hybridfree/eevblog-posts huggingface dataset:
Usb C power supply - Page 1
Forum section: electronics / beginners

author: sintax69
author_rank: Unknown
timestamp: July 29, 2018, 01:19:52 am
content: Does any one have information on how USB C works.I see it supplys 5v 12v 20v and I just wanted to know how this is all doneIs it possible to us usb c to supply my ts100 iron using a adaptor cable and also supply a DP30V5A power supply. Just tryinbg to reduce the amount of power bricks under the desk

author: JS
author_rank: Frequent Contributor
timestamp: July 29, 2018, 04:22:41 am
content: Belive TS100 uab is data only, but you could feed any DC between the required ranges to the DC jack.TS80 is the newer (?) which power via a USB C port but most USB supplies are quite wimpy for soldering, compared to the 24V 4A used in many cases... The extra power really helps while soldering big planes so be aware.JS

author: sintax69
author_rank: Unknown
timestamp: July 31, 2018, 06:17:45 am
content: What I was thinking was to cut a usb c able and use a 5.5mm DC jack into the back of the ts100 then that going to usb c plug which then plugs into a usb power supply

author: tarker
author_rank: Newbie
timestamp: October 07, 2018, 12:22:08 pm
content: HiThe voltage selection of USB PD (Power Delivery) used with the Type-C connectors works based on a rather complicated data protocol.USB PD PSUs only supply the default 5V until the "consumer" device negotiates a transition to a different mode with a higher voltage.If You have a suitable USB PD power supply and You want to power your TS100 from it using for example the 20V mode, then You will need a module with a USB PD controller which will do the "consumer" side negotiations to get the supply to the 20V mode.In fact, the MCU used in the TS100 is capable of providing a USB PD interface and acting as the controller, but obviously the TS100 does not have the required connections and connectors for that.It would be interesting to see if anyone can hack the TS100, add a Type-C socket and run it on the USB PD 20V mode...The TS80 does that by itself, and requests the 9V mode from the PSU.Erik
USB C to USB C connector? - Page 1
Forum section: electronics / beginners

author: cart
author_rank: Contributor
timestamp: December 06, 2021, 12:45:34 pm
content: Hi everyoneI just want to confirm somethingSo a USB C to USB C cable is not just two plugs and a couple of wires wired 1 to 1? Is there really a IC inside the connector? Does that mean if you put a signal on the one side it will in all likely hood not reflect on the other side?Lets say I build a little system that uses Female USB C breakout boards. I just want a simple HIGH on the one end to reflect on the other end so I can run it into an MCU. However if there is an IC inside the USB C Plug thenmy simple signal has a high chance on never reaching the other side right?ThanksCart

author: sleemanj
author_rank: Super Contributor
timestamp: December 06, 2021, 01:07:50 pm
content: Mostly it is just a wire, E-marked cables include a chip which will communicate on the cc pins (and draw power from vconn - gnd).

author: Terry Bites
author_rank: Super Contributor
timestamp: December 06, 2021, 04:39:06 pm
content: seehttps://en.wikipedia.org/wiki/USB-C

author: ejeffrey
author_rank: Super Contributor
timestamp: December 06, 2021, 11:21:22 pm
content: Also keep in mind only some of the wires are there.A standard USB type C socket has two sets of USB 2.0 data pins but only one pair is actually present. You are meant to connect them in parallel to support reversible cables.The superspeed pairs are optional and any given cable might have 0, 2, or 4 pairs present. You don't connect them in parallel, if you only want to use 2 you need a switch that selects the right pairs based on cable orientation.CC pins are used for detection and can have an etag chip connected.
USB cable power testing - Page 1
Forum section: electronics / beginners

author: thefamilyman
author_rank: Regular Contributor
timestamp: July 02, 2015, 07:41:31 am
content: Good evening ladies and gentlemen.This is my first post after many years watching Dave on YouTube.Please be nice to meI don't know how many of you get annoyed at shitty micro USB cables that don't allow your device to charge at high amperage because of their voltage drop, but it annoys me.With inspiration from mjlorton, I've decided to start testing the voltage drop from many cables; brand name factory cables, popular expensive ones and inexpensive ones, to really see how they perform under load.Over the next month or so (dependent on shipping times) i will be purchasing as many nice looking and spec'd cables i can find and run them past my crude but kinda effective testing setup.My setup will consist of the following:YZXstudio USB power monitor with voltage sense tap-offA DC electronic loadPower supply with voltage sense to allow accurate 5V input with minimal lossMultimeter to measure the voltage at the micro USB end.I'll be measuring Voltage input from the calibrated ZXYstudio power monitor and the voltage output with my multimeter.With these simple measurements along with several different current loads i can calculate the voltage drop and power loss along the cable itself with minimal and controlled external factors.with these calculations i then can devise a standardised performance rating, something like power loss per metre as all cables would end up being varying lengths and a price/performance index.included are some photos from my rather crude test setup that i used to test consistency. As you can see the micro USB socket at the end needs to be implemented in a better way, any suggestions?I'm open to all suggestions, constructive criticism and ideas, also please let me know some cables you would like me to test too.Patrick

author: jaromir
author_rank: Unknown
timestamp: July 02, 2015, 08:29:30 am
content: You can short out the device end of cable, set power supply to 1A CC mode and read out the voltage from the supply itself, if is accurate enough (or use DMM). The voltage in Volts will be equal to resistance in Ohms, for both conductors in series.It has downside - it will be much simpler and easier, the setup will not looks as appealing, as the amount of needed laboratory equipment will decrease, not sure if it will not be a problem.

