RGB Scope Probes ? - Page 1
Forum section: electronics / testgear

author: matthewpang
author_rank: Contributor
timestamp: December 04, 2017, 10:31:47 pm
content: Does anybody know if there are any vendors that offer RGB Scope Probes? An RGB led near the tip of the probe that would light up the same color as the scope trace would save me a huge amount of time every day. This should be a trivial function to offer on scopes with probe power/data interfaces.Extra props if the trace/probe color is user assignable . Super extra props if something like a math function could cause the probes of the relevant channels to change color to reflect the color of the math function trace.Admittedly less useful - (but I'd still be willing to pay a high price) if somebody can figure out a way to do the same with the logic analyzer on MSOs.This is lower value on 2 channel scopes but on anything 4 and up it gets really helpful. (Also very helpful if you happen to be using two or more scopes at the same time)

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: December 04, 2017, 10:52:01 pm
content: Well... isn’t that what the color coding slip-on rings are for? I have my probes color coded and these correlate with the channel color.What am I missing in your request?

author: tautech
author_rank: Super Contributor
timestamp: December 04, 2017, 11:25:02 pm
content: This has me wondering too.Hell, each probe is assigned AND compensated to a scope AND a particular channel where it should remain.Some coloured heatshrink indicating the channel and maybe coded to a particular scope too would be the cheapest/simplest fix. You could even go as far as using a fancy Dymo sleeve printer with channel colour match sleeving and add the scope it belongs to in print.If that's all too hard then coloured cable ties that indicate the channel and scope it belongs/is connected to.

author: nctnico
author_rank: Super Contributor
timestamp: December 04, 2017, 11:33:48 pm
content: Most (if not all) probes come with colored rings to help identify the channel they are connected to.

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: December 04, 2017, 11:36:14 pm
content: Besides: Active LED in the tip of my probes? I think I will gladly pass on such a feature: There is already to much noise to be picked up from anywhere else - no need to add to that intentionally :/

author: matthewpang
author_rank: Contributor
timestamp: December 05, 2017, 01:08:18 am
content: Quote from: frozenfrogz on December 04, 2017, 10:52:01 pm1) Because most of us are lazy and saving the few seconds every time we set up a measurement without needing to untangle the scope cables to match it to the right colored channel would be nice.2) I frequently swap the probes around between different instruments while not wanting to untangle the huge bunch of probe wires on/under/over/next to the D.U.T.3) I frequently encounter situations with things like multiple current probes. Since you need to cal these pretty before much every measurement - I'm not entirely fussed about pairing it to one channel. It would be really convenient to be able to stick it on whichever channel happens to be open and have the probe indicate the right color. This is especially true if the probe travels between different instruments.I know this is about savinga few secondsper operation - but it adds up dammit! I argue that this would genuinely make an improvement to the User Experience of a device.Most importantly -Because We Can.Because Whimsy. Because it wouldMake People Smile**Smile generated either from the awesome RGB party or from watching the video where Dave rants about it (or both).As a point of reference - IfMostmajorRAM manufacturerscan find a way to do RGB on DDR4 memory clocked at 3.6GHz for literally no practical purpose, I should damn well be able to buy RGB scope probes! Especially when there are valid reasons (other than it looks cool)QuoteI argue that for general stuff they're usually "close enough" without needing to do that.When the compensation is actually super critical for the measurement, I re-compensate the probe every time I hook it up just to bereally sure- don't you?Let's also be real here, all the major scope vendors have wasted way more R&D $$$ on way more expensive and far more useless features than this.Psssst: Danaher dudes, you know this isthe perfect$feature$ to $increase$ your $Average Selling Prices$People with pathetic non-RGB probes will suddenly feel just a little inadequate and start lusting for the upgradeYour probes will still be mostly compatible with other vendors products (so people on here won't bethatpissed off).This could be the little differentiator you're looking for in a sea of mostly feature comparable 3000 series scopes. Lets be honest - LOOK AT THE PRETTY LIGHTS , THINK ABOUT THE SEXY USER EXPERIENCE will workwaybetter than trying to endlessly complain about how some people operate on the screen memoryThink about all the cool marketing videos you could make ! Think about whose scope would look cooler in shootoutsThank about whose scopes would get attention at conferencesIn closing, Zo relaxen und watschender blinkenlichten!RGBRGBRGBRGBRGBRGBRGBRGBRGBRGBRGBRGBRGB!

author: TheSteve
author_rank: Unknown
timestamp: December 05, 2017, 01:28:15 am
content: I don't see anyone adding this feature. I will say though that Keysight has active probes with LED's for illumination so noise likely isn't an issue.

author: marshallh
author_rank: Unknown
timestamp: December 05, 2017, 02:14:02 am
content: I think the only issue would be with PWM on the leds to create more colors which would create switching noise. Obviously pure DC wouldn't have this issue, but at the expense of only having several color combos.Its a bit annoying to have probes mixed up but usually the plastic color rings sort it out anyway.

