but not look deeper on suitability. if no cheaper option, or if its not worth the effort to redesign, then i might just get the $75 probe from ebay, but then not sure what ic it is using. no prog delay spec no BW no nothing, so its shady.Quote from: ebastler on December 02, 2023, 12:51:24 pmnot sure about this yet, limited reading resources. but isnt LA input (comparator output) directly connected to DHO FPGA? ie just logic input 0 and 1? as long as within voltage limit range it should be ok, no?

author: ebastler
author_rank: Super Contributor
timestamp: December 02, 2023, 01:40:11 pm
content: Quote from: Mechatrommer on December 02, 2023, 01:05:00 pmThe low-cost probes do not use comparators with an adjustable threshold, but simpler LVDS drivers -- SN65LVDS1DBVR or similar multi-gate parts. You might be able to spot on the ebay photos what has actually been populated.QuoteThe FPGA inputs are configured for LVDS (low-voltage differential signaling), and the comparator voltages are chosen such that the RSPECL outputs are compatible with that. Youwillneed differential outputs on the comparator; they could be LVDS instead of RSPECL, I guess.The LT1715 you mentioned does not have differential outputs, and its output voltage might damage the FPGA's LVDS inputs? LVDS logic levels are only 1.0V and 1.4V; not sure what the FPGA can tolerate as absolute maximum ratings.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 02, 2023, 02:05:13 pm
content: Quote from: ebastler on December 02, 2023, 01:40:11 pmyes noted with concern, thanks for the info... while working on another section of dho, i got stucked since some parts havent arrived yet so i start doing reading on LA section, and i managed to pop something out of my fw hacked dho804 with help from diagram you provided earlier, without needing to flow solder the 2x DDR3L RAM in, so there's interesting hope. interestingly, sampling rate and memory depth not reduced so bad when this got activated as somebody else reported/portrayed much earlier. only halved and thats not too bad, its normal imho. 625MSps still can debug 300MHz 16ch logic, yes?ps: i guess low cost probe for DHO800/900 and discussions should not be posted here right? otherwise police will tantrum?i prefer to call "advisor" because advisor we can ignore, police if we ignore, we will go to jail, or got banned and cannot post in forum anymore. i sometime will become nonsense advisor myself

author: ebastler
author_rank: Super Contributor
timestamp: December 02, 2023, 02:17:59 pm
content: Quote from: Mechatrommer on December 02, 2023, 02:05:13 pmBe careful when probing around and making connections across the 50-pin connector! There are definitely voltages there which the LVDS inputs won't like, including negative voltages.The 625 MHz sampling rate for the LA is as expected, and I agree that it is adequate. A bit inconvenient maybe that it's such an odd number. The remaining 625 MHz for a single analog channel, or only 156 MHz when using 3 or 4 analog channels, are the disappointing part. (And the part which is not "normal" -- the analog sampling rate in MSOs is typically limited by the ADC, and does not get reduced when digital channels are activated.)That AWG board looks promising!But yes, let's be good boys and move this scope-specific discussion to the DHO800 hacking thread.

author: UK
author_rank: Regular Contributor
timestamp: December 02, 2023, 02:23:24 pm
content: Quote from: Mechatrommer on December 02, 2023, 02:05:13 pmA new thread will be better since many new users come here for the DHO800/900 series. They won’t think to look for information in the MSO5000 threads and may easily miss it.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 02, 2023, 02:35:21 pm
content: Quote from: ebastler on December 02, 2023, 02:17:59 pmthanks to the diagram you provided. made some probing earlier, i believe whats missing is 4V rail. but i got MPM3630 already in case i need it.Quote from: UK on December 02, 2023, 02:23:24 pmagreed. i'll make another new sub thread when something practical achieved.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 05, 2023, 10:59:17 pm
content: Quote from: Tarloth on December 05, 2023, 07:51:41 pmwhich one of my post is not about low cost probe?

author: UK
author_rank: Regular Contributor
timestamp: December 06, 2023, 09:12:03 am
content: I assume he just saw a 'DHO800/900' model name in the thread of the MSO5000 probe.Hope this dude never gets any sort of gun or police badge in real life.I'm a bit nervous when he starts writing in all caps.

author: ebastler
author_rank: Super Contributor
timestamp: December 06, 2023, 09:28:01 am
content: Quote from: UK on December 06, 2023, 09:12:03 amFortunately this forum software does not offer the functionality to send a proper Howler.