author: Balaur
author_rank: Unknown
timestamp: July 03, 2015, 10:25:42 am
content: My take on this
USB cable shield no continuity is OK? - Page 1
Forum section: electronics / beginners

author: smile
author_rank: Regular Contributor
timestamp: March 03, 2018, 04:31:12 pm
content: Hello, I recently got few USB 2.0 cables with gold plated ends etc.They do not have continuity on the shield, as the cable ends do not have continuity. Are they out of spec?What's the point in gold plating if it's not connectedThanks.

author: amyk
author_rank: Super Contributor
timestamp: March 03, 2018, 05:12:19 pm
content: According to USB spec, the shield should be grounded at the host end only.More information here:http://www.microchip.com/forums/m267325.aspx

author: Gyro
author_rank: Super Contributor
timestamp: March 03, 2018, 05:38:49 pm
content: That's within the 'slave' device though, not the cable connectors.The cable should have shield continuity from one end to the other. I suspect your nice gold plated cables don't have an sort of shield, probably just 4 cores.

author: smile
author_rank: Regular Contributor
timestamp: March 03, 2018, 06:46:24 pm
content: Quote from: Gyro on March 03, 2018, 05:38:49 pmThat could be the case, as these were from china, as everything these days.The resistance is between 4 wires is OK.I had some wires that shield was connected but the resistance was crazy, the resistance for data pins was high also. Probably fake cable steel instead of copper, the strange thing the cable worked OK for programming arduino

author: Gyro
author_rank: Super Contributor
timestamp: March 03, 2018, 07:01:07 pm
content: QuoteI was holding back on suggesting that possibility! Scanning around ebay, it looks as if most Arduino clones connect the Shield to PCB ground so the extra ground path probably helped you out in that case. Funny how things work out!

author: beenosam
author_rank: Regular Contributor
timestamp: March 03, 2018, 07:25:44 pm
content: Quote from: smile on March 03, 2018, 04:31:12 pmGold plating makes people think the cable is better and it adds class/style

author: smile
author_rank: Regular Contributor
timestamp: March 03, 2018, 07:46:04 pm
content: Gold plating really makes cables or any connectors better, but only if they are made properly in the first place.Furthermore it seems as china gold plating is simply titanium plating, because it looks the same and is cheaper then gold plating. Anybody thinks the same?Regarding the cable, I will get my money back, but I should not use it because of potential data loss etc?
USB cable tester - a thing I wish I had years ago - Page 1
Forum section: electronics / beginners

author: cfmsoft
author_rank: Newbie
timestamp: March 01, 2025, 11:12:54 pm
content: Hello all.I recently found on aliexpress a very simple USB tester to test all my camera and iPhone data cables and I really wish I had found this tester years ago. It would have saved me several headaches.The tester is a very simple board, with on the top side one connector for power, two power side connectors for USB-A and USB-C cables and on the bottom side 3 device side connectors for micro-USB, USB-C and Apple lightning cables.With it I found immediately which cables are for charging only (do not have data lines) and which cables are broken and ready for the garbage bin.Example of a good iPhone cable. power and data lines light up, only CC remains dark because only USB-C cables may have that extra connection.This is an example of a good USB-C cable with all 5 leds on.Another example of a good USB-C cable that lacks the CC connection, may be good for some devices but not for others.I found that this cable is for charging only. Has no data lines whatsoever and that's the reason that when I tried to connect my camera to the computer it said there was no device connected...Last example is a broken cable. Only tho lines are actually connected, the ground and one of the data. Directly to the trash...

author: Simmed
author_rank: Frequent Contributor
timestamp: March 01, 2025, 11:23:53 pm
content: not my work, but

author: cfmsoft
author_rank: Newbie
timestamp: March 01, 2025, 11:44:48 pm
content: Thank you for your reply.I Have ordered that one yesterday, but for the last half a year the DT3 has done a very good job for 2.5€ and I think it is easier for other people who do not understand electronics.
USB cam not detected!  - Page 1
Forum section: electronics / beginners

author: u666sa
author_rank: Frequent Contributor
timestamp: December 05, 2023, 05:23:35 pm
content: I have this usb cam connected to linux notebook for video recording. It was working fine, but then.... Camera is not detected.. Okey. I a USB thumb drive into USB port, it is detected, port is fine.. Camera is bad? I plug camera into different notebook and camera works fine. What could it be?

author: magic
author_rank: Super Contributor
timestamp: December 05, 2023, 05:25:30 pm
content: Quote from: u666sa on December 05, 2023, 05:23:35 pmdmesg has answers to all your questions

author: u666sa
author_rank: Frequent Contributor
timestamp: December 05, 2023, 06:06:11 pm
content: Quote from: magic on December 05, 2023, 05:25:30 pmIt does not! Inserting device does nothing. No messages. Nothing. Nada.Same device inserted into different notebook and it works just fine!

author: magic
author_rank: Super Contributor
timestamp: December 05, 2023, 08:59:45 pm
content: Simply connecting a 10kΩ resistor between D+ or D- and 5V should result in "new USB device" messages. (Data lines are pulled down by the port and a device announces its presence by pulling up one of them).You could tryCode:watch -n 1 'cat /proc/interrupts |grep hci'to monitor interrupts from the various USB controllers (OHCI/UHCI/EHCI/XHCI). Interrupt count should increase when anything happens on the corresponding bus, including connection of a new device (and countless other things, like moving a USB mouse).If the count increases but there are no messages, perhaps it's software. If it doesn't, it's probably hardware, because I don't think there is any way software could program the port to selectively ignore one particular device. BTW, be sure to test other device of the same speed (cameras can be full, high or super speed) to confirm that the port really works correctly.