author: xrunner
author_rank: Super Contributor
timestamp: December 05, 2017, 02:24:00 am
content: But ... what four colors do you propose to use!I might buy into the idea if the four colors are very different - not like Rigol's choice 'cause two of the colors are TOO IDENTICAL!So what are your colors of choice?

author: matthewpang
author_rank: Contributor
timestamp: December 05, 2017, 02:39:03 am
content: Quote from: xrunner on December 05, 2017, 02:24:00 amOption 1 Here are the colors your could do without PWMRedYellow (Red +Green)GreenCyan (Green + Blue)BlueMagenta (Blue + Red)White (all)Red, Green, Blue and White/Yellow would seem to colors that you can drive without PWM that would be easily distinguishableOption 2 - Dim the LEDs without using PWM (e.g by simply varying the voltage)Option 3 - Sheathe the scope cable out of a fiber optic material and have the source further away. This could happen either in the scope or in your probe connector (since it has to have the special connector for probe power and data anyway) This could be virtually noise free if you were careful about where you put the noisy PWM stuff and if necessary you could use light pipes). The benefit of this is that the whole cable would light up - and as we know - the more RGB the better

author: nctnico
author_rank: Super Contributor
timestamp: December 05, 2017, 11:15:18 am
content: Quote from: marshallh on December 05, 2017, 02:14:02 amAny reasonable opamp can drive a LED as a current source and the dissipation is minimal. A switching PSU for driving one LED is probably consuming more energy by itself than the LED and a series resistor.

author: coppice
author_rank: Super Contributor
timestamp: December 05, 2017, 11:52:22 am
content: Quote from: nctnico on December 05, 2017, 11:15:18 amI agree. The mention of RGB has people reacting like the probe should illuminate the room with high efficiency.When did you last see any LED indicator use PWM, unless a spare PWM output from an MCU was the cheapest way to drive that LED. Lots of indicators have modulated brightness, and its usually done is a simple continuous time manner.

author: Gyro
author_rank: Super Contributor
timestamp: December 05, 2017, 12:13:45 pm
content: Surely your main problem isn't with the LED, it's persuading all of the scope manufacturers to support them.If you don't have some common interface on the scope to drive the colour, then what's left, a selector switch and a battery? At that point you are far better with the coloured sleeves on the probes.

author: coppice
author_rank: Super Contributor
timestamp: December 05, 2017, 12:37:07 pm
content: Quote from: Gyro on December 05, 2017, 12:13:45 pmThat has always been a problem with adding features to probes. Automatic x1/x10 switching has been around since the 70s, yet there is still no standard for it, so it only works when the scope and the probes match.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 05, 2017, 01:12:36 pm
content: LeCroy offered this with some of their probes. Personally for the 10X, I just use the plastic rings to keep track of where they go.

author: tablatronix
author_rank: Regular Contributor
timestamp: December 05, 2017, 01:23:13 pm
content: Could always use fiber optics in the cable to avoid noise.

author: xrunner
author_rank: Super Contributor
timestamp: December 05, 2017, 01:59:24 pm
content: Quote from: matthewpang on December 05, 2017, 02:39:03 amMy personal favs (undesirables striked out)RedYellow (Red +Green)GreenCyan (Green + Blue)BlueMagenta (Blue + Red)White (all)Also how about a white LED at the end somewhere like a flashlight, to light up the circuit board in dark places?

author: Gyro
author_rank: Super Contributor
timestamp: December 05, 2017, 02:08:50 pm
content: Quote from: tablatronix on December 05, 2017, 01:23:13 pmOf course, if you run the fibres up to the channel markers on the screen and stick them there you'll be able to get an exact, manufacturer independent, colour match.

author: Pinkus
author_rank: Frequent Contributor
timestamp: December 05, 2017, 02:09:24 pm
content: So if you think there is a need/market for this: do a kickstarter. I would suggest a retrofit add-on to existing probes. This makes you rich - and don't forget to patent your idea.... well it might be too late now ....

author: matthewpang
author_rank: Contributor
timestamp: December 05, 2017, 10:55:31 pm
content: Disclaimer : This started as a joke that occurred to me while working on a project for a client where we need an automated test setup to be able to query the scope over I2CIn the cruel light of day - this is probably funny and stupid enough to warrant a proof of concept at least. Here are some ideas that would enable retrofitting existing standard probes.Hardware Design:An "RGB adapter" sits between your scope and probe. It has a thru for the BNC connection. It is physically compatible with common smart/active probe interfaces. The adapter also connects to a (replaceable?)glowing fiber optic cable sleevethat wraps around your probe cable and top of your probe (you have the option to cut it down to length). The BNC thru and the RGB driver are aggressively shielded from each other as much as possible. We use the quietest possible LED drive scheme.Software:A MCU in the RGB adapter talks to the the scope via the serial probe interface (a generic software library supports as many major scope vendors as possible) and drives the RGB. Here are some possible features:We light the sleeve/probe up according to the channel colorIf we are doing a Math Operation - we change the color of the relevant probes accordinglyWhen probing a serial bus (e.g SPI) - we blink the corresponding probe as we assign the different pinsWhen setting up the trigger - Blink/Highlight the probe that is being used as the trigger source.If we are changingsettings specific to a channel- we blink/highlight the corresponding probeIf the scope needs to alert you to a problem on a channel (e.g measurement out of range) we change the color/blink the appropriate probeDifferent user selectableRGB effectsfor funThe adapter is open source and user programmable (Arduino compatible?) over USB so users can add their own functionalityAny other ideas?