author: oliv3r
author_rank: Frequent Contributor
timestamp: December 08, 2023, 02:50:51 am
content: Quote from: UK on November 16, 2023, 08:20:36 pmI did not, I've been simmering on a different board, so that I can review it with fresh eyes, and new insightsSo what changes are you thinking of?Quote from: UK on November 16, 2023, 08:20:36 pmYeah, I got distracted a bit; I will certainly publish everything, nothing to be recreated.I see you added 3 screws, I wonder if there's room for them, and _need_.Though those 3D renders, so sexy!!Quote from: UK on November 16, 2023, 08:20:36 pmSo, this raises a few questions. Do we really need 5 screws? can we do with just one in the 3 (1 in the middle)? They all go through traces :p and in the middle, it's not an issue, I can change the trace, but the outer two traces go between some caps/resistors, rerouting that is a little trickier. I've added a 2.2mm hole (smallest kicad footprint is 2.1 but want to leave room fro the threads?) and it looks like this. Might prefer to get the trace slightly further away from the shield hole though ... shouldn't be an issue?Also, do we need to cut away so much from the connector side? I don't mind doing it, but the connector itself is much wider then the PCB (see attachment)Quote from: Tarloth on December 01, 2023, 05:42:23 amFirst of all, I have requested to split off the forum 2 times, but nothing has happened. Others mentioned this as well. If you manage to pull this off, it is much appreciated.Secondly, The topic is about a low-cost alternative. This is a low-cost alternative. It's just not in easyeda, but that's not a froum crime is it? One of the LAPOD's follows the exact same principle as the original ...So we are respecting the original thread, we are improving on the original design and adding more LAPOD'sBut again, instead of complaining and derailing the thread about not- LA's, get the forum split. Please. We tried.BtwQuote from: Tarloth on December 01, 2023, 05:42:23 amwhat do you think pod_sn65lvds is?edit: Did the changes already, was easy and doesn't look too bad. Just need to discuss the extra 2 holes :p nvm, got the holes in, not sure about the clearance, but DRC is not complaining ...

author: oliv3r
author_rank: Frequent Contributor
timestamp: January 24, 2024, 09:44:40 pm
content: Great news everyone!It's been 6 long long weeks, and it's not all there yet, BUT! I've finally gotten my CI/CD pipeline where I want it to beHad to get a few bugs fixed, features added etc to KiBot (Thanks Salvadore!!) but the results are pretty cool.The repistory is right here,https://gitlab.com/riglol/lapodbut only the breakout boards for now. I'm still wrapping up the pods (getting the LCSC part numbers in etc, getting rid of the ERC and DRC errors (or ignoring them where needed). The first pod is nearly done, so I'll hopefully push that tomorrow.The MR where I'm doing my work is right herehttps://gitlab.com/riglol/lapod/-/merge_requests/1and the pipeline has all the outputshttps://gitlab.com/riglol/lapod/-/jobs/6004605746/artifacts/browse, such as this nicely blender rendered mugshot! (Should have used that as name instead of `front` ... :p).There's also a ton of other files there, such as step files, vrml files and what not.The connector is a bit crooked, that's a bug in blender that'll get fixed in the next big release in march, so until then, that's what it is. Also, I hope that we get a better lightening engine with kibot's blender run soon! There's also the kicad generated render, which looks a little better in some other ways.Be aware, that the job artifacts expire in a week, which is good, as this is all a little WIP. Once I merge and tag the MR, the artifacts should stay forever of course.The kicad files are also included as expectedit is open source after all.So ... in case you didn't miss me, I did think of ya'llNow if we could only get Dave to split the thread ...