author: liaifat85
author_rank: Regular Contributor
timestamp: December 08, 2023, 11:58:54 am
content: Run the lsusb command to see if the camera appears in the list of connected USB devices. Look for the camera's details to confirm if it's detected by the system at the USB level.

author: magic
author_rank: Super Contributor
timestamp: December 08, 2023, 12:32:14 pm
content: Of course it doesn't.
USB chargeable Li-ion AA battery quality? - Page 1
Forum section: electronics / beginners

author: GregDunn
author_rank: Frequent Contributor
timestamp: May 10, 2019, 04:20:42 am
content: I have a number of devices which use standard 1.5V AA batteries, but I'm quite nervous about using alkaline cells in them because of their known tendency to leak and ruin equipment. I've seen these USB-chargeable 1.5V Li-ion AA batteries for sale but I can't find much in the literature about their quality and reliability.Are these a good choice for devices like multimeters or non-critical remote controls? Sometimes mine sit for weeks or maybe months at a time before I haul them out for use, and I'm willing to trade the necessity of recharging them periodically for the safety of not having them leak in a neglected device. I like the fact that they deliver ~1.5VDC, and they won't be used for heavy current draw so the smaller capacity is not an issue.

author: plurn
author_rank: Regular Contributor
timestamp: May 10, 2019, 04:52:45 am
content: Good question. I would like to know too.I have been using low self discharge NiMH batteries (eg Eneloop and others) in place of AA and AAA to protect my equipment from battery leaks as NiMH batteries do not leak electrolyte. I have had them in things like tv remote controls for years without needing to charge them.There may be some devices where 1.5V per cell is important and 1.2V per cell (NiMH) won't work. I expect if that is the case it would be pretty rare? Maybe a problem in devices that use lots of batteries as the difference adds up? 6 x 1.5V = 9V. 6 x 1.2 = 7.2VFrom what I have read, Alkaline batteries work from 1.6V down to about 1V. They somewhat linearly drop from 1.6V down to 1V as they are used so they don't spend much time at 1.5V. So most gear would probably take that into account and will work at all those voltages including below 1.5V.NiMH batteries work from about 1.4V down to about 1V and spend most of their time at 1.2V (fairly quickly drop to 1.2V as they are used, then level out, then when most of their capacity is used they drop quickly to 1V) so most of their time is within the operating range of an Alkaline cell.Anyway still curious about USB-chargeable 1.5V Li-ion AA batteries, so hope someone can respond about that.

author: GregDunn
author_rank: Frequent Contributor
timestamp: May 10, 2019, 05:01:54 am
content: I'm pretty sure the 1.2V will work in a lot of devices, but one particular use is a strobe trigger for my photo system, and the 2 AA batteries in it die pretty regularly because of how far the alkaline cells drop during use - when they get down to the 1.1-1.3 range they're goners. Bad design, maybe, but it really needs the 1.5V. I haven't tested NiMH in my current batch of portable meters.

author: viperidae
author_rank: Frequent Contributor
timestamp: May 10, 2019, 06:48:47 am
content: You'll find that NiMH cells have lower internal resistance than alkaline, so they will perform better in high current devices despite the lower open circuit terminal voltage.
USB Charger - is it really Vin: DC6-35V - Page 1
Forum section: electronics / beginners

author: ...kuba...
author_rank: Newbie
timestamp: May 19, 2025, 03:59:10 pm
content: Hello,I bought a USB charger based on the SW3518 IC. I wanted to power it with DC32V but after connecting it starts to heat up terribly, mainly one of the AON7534 MOSFETs. Is it really for power supply up to 35V? in the auction description it was up to 32V... looking at the board I see that one MOSFET at the GND input is as if to limit the supply voltage, but it is not it that heats up. In addition, from the data sheet of AON7534 i see that V_DS has 30V but I do not know if it matters.Should this charger work on Vin 32V without overheating?

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: May 29, 2025, 10:49:23 am
content: According to the datasheet, SW3518 can allow 6~40V.https://make.net.za/wp-content/datasheets/SW3518%20Translated.pdf?srsltid=AfmBOoqbZOG5_GOw0WLVIBvXYnnfZCedtTmJ-qZtoc0EiuRoP-V2HHAHHowever, I was going through the description of the SW3518 modulehttps://www.aliexpress.com/i/1005005787027117.html#nav-specificationIt says Input Voltage Range: 3.3-21vCheck the specs of the particular module that you are using. The module has many more components. It's possible that those components cannot withstand up to 40V.

author: radiolistener
author_rank: Super Contributor
timestamp: May 29, 2025, 11:28:01 am
content: check capacitors voltage rating, if its 20V, then 35-40V can damage it

author: MLXXXp
author_rank: Frequent Contributor
timestamp: May 29, 2025, 09:30:16 pm
content: Quote from: ahsrabrifat on May 29, 2025, 10:49:23 amThe silkscreen printed on the module in the posted photo says:VIN:DC6-35V