author: IDEngineer
author_rank: Super Contributor
timestamp: December 05, 2017, 11:31:29 pm
content: Quote from: xrunner on December 05, 2017, 02:24:00 amAnd Rigol's dark blue is TOO DARK. It's a full color display, a whole spectrum of color options, why not pick four colors that are NOT perceived as "dark" to human eyes?I wonder if any T&M equipment maker has made their channel colors customizable by the user. Again, it's a full color display. Precisely zero technical reason this can't be done. It's one more byte of data per channel (yielding 256 colors). Yeah, there's the whole probe tip color ring coordination thingie, but if that's a big deal for you, stick with the default colors. Me, I'd be happy with four rings labeled 1, 2, 3, and 4 and the ability to set my own screen colors. It would make screenshots SO much easier to work with, etc.I'd seriously consider replacing pieces of equipment just for this option. When you stare at these screens for hours every day, little things like legibility matter a LOT.

author: james_s
author_rank: Super Contributor
timestamp: December 06, 2017, 12:50:04 am
content: I think there is very little market for such gimmicky features in professional equipment. I certainly wouldn't bother with it, the little colored rings work just fine and I almost always plug my probes into the same channel because the compensation is perfectly adjusted to that channel. The last thing we need is another proprietary scope probe feature, the Tek probe coding is enough hassle already.RGB LEDs have already plagued computer hardware for a while now, we don't need the fad to spread. I have to go out of my way these days to find CPU coolers and fans and such that aren't covered in dorky LED bling.My TDS784C has customizable trace colors, I think there are 8 options, maybe 16, I don't recall but it's a ~25 year old instrument. I use one of the stock configurations which has nice contrasting and easily visible colors, red, green, yellow and blue.

author: matthewpang
author_rank: Contributor
timestamp: December 06, 2017, 03:03:58 am
content: You say gimmicky I say : makes my life easier.Another example : I probe a lot of serial busses many times a day. If I'm probing an SPI interface - as i'm selecting MOSI/MISO/SCK/CS ports, the corresponding RGBLED on the probe would blink to tell me which was which.Could I spend the extra minute looking carefully - sure I could. But why shouldn't I want life to be easier?

author: james_s
author_rank: Super Contributor
timestamp: December 06, 2017, 06:50:28 am
content: You make it easier in one way, and harder in others. Adding the RGB LEDs means more hardware, more programming, more testing, more places for bugs to creep in, more potential connections to fail, proprietary probe interfaces, extra cost, etc. You're welcome to try, but I wouldn't bet on selling enough to break even. It's a solution looking for a problem, which few others seem to have.

author: Keysight DanielBogdanoff
author_rank: Unknown
timestamp: December 06, 2017, 08:13:36 am
content: I think it's a cool idea! It almost certainly won't be a thing for the "lower end" passive probes, but the higher end stuff already communicates with the scope on some level so it's in the realm of possibility in the long run.

author: tablatronix
author_rank: Regular Contributor
timestamp: December 09, 2017, 03:00:05 pm
content: Your gonna need fairly large fiber, and a lot of light.I would prototype this using off the shelf toslink cables, preferable with the standard 1/8" phono optical jacks (or the adapters) on them instead of toslink, it would be easy to make the light distribution box for these to plug into.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 09, 2017, 04:33:02 pm
content: There should also be RGB on the scope itself, and a sensor on the probes. So when you get confused from all the probes, you just pick up a probe and the scope it's connected to can start flashing, either in soothing lava-lamp colors, or harsh 1990's industrial music club strobing.

author: JohnPen
author_rank: Regular Contributor
timestamp: December 10, 2017, 09:06:35 am
content: Perhaps all new designs should include different wavelength LEDs for each test point! Then use a wide band optical detector, using a suitable lens above the PCB, followed by selectable narrow band frequency resolution to enable the 'scope' to display each test point signal in the appropriate colour. A simple colour selector switch on the 'scope' or s/w to automate the process for diagnostics to display the relevant signals.

author: tooki
author_rank: Super Contributor
timestamp: December 18, 2017, 01:26:31 am
content: I thought the primary point of the color rings on scope probes is that a particular probe has to be compensatedfor a particular input, and that if you use a probe on a different channel of the same scope (never mind on a different scope) you are supposed to compensate it again. So the rings ensure that you always use the same probe on the same channel input. So unless you’re gonna also include software-controlled probe compensation, and include an EEPROM so that the probe saves its calibration constants for every input it’s used on, this whole exercise is for naught.