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 26, 2024, 09:07:01 am
content: Comradesebastlerandoliv3r, you have filled half the pages of the topic with personal communication with not very related topics. Got carried away.This is usually called a flood in forums.I do not know how to highlight your communication and move it to a separate topic, is there such a forum opportunity.It is possible that a moderator will do this, but not necessarily.So don't go on, please. Create a new separate topic and put a link to it here so that those interested do not lose the thread of your discussion.

author: ebastler
author_rank: Super Contributor
timestamp: January 26, 2024, 09:31:44 am
content: Quote from: S. Petrukhin on January 26, 2024, 09:07:01 amYou might have noticed thatall our discussion was about a low-cost probe for the MSO5000 (and DHO900), so fully on-topic, andoliv3r has asked the admins multiple times to split the discussion about his particular implementation out into a separate thread.So I can't understand what problem you have with oliv3r and me. And I don't accept your attempts to police us.

author: ebastler
author_rank: Super Contributor
timestamp: January 26, 2024, 09:59:55 am
content: I don't think there is such a thing as a "thread owner".It's fine with me to have the discussion about oliv3r's design split out into a separate thread; as mentioned, oliv3r has asked for it several times. But starting a fresh thread and losing all the history is not desirable. And I strongly object to the way S. Petrukhin framed his request -- describing this as a personal off-topic discussion by two people, which is wrong on multiple levels.Anyway, I'm out of here since I will not get a Rigol scope which supports this probe. Nevertheless, I hope oliv3r's design gets finalized, since it is better as well as lower cost than the original Rigol probe.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 26, 2024, 10:01:32 am
content: Quote from: ebastler on January 26, 2024, 09:31:44 amI have no desire or ability to control.You have created a different product, a different solution and discussing it. Same people have told you about this.It is a good tone and respectful attitude to the forum users - create a separate topic and post a link to it here.There are several different options created already and their authors have done just that.This is my request.Moreover, popularity of Rigol 5xxxx is greatly decreasing and growing for 9xxx - topic with 9xxx name will be useful to other users.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 26, 2024, 10:09:37 am
content: When you create a new topic with a new solution, a new discussion will appear - I assure you.And you can post a link to the beginning of the discussion here in the new topic - everything is very simple.There will be confusion in this topic and it is often unclear for which option the question arose.

author: oliv3r
author_rank: Frequent Contributor
timestamp: January 26, 2024, 10:12:10 am
content: If more people can spam the admin (dave) that'd be great, I've sent him several messages. Maybe I'll create a new thread, just for dave. I have been reluctant to create a new thread, exactly because I don't want to loose the history. It's to important. Should I have started with a different thread? Maybe. At the time, it was just a remix with different connector between the pods .... Your name is even in the schematic as creditsAlso, there was discussion going on in this thread about 'other low cost logic analyzer probes' and this seemed to be 'the home' for alternative probe options.Anyway, here's the support request thread:https://www.eevblog.com/forum/news/help-in-splitting-topic/new/#newCreating a new thread and link to the specific post also is painful, as the 'search thread' feature does not work anymore.Without further ado however, here's the podsI've got them in the pipeline now too. Took some fiddling to fix some erc and drc errors, filed some kicad feature requests, but here are the artifactshttps://gitlab.com/riglol/lapod/-/jobs/6025346734/artifacts/browseWhat's left to do, is add a nice README of course, and clean up the 'fab' layers. I've 'hidden' them up until now, as they where just annoying. But I'll clean those up too; just because.The 'component' I've created, will have to be upgraded as well, to deal 'releases' so that the artifacts don't die after a week. Note that this is intentional, as storage costs money, and using storage for 'draft' files is not cool. Also, re-running the pipeline recreates them easily.Here's the front blender renders of all partsP.S. Nice to see you back S. PetrukhinP.P.S. Hopefully UK will pick this up and start doing some amazing 3D cases again :p

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 26, 2024, 10:31:51 am
content: Quote from: oliv3r on January 26, 2024, 10:12:10 amIt doesn't matter what my name is.I made a primitive construction, it costs nothing.Anyone can use it at their discretion without contacting me, including for commercial purposes.I don't understand your tenacity.Maybe you have little experience and do not yet know the traditions and respectful attitude - I don't know.But demonstrating this and showing lack of culture is not the best option.You're just losing the interest of 9xxx series users. They will most likely don't come to this topic.

author: oliv3r
author_rank: Frequent Contributor
timestamp: January 26, 2024, 10:39:05 am
content: Quote from: S. Petrukhin on January 26, 2024, 10:31:51 amWe still need a 9xxx breakout board, which requires a pinoutYou could also change the topic to 'MSO5k & DSO9k projects' and spark interest. OR, rename the project that it is specific only for YOUR design, and then clean out all other off-topic discussionsAnd I asked the admin to split the thread, multiple times, but I don't want to loose the discussion happening, it's too valueable. My hope is still, to get the admin to split the forum. Just needs some attention from the admin, it's only a button press after all.