author: Zero999
author_rank: Super Contributor
timestamp: May 30, 2025, 12:51:58 pm
content: I found a translated data sheet for the IC here:https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://make.net.za/wp-content/datasheets/SW3518%2520Translated.pdf%3Fsrsltid%3DAfmBOor0jjWbPGxFC0PpP5skbV83o-jZ7vxfX3YvTcjTC6Na0QmqTd1q&ved=2ahUKEwjY68DSnMuNAxXBZ0EAHU9mDV0QFnoECBYQAQ&usg=AOvVaw3vmbeVOxoOulJEDsUD4_EoIt says input voltage range 6V to 40V, but in your case the MOSFETs used are only rated to 30V, so you shouldn't exceed that.I doubt it will maintain 5V out, with 6V in, especially at low voltages.Running at the upper end of the voltage specification, with the output set to 5V, will introduce additional losses, especially at higher currents.
USB charger pcb - Page 1
Forum section: electronics / beginners

author: ResR
author_rank: Regular Contributor
timestamp: March 19, 2013, 04:08:16 pm
content: I think I messed up something, it's a 4 port usb charger. The USB sockets has wrong size, when I find any to measure I update it to better.http://sphotos-h.ak.fbcdn.net/hphotos-ak-prn1/74399_448557395223706_1970050788_n.jpgSo any suggestions would be nice._
USB Charger Recommedation? Magnetic? - Page 1
Forum section: electronics / beginners

author: Magnetic Wizard
author_rank: Newbie
timestamp: March 06, 2018, 01:03:24 am
content: Not sure where to post this but I am currently looking for USB charger recommendations.I found this one which I like:https://www.target.com/p/quirky-octo-charge/-/A-52304809Also found here:https://shop.quirky.com/products/magnechargehttps://www.amazon.com/dp/B074ZQSVD7This USB charger appears to have a built-in magnet for attaching to most surfaces. For example it says it can be attached under desktops and tables to help keep cable clutter to a minimum. The built in magnet would probably make this an excellent garage tool/charger as well.Just shopping around and looking for a quality product. Any suggestions? Has anyone tried the magnetic USB charger?Thanks

author: Jwillis
author_rank: Super Contributor
timestamp: March 06, 2018, 01:20:28 am
content: Those arn't chargers but just 5 volt supply via usb .The charger for phones, ipods is on board and only requires a exterior 5V supply.So if thats what you need to charge a phone or mp3 player then any 5v usb supply will work.

author: Magnetic Wizard
author_rank: Newbie
timestamp: March 06, 2018, 01:24:49 am
content: Yes I'm looking for something different and the built-in magnet on this one seems useful. Thanks for clarifying...
USB Charging Voltage/Current - Page 1
Forum section: electronics / beginners

author: olsenn
author_rank: Frequent Contributor
timestamp: September 16, 2013, 01:17:55 pm
content: I have a device that outputs 5.2 volts under no load; however, drops down to 3 volts (or lower) by the time an amp or so of current is being drawn. My question is, for USB charging devices, how do they determine how much current to use?Will my phone for, instance, use as much current as it can without bringing the charger voltage below 5 volts, or do these devices drain a fixed amount of current and expect the charger to be able to maintain 5 volts at that current?
USB Data Sockets - Mini vs Micro vs Standard how electrically compatible r they? - Page 1
Forum section: electronics / beginners

author: jakeisprobably
author_rank: Regular Contributor
timestamp: July 15, 2016, 08:51:14 pm
content: I have a small early 90's Sharp PDA keyboard, and I've already rigged up it's matrix with the PCB of a current USB 2.0 keyboard. I took the time to desolder all of the old undocumented chips and made enough clearance for the USB keyboard PCB to fit inside the PDA's case. My last step is to attach and wire up a USB port. The PDA had a small proprietary side computer port that is just large enough I could fit a mini or micro USB socket inside it and make the design look factory. The USB keyboard PCB used a standard 4 wire USB connection. I've tried to read into the details about different connections and USB terminals but it has been really difficult for me to find a straight, practical answer.Can I connect my 4 terminals from a USB 2.0 HID keyboard directly to the pins of a USB mini or micro socket AND connect that socket to a computer's usb port using a standard USB to Micro (or Mini) connector cable?Obviously I could make my own cable, but I have a lot of the Standard to mini/micro cables around and I do not want to have to keep up with a custom one.

author: sleemanj
author_rank: Super Contributor
timestamp: July 15, 2016, 11:51:24 pm
content: It is just a connector. Mini/Micro have an extra pin for device id, leave it unconnected.
USB device needs a lot of additional current to turn on, possible problems? - Page 1
Forum section: electronics / beginners

author: Mp3
author_rank: Frequent Contributor
timestamp: March 14, 2018, 08:55:12 am
content: Hi everyone,i have a USB piano type keyboard i can't turn on.It is supposed to be powered by usb or dc power. Sometimes i could get it to turn on by using a 2.5a 5v power supply even though it only needs a 600ma! sometimes it will not turn on at all.I did not find any out of range values checking the capacitors with an esr meter,What can i check?

author: Psi
author_rank: Super Contributor
timestamp: March 14, 2018, 08:59:37 am
content: Did you measure it drawing additional current with a meter?or are you just saying that because it seemed to work with a 2.5A power pack and would not work with it's normal lower current pack?

author: Mp3
author_rank: Frequent Contributor
timestamp: March 14, 2018, 09:01:32 am
content: Quote from: Psi on March 14, 2018, 08:59:37 amThe latter, but for what it's worth, i couldn't get it to power on with a different 600ma psu, and even a 1a power supply, only the 2.5a would do it! (yes polarity correct on all), i assume some component must be drawing a crazy amount of current. Do i need to use a scope or can i do this with a dmm?

author: Psi
author_rank: Super Contributor
timestamp: March 14, 2018, 09:07:55 am
content: If you're getting an additional 5V 1A draw then something will be getting very hot.First thing i would look for is another internal switch-mode converter. Maybe generating 3.3V, and confirm the output is good.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 14, 2018, 10:07:39 am
content: Are you using a cheap dodgy USB cable ? Many cables are well below spec for conductor size.