author: ebastler
author_rank: Super Contributor
timestamp: January 26, 2024, 10:43:41 am
content: Quote from: S. Petrukhin on January 26, 2024, 10:31:51 amCome on, man. Oliv3r and I have been around here longer than you. Why would you think you are entitled to teach us about forum traditions and culture?On a loosely related note: Maybe you should reconsider your choice of forum avatar. I know it's just a picture -- but being lectured by a deranged-looking little guy who is waving his arms at me like an ape does in fact irritate me, and taints the reception of your posts.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 26, 2024, 10:52:17 am
content: Quote from: ebastler on January 26, 2024, 10:43:41 amI'm sorry, I have no desire to talk about nonsense and respond to conclusions about the number of messages.Obviously, this is not the only forum where my posts are. It's weird...

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 26, 2024, 11:05:45 am
content: Quote from: oliv3r on January 26, 2024, 10:39:05 amThe author of the topic on this forum does not have the ability to delete messages, no additional permissions.If there was such an opportunity, I would not delete - it is bad and insulting for users.Moderators may not interfere here, providing the maximum possible freedom.I would suggest that you, nevertheless, create a new topic and insert a link to the beginning of the discussion in this topic in the first message.It's a common case of "we moved from here: <message link>".

author: oliv3r
author_rank: Frequent Contributor
timestamp: January 26, 2024, 02:25:11 pm
content: We could start fighting here, so that dave comes in and splits the threadBTW, you can edit the subject of the first message in a thread, which is also the thread topicOr, we can just ignore all the bickering and focus on the part discussion at hand. So feel free to do some reviewing of the schematics/pcb/bomOnce I've got a 'v1.0' and we don't have a split thread, I surely will create a new thread, as the history is less relevant then.

author: oliv3r
author_rank: Frequent Contributor
timestamp: February 01, 2024, 05:48:53 pm
content: I just did a Paper print, just to see how it would fit int he scope. Depending on how much room the case would consume on the sides, the second output is 'close' but not too close. I think there's about a cm between the bnc connector (with the plastic cap on) and the paper edge of the PCB.As for the HDMi connectors, The cheap ones I got 50 cm with quite fat shrouds around the connector, leave about 1.5mm (bare eye measurement) of space between each connector. I don't really want to get them closer together then that, which means, I won't have more space around the edges either to narrow the footprint. Of course this isn't a problem for the mini-hdmi variantI'lll leave the DSO7000 and DS1074Z out for the time being, as I don't think we have a verified pinout for either? (Though the DS1074Z might be available already? idk. Doing the pcb design is easy, but I don't have either so ...I'll let this linger for a bit for people to look at. I've attached the pdf's of the boards, which probably makes for easier review.Oh, the pipelines are 'done' in that I would be able tag and release the designs and get permanent outputs. I'll merge and tag the results next week, just after the artifacts expire. I won't be sending the gerbers of to the fab just yet, as I need to finish a few other boards too, but I'll start that new thread next week that people are so anxious about :pAnyways, have a good weekend already

author: oliv3r
author_rank: Frequent Contributor
timestamp: February 01, 2024, 05:52:23 pm
content: Oh, lets do some render pr0n too :p (which I couldn't do in the previous post; 10 attachment limit :S)

author: S. Petrukhin
author_rank: Super Contributor
timestamp: February 02, 2024, 09:39:35 am
content: Congratulations! I have added a link to the separated topics.