author: kjr18
author_rank: Regular Contributor
timestamp: March 14, 2018, 10:16:20 am
content: Quote from: Mp3 on March 14, 2018, 09:01:32 amI had similar problem with a xbox one controller, on stand-by it was drawing like 20 times more. One switch mode converter was getting hot, but what failed was one mlc cap near next power supply ic. I think that something like that might be an issue. Check outputs for shorts.

author: Mp3
author_rank: Frequent Contributor
timestamp: March 14, 2018, 10:42:00 am
content: Quote from: mikeselectricstuff on March 14, 2018, 10:07:39 amTried many usb cables of different qualities; i will be checking cap again, i am brand new to esr meters so the chance i missed something is high.
USB device not working with extension cable - Page 1
Forum section: electronics / beginners

author: dog80
author_rank: Regular Contributor
timestamp: October 16, 2013, 12:50:45 pm
content: I have a cheap set of USB powered speakers and I wanted to integrate a USB sound card into the speakers so they can work with just the USB cable plugged in (no MIC IN cable).Problem is that the sound card (it is this one:http://img.ebw.gr/9001/usb-sound-card.jpg) doesn't seem to work with an extension cable attached. Even the LED won't turn on.The voltage drop across the USB extension cable is insignificant, however I replaced it with a short piece of Cat5e cable (much thicker wires) soldered directly on the board.Still no luck. Sometimes windows will pop a message that the device is not recognised. I tried the rear USB ports too and still nothing.Any ideas?

author: dog80
author_rank: Regular Contributor
timestamp: October 16, 2013, 12:53:17 pm
content: Here's the wiring:

author: amyk
author_rank: Super Contributor
timestamp: October 16, 2013, 12:55:42 pm
content: USB has acable length limit.3m for low speed, 5m for full and high speed.

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: October 16, 2013, 12:59:10 pm
content: The red/black cable doesn`t look like its connected to anything ? .

author: dog80
author_rank: Regular Contributor
timestamp: October 16, 2013, 01:01:33 pm
content: Quote from: amyk on October 16, 2013, 12:55:42 pmThe length of USB cable I used was about 1 meter. The cat5 cable even less.

author: Short Circuit
author_rank: Frequent Contributor
timestamp: October 16, 2013, 02:01:16 pm
content: - USB cable pair needs to be twisted up to the connection point.- It seems you are powering the speakers from the USB also; probably too much (inrush) current

author: dog80
author_rank: Regular Contributor
timestamp: October 16, 2013, 02:08:47 pm
content: I redid the solder joints and it seems to work for now....

author: amyk
author_rank: Super Contributor
timestamp: October 16, 2013, 08:59:20 pm
content: Quote from: Short Circuit on October 16, 2013, 02:01:16 pmVery critical for high-speed, not so much for full and low.

author: Monkeh
author_rank: Super Contributor
timestamp: October 16, 2013, 10:33:18 pm
content: Quote from: amyk on October 16, 2013, 08:59:20 pmStill no excuse for not even trying to keep wires twisted up to termination.

author: Kryoclasm
author_rank: Regular Contributor
timestamp: October 16, 2013, 11:45:27 pm
content: You might want to add an external regulated 5v source to power the speakers and just use the data lines of the usb. That way you will have plenty of power available.

author: peter.mitchell
author_rank: Super Contributor
timestamp: October 17, 2013, 04:46:00 am
content: Quote from: Kryoclasm on October 16, 2013, 11:45:27 pmEither that or whack in a buttload of capacitance. The speakers probably want a reasonably low impedance power supply.

author: wraper
author_rank: Unknown
timestamp: October 17, 2013, 06:49:01 am
content: Try to connect shield of the cable to the audio card where connector body was soldered.
USB DPDT Switch Question - Page 1
Forum section: electronics / beginners

author: bhj99
author_rank: Contributor
timestamp: May 05, 2023, 02:31:50 pm
content: Hi all, I am am looking at a reference design involving a USB 2.0 DPDT switch NLAS7222A and was curious on the choice of resistor values R54 and R55 for the select input S on pin 10. The USB_EXT_VBUS would be 5V nominal. So, the voltage at pin 10 would be 5*(1/1.75) = 2.86V. From my understanding, wouldn't any V_IH of > 1.3V make the select input go high and just choose the resistors for the divider to meet that requirement? Or is there something in particular that I'm missing.

author: jwet
author_rank: Frequent Contributor
timestamp: May 05, 2023, 03:40:55 pm
content: The part isn't 5v tolerant on logic inputs so they are making a voltage that is comfortably under 3.3v even at worst case USB voltage high. I think they're just trying to make this clear.
usb extender  - Page 1
Forum section: electronics / beginners

author: abdullahseba
author_rank: Frequent Contributor
timestamp: April 10, 2014, 08:50:59 am
content: if i plug my vga or usb to RJ45 extender in a router will it be on the network

author: GeoffS
author_rank: Unknown
timestamp: April 10, 2014, 08:56:18 am
content: Extenders are point to point, they don't change the signal to be network routable.

author: tszaboo
author_rank: Super Contributor
timestamp: April 10, 2014, 08:56:32 am
content: no.