author: oliv3r
author_rank: Frequent Contributor
timestamp: February 03, 2024, 03:25:30 pm
content: I've done a small tweaks to the files, rotated the pods, so they fit better on paper, switched to kibot 1.6.4 for the pipeline, bunch of erc/drc errors I overlooked. Things are looking really good now. I'll merge this to master, and tag the first release candidate so I can get some PCB's ordered.Hopefully UK comes along again with some cool 3D designs for the housingsI do have to still do a few other PCB's (wanna do one big LCSC order for parts, and need some parts for measurements before ordering PCB's. OTH, they are so cheap, might just order the PCB's anyway ... we'll see.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: February 03, 2024, 08:01:32 pm
content: My humble opinion about using HDMI connectors.They are very bulky and, if you use industrial cables, they are heavy.As a result, we get a large and solid lever on the adapter in the sight to break and pull it out. It may be accidental.Perhaps Mini-HDMI is more convenient.But why use HDMI if LVDS works great on a simple flat cable?After all, the main idea of the probe is to convert a direct signal for transmission over a well-stable differential pair.If you wanted to divide the 16 inputs into parts, which is reasonable, then flat cables of smaller width and IDC connectors would be quite practical.And yet, maybe you didn't notice, but the guys at Rigol didn't care about the equal length of the conductors and even put LVDS terninators on the wrong side in the probe, and not in the scope - they discussed it. But it works.The minuscule differences that arise are very far beyond the scope resolution.You will get a greater impact from the capacity of connecting the probe to the circuit under study.We have a proverb: the skin is not worth the dressing. No matter how beautiful your shoes are, they will get dirty on a dirty road.

author: oliv3r
author_rank: Frequent Contributor
timestamp: February 03, 2024, 10:16:39 pm
content: Thanks for your feedback! It is much appreciated :pQuote from: S. Petrukhin on February 03, 2024, 08:01:32 pmIndeed, which is why there is the mini-HDMI variant. But getting mini-hdmi - mini-hdmi cables is probably very expensive/hard to get. I was thinking of even using micro-hdmi, but those connectors are very hard to properly route, due to the pin-pitch, and also don't have through-hole mechnical bits, to keep them in place.But not sure if I get your thing on 'industrial HDMI connectors'. Why? Nobody is using industrial IDC connectors on any of the pod designs?So 'normal' HDMI cables are not so bulky, are cheap and are shielded. But a simple flatcable is enough! Yes it is. The fact that they are shielded is a bonus, not a requirement. What other common, reusable connectors do we have? The thought of using IDE connectors even crossed my mind :p but 40/80 pins is too much, and who has those stillQuote from: S. Petrukhin on February 03, 2024, 08:01:32 pmSure, but now you have a cable designed for this. isn't HDMI "just LVDS" signal as well? If LVDS is so amazing, why is HDMI shielded? And again, what other convinient connectors do we have? USB-C is an option, but the reversibility is actually at your disadvantage here imo. And lets be fair, the IDC connector is really just butt-uglyBut sure, I could have gone with those flat cable 'serial' IDC connectors (x4). But still a bigger pain to deal with for a lot of 'slightly less DYI' peopleQuote from: S. Petrukhin on February 03, 2024, 08:01:32 pmYeah but I also don't like the 'robustness' of these flatcables. They are a bit too flappy. I'm sure they'll hold for years of course.And yet, maybe you didn't notice, but the guys at Rigol didn't care about the equal length of the conductors and even put LVDS terninators on the wrong side in the probe, and not in the scope - they discussed it. But it works.The minuscule differences that arise are very far beyond the scope resolution.I'm fully aware. Also, the traces inside the scope ARE length matchedwhat I saw in the x-rays anyway. So whoever did the probes didn't care, wasn't aware. And indeed, the difference is miniscule. But, if you build something, build it with pride. Doing length-matched traces was a fun excersize. Sure it was frustrating at times. But it's a labor of love after allMight as well polish it a little bit. It's not unheard of to over engineer thingsand it doesn't cost anything extra.Quote from: S. Petrukhin on February 03, 2024, 08:01:32 pmYou can keep polishing a turd, but it will never become shinyJust kidding, we pride ourselves in what we do, do we not?

author: S. Petrukhin
author_rank: Super Contributor
timestamp: February 04, 2024, 10:32:57 am
content: I've never studied HDMI standard, I don't know if it uses LVDS.But I didn't see any soft cables.When you receive the finished device, show a photo and share your opinion on how the 4 plugs in the adapter behave.The IDC with clamps is very reliable and the 6 cores of a flat cable can be very flexible, especially in 500mil step.You could look at RJ11 as an add-on. But it will take 16 of them...For training and pride in work, this is an argument.

author: jsobell
author_rank: Contributor
timestamp: February 18, 2024, 08:54:14 am
content: I like the look of the design, although finding some of these components is a real pain!Quick question, in the SN65LVDS pod, why are EN and /EN both held high at 3.3V?J.Edit:I see why. Your design is for the SN65LVDS391and not the SN65LVDS047version.