author: Shock
author_rank: Super Contributor
timestamp: April 10, 2014, 10:46:20 am
content: If you still value your router working, don't plug anything aside from network cables connected to proper network ports into your router.You can get USB and VGA over Ethernet type interfaces to properly convert the signals.By themselves USB cables are good up to several meters (~5m) depending on the cable quality and the source device.You can then stick a power hub on the end of that and extend them further.VGA is no good after a few meters but with HDMI cables you can easily get 10 meters or so with a decently made $10 cable.
USB galvanic isolation - Page 1
Forum section: electronics / beginners

author: lhc
author_rank: Contributor
timestamp: July 12, 2010, 08:00:47 pm
content: I'm currently looking for some kind of USB galvanic isolation to protect my computer from too high voltages connected to USB ports. It has to be quick and support USB 2.0 at full speed (optocouplers are too slow for this, they only work good for RS-232 speed)I have a ISP programmer with optoisolation but there are other devices that would need that kind of protection (i will be buying logic state analyser in the future and some other USB stuff).There are few expensive isolators, maybe somebody has some nice schematics or links to some inexpensive devices?

author: Zero999
author_rank: Super Contributor
timestamp: July 12, 2010, 08:51:19 pm
content: How about pulse isolation transformers?

author: Unknown
author_rank: Unknown
timestamp: July 12, 2010, 10:23:02 pm
content: USB isolators are going to be expensive because of the high frequencies involved, it would probably require and USB transceiver on both sides of the transformer. If the USB is converted to something like UART or SPI inside the device, it's much easier to isolate that. I like the RF isolation devices like the AD iCoupler and similar devices from Silabs. There is a USB device in that line, but it's expensive and only does USB 2.0 full speed (which ironically is not at full speed).

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 13, 2010, 01:51:30 am
content: If you wait for a deal, you can get a wireless USB hub kit for about $20.

author: StephenOng
author_rank: Newbie
timestamp: July 13, 2010, 02:05:05 am
content: You can have a look athttp://www.circuitsathome.com/products-page/usb-interfaces. They sell a kit based on ADuM4160. The chip supports USB 2.0 full speed, not high speed.

author: chiaTu
author_rank: Newbie
timestamp: July 13, 2010, 02:18:35 am
content: Try Silicon Lab's Si8410/20/21Supports speed up to 150Mbps. Easy to use. The only trade of is that you need to provide power to it from each side.
USB Ground referencing - Page 1
Forum section: electronics / beginners

author: codycode
author_rank: Newbie
timestamp: April 17, 2016, 06:09:03 pm
content: So I decided that I wanted to make a powered USB cable.The layout goes something like this; Wallwart USB charger -> VCC, GND -> Female USB <- D+,D-,GND <- LaptopSo my laptop's ground will be referenced to the charger's ground, or in other words I'm referencing the grounds of 2 USB busses together.I just wanted to make sure that this would not cause some sort of ground loop, or power contention. So does this should potentially harmful, or should this work just fine?

author: stmdude
author_rank: Frequent Contributor
timestamp: April 17, 2016, 06:40:48 pm
content: I can't figure out how you want to wire this thing up. Maybe a picture would help us understand?If it helps, the "ground" on USB Wall chargers is floating, so it'll adapt to whatever ground-potential your laptop has.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 17, 2016, 09:49:18 pm
content: This is one reason why PSUs have isolated outputs.If your USB charger does not have isolation... send it backTim

author: Michaelbradford
author_rank: Contributor
timestamp: April 18, 2016, 12:18:42 am
content: Check out bigclive.com on you tube he does a lot of USB stuff msg him he quite good
USB ground shared between ports? - Page 1
Forum section: electronics / beginners

author: Molenaar
author_rank: Regular Contributor
timestamp: January 24, 2016, 11:27:50 am
content: I want to connect two USB dev boards (on the same PC) to each other. Do I need to connect ground seperately or would ground already be shared through the USB ports?Thanks!

author: tooki
author_rank: Super Contributor
timestamp: January 24, 2016, 11:53:32 am
content: They're shared, and in most cases it's actually connected through to mains earth. I think that theoretically, connecting the grounds more closely (between the development boards) can reduce noise, though.

author: Molenaar
author_rank: Regular Contributor
timestamp: January 24, 2016, 12:31:10 pm
content: Thanks!

author: bcbeck96
author_rank: Newbie
timestamp: January 25, 2016, 04:46:20 pm
content: yeah, defiantly if you can provide a low impedance ground between the two boards, it is connected through usb but always best to connect them
USB Host Shield Error - Page 1
Forum section: electronics / beginners

author: MasterSnipes
author_rank: Newbie
timestamp: March 11, 2015, 12:57:54 am
content: Hey there! I recently got a USB Host Shield from Circuits@Home and I ran the test program and here are the results I got:Circuits At Home 2011USB Host Shield Quality Control RoutineReading REVISION register... Die revision invalid. Value returned: 00Unrecoverable error - test halted!!0x55 pattern is transmitted via SPIPress RESET to restart testI also ran the PS3BT sketch in an attempt to connect a PS3 controller to the Arduino via bluetooth but I got "OSC did not start" multiple times after once when I got "PS3 Bluetooth library" which made me all likeand I was filled with joy but that quickly faded as I got "OSC did not start" very soon after that.I feel likeSomebodyPleaseHELP!

author: mazurov
author_rank: Frequent Contributor
timestamp: March 11, 2015, 01:02:09 am
content: Have you soldered 2x3 header?

author: MasterSnipes
author_rank: Newbie
timestamp: March 11, 2015, 01:59:18 am
content: Yes, I have but what would a good connection look like?

author: mazurov
author_rank: Frequent Contributor
timestamp: March 11, 2015, 02:12:14 am
content: A good picture of a soder job would be helpful. Also, try running Arduino from external power source.

author: MasterSnipes
author_rank: Newbie
timestamp: March 11, 2015, 11:25:42 pm
content: How would I know if the USB Host Shield worked or not? If I am running from an external power source.Quote from: mazurov on March 11, 2015, 02:12:14 am

author: mazurov
author_rank: Frequent Contributor
timestamp: March 12, 2015, 12:05:16 am
content: Take a picture of your solder job and post it here.
Usb hub and their crystal - Page 1
Forum section: electronics / beginners

author: Raj
author_rank: Frequent Contributor
timestamp: March 19, 2020, 06:13:40 pm
content: I was looking at fe1.1s hub chip datasheet. It uses 12mhz crystal. (Unrelated, but so does most Arduino projects that run on vUSB liabrary.)What I was wondering, how can a hub chip that runs on 12 mhz, allow for transfer speeds of upto 40mbps? Some kind of frequency multiplication is happening I guess?Also, please suggest a simpler usb 2.0 alternative usb hub ic from a good chip brand (for reliability)

author: dferyance
author_rank: Regular Contributor
timestamp: March 19, 2020, 07:01:47 pm
content: Likely a phase locked loop where an oscillator is synced to the crystal via a feedback circuit. So yeah, in a sense frequency multiplication.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: March 26, 2020, 01:30:53 pm
content: I've never seen a hub with a 12mhz crystal. I seriously doubt they even exist.I've seen plenty with a 12MHz crystal though. It's just a difference of a factor of 1000000000

author: Raj
author_rank: Frequent Contributor
timestamp: March 26, 2020, 03:12:49 pm
content: LOLI'll refuse to edit it just to keep your comment relavent.
USB Hub IC - Will this work? - Page 1
Forum section: electronics / beginners

author: mastermaker7000
author_rank: Newbie
timestamp: July 05, 2025, 03:06:41 am
content: I am using this USB2514B IC to access two USB devices (Cypress FX2 and FT2232) on my PCB with just one USB C port. I followed the datasheet the best I could but am not confident this will work on the first try.For example, I need USB high speed, but for the pin strapping configuration, I must pull the CFG_SEl1 / HS_IND pin low according to the datasheet. Would this not disable high speed since I am pulling HS low?The non_rem and cfg pins are confusing me and I need help to make sure I understand them correctly.Here is the datasheet:https://ww1.microchip.com/downloads/en/DeviceDoc/00001692C.pdfI have attached a picture of my schematic below.Also this is my first forum post, so I am sorry if I did anything wrong!
USB hub power adapter exploded cuz of too much power consumption - Page 1
Forum section: electronics / beginners

author: koko0
author_rank: Newbie
timestamp: September 24, 2016, 08:47:57 pm
content: small intro -Hi!1. new here, but very not new in the eevblog video series. i'm addicted to it.2. English is not my main language, feel free to correct me so i can learn more than just electronics.- end of introI've built a usb fan to absorb fumes when im soldering.i didn't put any resistor there, cuz i thought nothing too bad should happen (small motor of a dead quadcopter). i've connected it to a USB hub outside of my compter so i couldn't damage it.well, the fan started to slow down after a few seconds so i've turned it off. then the power adapter (that thing that is connected to the wall) flashed few times and powered down my home.my questions are -shouldn't it be protected from happening? it's just cuz it's a cheap adapter?why would it explode after i turned it off?some post-magic-smoke pictures added for your pleasure.

author: elgonzo
author_rank: Unknown
timestamp: September 24, 2016, 10:12:31 pm
content: That wall wart is as cheap as it can get. Zero protection whatsoever.I guess the same is true for the USB hub itself. Did you purchase it from ebay or one of the Chinese online shops like Alibaba?What was the power or current rating for this wall wart, and what is the current rating of the fan/motor?From the pictures it's hard to tell what went up in smoke. There is no visible damage to the components, and the charring is on the bottom side of the PCB. Thus, my guess is that the fan drew more current than the traces on the PCB of the wall wart could handle, causing one or more of the PCB traces to heat up until charring occurred. The charring (perhaps mixed with some displaced copper from molten traces) established an electrically conductive path with sufficiently low resistance between the two mains terminals which eventually tripped the mains fuse...

author: Brumby
author_rank: Unknown
timestamp: September 24, 2016, 11:15:41 pm
content: Quote from: koko0 on September 24, 2016, 08:47:57 pmThat was not the best move, IMO. Those motors are designed to deliver POWER - enough to lift themselves, an airframe, battery and electronics. You just needed to move air.The overload was inevitable and, obviously, severe. It is not inconceivable that once there was damage in the wall-wart, it entered upon its own destructive path.

author: IanB
author_rank: Super Contributor
timestamp: September 25, 2016, 12:41:14 am
content: The best kind of fan to use would be a small case fan from a PC. Although designed for 12 V these will usually run quite happily on 5 V.

author: koko0
author_rank: Newbie
timestamp: September 26, 2016, 09:39:28 am
content: Yeah that was a very cheap one from ebay.Nothing was written on it as far as i remember.I bought some 5v fans from ebay to try to build another one.Funny thing - the seller offered me a new one... Not sure if i want it.Thanks!
USB isolation problem? - Page 1
Forum section: electronics / beginners

author: MapleLeaf
author_rank: Contributor
timestamp: November 01, 2015, 12:21:45 am
content: Just got some smoke out of a ST Discovery board! It was hooked up to my PC via USB and my Rigol ds2017 scope. With the O-scope and board not hooked up, I measured the USB ground and O-scope ground and got 68 mV. The Discovery board still works but a diode by the USB port is a little burnt. For some reason my PC ground is different from the rest of my bench. Both are on the same circuit coming into the house. Ground loops? Cheap PC power supply for USB?So i need a USB port isolator before i burn up something really important.It needs to be self powered. I think USB 1.x is good enough for the stuff i play with.Any suggestions on what is good or bad for USB isolators?Anybody else have this problem?