author: jsobell
author_rank: Contributor
timestamp: February 19, 2024, 08:11:04 am
content: Actually, the KiCad part in the schematic is wrong. It should be SN65LVDS391, and not the SN65LVDS047W in the diagram.The 047W is a 5V part with different pinout.LCSC don't have any (surprise!) but if you use the SN65LVDS047W then I guess you can do the old -2.2V trick to get over 5V, but you'll also have to fix pin 8, as it won't work if it's high.Cheers,Jason

author: oliv3r
author_rank: Frequent Contributor
timestamp: February 22, 2024, 10:16:12 pm
content: Thanks for looking into this! I think I also see the error of my waysI took the kicad build in symbol for the quad SN65LVDS, because it was much prettier drawn. As you stated, it is a different part!! SN65LVDS047PW which is not what I intended. I wanted it to be the SN65LVDS31D (but have to tripple check that now too) as you rightfully stated! I'll use the ugly symbol from lcsc for the actual part, and draw it prettier instead.Thank you! This is golden feedback and saved me a lot of agony!As for parts availability, those TI parts where a problem ever since the component shortages. digikey/mouser should have better availability I've been told. But I prefer to at least put all BOM parts as LCSC parts for now. Don't thin it's useful to use internal part number for each vendorAs for tying both EN and !EN to 3v3, the datsheet has a truth table, where it states that if EN is high, !EN is a 'irrelevant', and I wanted the pin to be a well defined value and not floating. But on second thought, might as well tie it to GND instead.

author: oliv3r
author_rank: Frequent Contributor
timestamp: February 24, 2024, 02:14:59 pm
content: So,https://climbers.net/sbc/clone-pla2216-logic-probe-analyzer/is where I got the sn65lvds idea from. The only 'problem' is the termination resistors. Which now sit close to the sender, rather then the receiver. But we can't put them near the receiver for obvious reasons.What's confusing me right now, is that Nikki's pinout of the SN65LVDS doesn't match what's in the datasheet. His pinout is much 'easier' to use, all diff pairs on one side ...C354139 is the SN65LVDS391PWR, TSSOP with a nicer pinout. C3239334 is the one I've used, SN65LVDS31D, with the alternating pinout. So .. I'll do it again, this time with the right partSo I've reworked it, but didn't do the whole '2 footprints' solution. A, because it makes routing harder, and B, hopefully the shortage issue is less of a problem.Besides, doing a SOIC variant of the PCB is always an option.

author: oliv3r
author_rank: Frequent Contributor
timestamp: February 25, 2024, 10:46:52 pm
content: So this is how it looks now with the proper chipthough just spotted my gnd fill not looping around my mounting holes on the left, so gotta check that out now too

author: jsobell
author_rank: Contributor
timestamp: February 27, 2024, 06:09:21 am
content: Quote from: oliv3r on February 22, 2024, 10:16:12 pmAh yes, I thought it was an XOR, but it's just an OR gate with an inverter on one leg. Yes, I'd tie it down too, as they do specify that all unused enable lines should be tied to VCC or GND as appropriate.Have you made one of these yet? I'd be very interested to see one.My only additional feedback is that I would use a very short ribbon cable to the initial pod, as I don't trust the front not to get knocked or pulled, particularly with four HDMI cables hanging off it.The 924 model has a constructed socket with the case plastic supporting it, but the 800 self-mutilated models look more fragile as there's no additional plastic supporting the socket soldered to the main board.Having said that, in my setup the direct plug would probably be more manageable as it's on a VESA mount.

author: oliv3r
author_rank: Frequent Contributor
timestamp: March 03, 2024, 11:10:24 am
content: Quote from: jsobell on February 27, 2024, 06:09:21 amI did change it to tie them better, but also the proper chip only has a single enable pin for channels 1 & 2, and a single pin for 3 & 4. So your observation was sharp and proper, not relevant after using the correct chipQuote from: jsobell on February 27, 2024, 06:09:21 amMe too :pNot yet, I am in the 'review' process right now, where I'm accumulating feedback (whilst also finishing up some other PCB's so I have one big JLCPCB order to do, because of shipping). WIth hardware, it's better to wait a bit longer and get some valued input, as that of yours. While iterating is of course cheap, Multiple eyes help more of course.Quote from: jsobell on February 27, 2024, 06:09:21 amThat is most certainly a possibility. But I leave that up to the user/builder. It's not like this is a product I'll be shipping. But one could use a male header instead of a female header on the breakout board, and connect it via a ribbon cable. Or just solder a ribbon cable. Or use a female -> male ribbon cable. The options are certainly there. I'm not sure yet on the wait issue, but the scope's female connector should be able to handle the weight quite well imo.Quote from: jsobell on February 27, 2024, 06:09:21 amI wish my scope had a VESA mount