author: Andy Watson
author_rank: Super Contributor
timestamp: November 01, 2015, 12:28:43 am
content: In this situation that you have described, 68mV should not cause any smoke! Are you sure that you didn't short out the +USB voltage?

author: MapleLeaf
author_rank: Contributor
timestamp: November 01, 2015, 02:10:11 am
content: Nope. The ST discover board was being powered by the PC's USB port. No open USB cables. Only the scope was hooked up when the USB cable was plugged in and the smoke came out.

author: mij59
author_rank: Frequent Contributor
timestamp: November 01, 2015, 08:12:58 am
content: Ground loops are unlikely, you could check by connecting an ampmeter between the grounds.Looks to me you connected the ground lead of the scope to the positive terminal of theusbST Discovery supply.A while ago I bought a usb isolator based on the ADUM4160 on eBay,http://www.ebay.nl/itm/USB-protection-ADUM4160-Evaluation-Board-USB-Isolator-/161078762151?hash=item25810adaa7:g:OtkAAMXQ4uJR-5Wj]http://www.ebay.nl/itm/USB-protection-ADUM4160-Evaluation-Board-USB-Isolator-/161078762151?hash=item25810adaa7:g:OtkAAMXQ4uJR-5Wj] http://www.ebay.nl/itm/USB-protection-ADUM4160-Evaluation-Board-USB-Isolator-/161078762151?hash=item25810adaa7:g:OtkAAMXQ4uJR-5Wj

author: Gyro
author_rank: Super Contributor
timestamp: November 01, 2015, 09:49:09 am
content: Are you measuring that 68mV on the DC or AC range? If on DC then it might (just possibly) be an artifact of a more significant AC voltage - worth a quick check.USB 1.1 isolators are getting relatively cheap now, I had to make my own when I needed one. You need to check is that they can output enough power, a lot are limited to 1W (200mA), assuming the ST Discovery board doesn't have a mains adapter.

author: Jeroen3
author_rank: Super Contributor
timestamp: November 01, 2015, 01:28:34 pm
content: Pulling the maximum of 2ma leakage of a laptop supply through one of the data pins as 0.5*mains is enough to kill your USB port.

author: mikerj
author_rank: Super Contributor
timestamp: November 02, 2015, 07:06:55 am
content: Quote from: Jeroen3 on November 01, 2015, 01:28:34 pm2mA is unlikely to smoke a typical diode though.
USB LCD display? - Page 1
Forum section: electronics / beginners

author: bifferos
author_rank: Regular Contributor
timestamp: January 02, 2023, 11:29:04 pm
content: Some years back I purchased a USB controlled 4-line HD44780 display from Sure electronics. I figured it'd be easy to buy something similar today. Unfortunately my searches proved fruitless, either for this device itself or anything like it. It's basically a mini-B connector, with a CP2102 and some kind of micro-controller controlling the display, but the key thing is this is all in one package. I didn't need an Arduino, or the i2c-> HD44780 backpacks (which still need USB->i2c) just a serial device you send chars to in a self-contained package.Is there some equivalent to the above available now? Thanks!

author: Salome2
author_rank: Regular Contributor
timestamp: January 03, 2023, 03:26:48 am
content: https://www.aliexpress.com/store/900905/pages/custom-1569986212776.html

author: ledtester
author_rank: Super Contributor
timestamp: January 04, 2023, 08:27:21 pm
content: Like this?https://www.adafruit.com/product/784Also check out the Matrix Orbital site:https://www.matrixorbital.com/communication-protocol/usb

author: coromonadalix
author_rank: Super Contributor
timestamp: January 05, 2023, 06:39:46 am
content: Bring back souvenirsLcdSmartie was a good software for some models EDIT: Still alive it seemsSome of them use AIDA with pluggins to display some infos ....

author: bifferos
author_rank: Regular Contributor
timestamp: January 06, 2023, 02:01:35 am
content: Quote from: ledtester on January 04, 2023, 08:27:21 pmThat's exactly what I wanted, thanks!NB: I also found the same backpack on its own:https://shop.pimoroni.com/products/adafruit-usb-serial-lcd-backpack-add-on-with-cableWhich would allow me to have a 4-line display.

author: kjr18
author_rank: Regular Contributor
timestamp: January 07, 2023, 08:35:41 am
content: Nah, LCDSmartie is pretty much dead at this time. While software works and site is online, there was no update since forever.As for usb lcd, it depends how you want to control it, be it Matrix orbital protocol or lcd2usb driver, you can even use arduino to do it for you, just write what you want to display to serial port, and forward it to display. I used one for some time with matrixorbital sketch and used lcdsmartie to show various data like cpu usage, cpu temp etc.Edit: Just found that someone has updated lcdsmartie here:link to github page

author: bidrohini
author_rank: Regular Contributor
timestamp: January 08, 2023, 01:06:21 pm
content: Quote from: bifferos on January 06, 2023, 02:01:35 amYeah. I think Adafruit USB + Serial Backpack Kit with 16x2 RGB backlight negative LCD will be a good product. Text color and background color, both can be changed.