author: jsobell
author_rank: Contributor
timestamp: April 06, 2024, 09:58:00 pm
content: Your schematic shows a TLV74325PDBVR regulator, but that's a 2.5V output and the SN65LVDS391PWR requires a minimum of 3V, so I suspect it should be a TLV74333PDBVR.

author: jsobell
author_rank: Contributor
timestamp: April 06, 2024, 10:15:47 pm
content: Ah, I see you've already patched it in the repo

author: Electro Fan
author_rank: Super Contributor
timestamp: April 08, 2024, 03:43:44 am
content: Quote from: oliv3r on March 03, 2024, 11:10:24 amLOLoliv3r you do great work

author: Songhua
author_rank: Contributor
timestamp: June 08, 2024, 10:59:01 am
content: Now it's June 2024, have you made one?Expect to see a real-working one.

author: maxora
author_rank: Newbie
timestamp: August 14, 2024, 03:50:18 pm
content: Hi Guys,So I made the thing. (POD_LMH7324andMini_HDMI_Breakout)I ordered the PCBs and parts, and soldered by hand.Checked for any dry joints or bridges. Didn't find any issues.However, when I connected the probe to the scope, it did not work at all. I also noticed that the LMH7324 is getting hot.So I started checking the connections and noticed that some pins are shorting out only when the HDMI cable is plugged to both PCBs.To narrow-down the issue, I connected a HDMI header and a mini HDMI header (not soldered to the PCBs) and started checking the connections between two ends.And that's when I noticed that thepins of the mini HDMI connector (Type C) are not in the same order as the HDMI connector (Type A).But in the mini_hdmi_breakout PCB, the pins are in the same order as the Type-A header.(The cable I used is a high speed HDMI cable with Ethernet)I think someone else also should test the pin connections and confirm this. (just to make sure...)And this is the pin order I got with my test. (Sorry about the messy image. I am too lazy to make it pretty...)There was no connection on pin 17 of mini HDMI connector. Not sure why though...However, I think the HDMI breakout board should work fine. So I am going to order the PCBs for that.

author: Songhua
author_rank: Contributor
timestamp: August 14, 2024, 08:59:05 pm
content: I'm very happy to see someone finally made an actual one.I read that you had problems with the pins.Did you fix it? Now. Please keep updating in this post. Appreciate your comments!

author: qmichl
author_rank: Newbie
timestamp: September 29, 2024, 08:32:46 am
content: I built also one with pod_sn65lvds low cost pods. And I found that the TLV74325PDBVR is a 2.5V LDO, while the SN65LVDS391PWR requires 3.0V-3.6V supply voltage. So that is the wrong voltage regulator. And R13 need to go to +3.3V instead of GND, otherwise half of the channels on the pod are disabled. The breakout_hdmi (not mini) seems to work so far, still testing.

author: qmichl
author_rank: Newbie
timestamp: October 04, 2024, 02:32:04 pm
content: The pod_sn65lvds pods do not have GND of the SN65LVDS391PWR connected, that need to be fixed by a small wire.The 100Ohm termination is not correct, that should be on the HDMI breakout instead on the pod_sn65lvds pod.

author: jsobell
author_rank: Contributor
timestamp: November 19, 2024, 12:14:34 am
content: Yes, I can see in the KiCAD schematic that the connectors pin numbers are incorrectI suspect @Oliv3r simply replaced the full size with a mini version without realising it had a different pinout.This is one of the main reasons I avoid KiCAD and use EASYEDA. At least with that product it uses the models directly from LCSC, so you're guaranteed to have the correct pinouts.Sorry, I don't see an easy workaround, other than either reordering using the standard HDMI breakout, or correct the mini HDMI breakout board replacing all HDMI_A with HDMI_C_1.3 components. It's the same schematic footprint, but with the pins corrected, but then you'll need to re-route the entire PCB to correct itHere are the two different connectors. Click the 'EasyEDA Model' link to see the pinouts.https://www.lcsc.com/product-detail/HDMI-Connectors_SHOU-HAN-HDMI-19PIN-043_C2858275.htmlhttps://www.lcsc.com/product-detail/HDMI%20Connectors_XKB-Connection-A71-05H4-111N1_C2682170.html

author: maxora
author_rank: Newbie
timestamp: February 05, 2025, 04:36:34 pm
content: Hi Guys,I'm back with a good news.As I mentioned in my previous reply, the Mini_HDMI_Breakout is not routed correctly.So I ordered PCBs for the HDMI_Breakout board andnow everything worksvery well.I'll attach some photos here.

author: Songhua
author_rank: Contributor
timestamp: March 15, 2025, 09:53:04 am
content: Great to know that you did it.Maybe some tests from different voltages can be appreciated.Could you share how you did it correctly from 0 to 1?

author: oliv3r
author_rank: Frequent Contributor
timestamp: March 24, 2025, 01:33:43 pm
content: Hey All, Sorry for missing all these posts! I checked a long time ago, but got nothing.It's great to see people took the plunge and tested that which I had not!!As for the mini-hdmi pinout; Unless I made a mistake in the schematic, then the connector pinout is incorrect, or rather, doesn't match 'the generic symbol'.So sorry for any trouble that may have causedAs for easyeda, this of course works great if you like their web-tool :p and don't want to store files in git, want to go to different suppliers etc. Also a lot of components from LCSC do not have symbols/footprints. And finally a big fault of mine is my OCD-ness I suppose. I prefer to use generic symbols and footprints as much as possible as those are far easier to 'read' and maintain (but some are sub-par for sure).The way I do work is using easyeda2kicad to pull in the parts directly from lcsc, so in _theory_ should yield the same results. However the mini-HDMI part has been a little bit ignored on my end, sorry. I just 'asssumed' that all HDMI pinouts where the same, but of course internally the connector can be quite different. I came up with the following pin-mapping, which matches the one found, where the 'missing one' should be GND (DDC/CEC-GND). Compared to the 'normal HDMI pinout': 2 1 3, 5 4 6, 8 7 9, 11 10 12, 14, 17, 15, 16, 13, 18, 19.I'll reroute the board to match.I have since do some small changes, was in contact with someone else interested and I made improvements on decoupling capacitors only really (which all already is in git).As I have to do another batch of pods, I'll look more closely at the mini-hdmi plugin to fix it. Thanks for the investigation!!Btw, the TLV743 I used is indeed the wrong one, the correct one C408972 (now updated) is what I should have put there. The datasheet wasn't very clear on the part (to me, I saw the absolute maxumum ratings for Vout and called it a day :p); and I overlooked it before. Thanks for pointing that out. Not found the missing ground connection though ...Curious though if the LED indicators work as expected thoughcan't see the bottoms or if they where soldered at all ...

author: @
author_rank: Contributor
timestamp: August 03, 2025, 11:02:53 am
content: Quote from: oliv3r on March 24, 2025, 01:33:43 pmHey @oliv3r, did you end up doing these fixes? The latest changes on Gitlab are from last autumn... Thanks for sharing your project!

author: oliv3r
author_rank: Frequent Contributor
timestamp: August 04, 2025, 12:55:56 pm
content: Quote from: @ on August 03, 2025, 11:02:53 amYes I did! May have not pushed it (or left on a branch). Did not test it though. Got my own boards, but haven't soldered those yetWill pick this up again soon-ish.

author: Songhua
author_rank: Contributor
timestamp: August 04, 2025, 11:36:20 pm
content: Good job 👍 . I'd like to see your demo.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 05, 2025, 03:41:50 pm
content: I have not read the whole thread, but have a Kingst LA2016 myself, and it uses a biasing network of resistors that is integrated with the input protection resistors t shift the logic thresholds a bit. I guess its a better solution then (attempting to) shift the GND level of the logic IC's.CH0comes directly from the input connector, andCH0Fgoes to some USBLC6-4SC6 clamping diodes, and then directly to the FPGA (EP4CE6F17C8N).

author: scopeman
author_rank: Frequent Contributor
timestamp: September 17, 2025, 03:27:46 am
content: Hello,Any progress on the mini HDMI fixes?Thanks!SamW3OHM