Help needed please - USB-C to micro-USB puzzles - Page 1
Forum section: electronics / general

author: Ultrapurple
author_rank: Super Contributor
timestamp: March 05, 2021, 03:06:27 pm
content: I have recently upgraded from a phone with micro-USB to one with USB-C. Both are (were) high-end devices from a highly reputable manufacturer and it is reasonable to assume the ports are implemented properly.Using the new phone with a Therm-App is provinginteresting. Only some cable and adapter combinations work - and I don't know why. I'm hopeful someone may be able to shed some light.I have been able to X-Ray the various connectors and present them here alongside photos of the cables.The first one is a curly micro-USB to micro-USB that worked fine on the older phone and now works fine with the new phone via a USB-C to micro-USB adapter widget (which I've also embiggened).The second is a rather chunky micro-USB to USB-C lead that I can't remember where I bought. It too works, although the connectors and cable are very clunky and not the sort of thing I'd want to use on a day-to-day basis.The third is very like the first, except that it's micro-USB to USB-C - and it doesn't work.Finally, we have a neat little right angle to right angle micro-USB to USB-C that would be perfect - if only it worked.I don't know enough about the connectors and protocols and so on for any informed insights on why the various ones work, or don't. Can anyone help?By the way I can't guarantee that the individual X-Rays of the connectors are the right way round: they could very well be mirror-image, for which I can only apologise. It is however safe to assume that if the connector looks like it's been soldered the wrong way round then it's my fault, not the manufacturers.Any help or comments will be most gratefully received.

author: Ultrapurple
author_rank: Super Contributor
timestamp: March 05, 2021, 03:10:43 pm
content: A closer close-up of the PCB in the white adapter.

author: Ultrapurple
author_rank: Super Contributor
timestamp: March 05, 2021, 03:16:41 pm
content: And a closer view of the PCB within the grey (working) USB-C plug.Bigger / better X-Ray images of any of these items can be made if required.

author: sleemanj
author_rank: Super Contributor
timestamp: March 05, 2021, 09:58:40 pm
content: \hard to be sure on the x-ray but looks like the non-working ones are missing the pulldown resistors in the type-c plug.

author: langwadt
author_rank: Super Contributor
timestamp: March 05, 2021, 10:15:17 pm
content: the connection of the ID pin? The end that has the ID pin grounded becomes the host with USB OTG

author: IwuzBornanerd
author_rank: Frequent Contributor
timestamp: March 05, 2021, 10:41:09 pm
content: It looks like @sleemanj is probably correct. The working ones (or at least one of them) have a pullup to V+ and another resistor to the OTG line so if the device is OTG that resistor will be grounded. See page 4 of the attached pdf.Edit: Looking at it some more after a nap, I see that none of the cables have the 5th wire & the cable that works with the adapter has the OTG pin connected to ground at both ends, so the adapter in the first case is seeing a ground there causing a pull-down on USB-C pin 5. If a device were connected that did not have the OTG pin grounded the phone would sense the difference, but the document I attached has me confused as to what that should indicate (seems backwards), but whether the resistors are present or not would present a different load to the phone.

author: Hydron
author_rank: Super Contributor
timestamp: March 06, 2021, 10:51:16 am
content: I can guarantee that it's a USB-OTG ID pin issue - have had this exact issue when getting a micro-usb-B FLIR dongle-camera working on a USB-C phone. I ended up modifying a micro-usb female to usb-c male adaptor (which are not wired for OTG use) to pull the appropriate USB-C pin to the correct voltage (I think it's to ground luckily) when plugged in. Was reasonably easy to do once I had cut the casing and potting compound off - connectors were joined via a tiny PCB with spaces for the resistors, and I could actually wire it up to switch depending on the micro-USB ID pin state. I suspect that if I'd had the white adapter in your first pic I would have had to do nothing.Looks like you actually want a male-male cable, like this:https://www.amazon.co.uk/gp/product/B01LONQ7R6/(I know this cable works for OTG with the micro-USB side as host, not sure about the USB-C end though which is what you need, and I don't have it here to test again unfortunately). Maybe worth a shot though, can probably return it if it doesn't work (Amazon has made enough money from the pandemic to deal with a few returns, especially given how little tax they pay in the UK at least).

author: Ultrapurple
author_rank: Super Contributor
timestamp: March 07, 2021, 02:10:07 pm
content: Thanks all.I have ordered a (further) handful of different USB C to Micro-B cables, from Amazon this time (all are Amazon Basics, and include the one Hydron mentioned) so we'll see what happens.It will be interesting to X-Ray the different cables to see what's inside them - particularly the one(s) that work.I've also ordered a half-dozen Micro B-C adapters that are hopefully like the ones I've already got that work. Most of my 'stuff' is based around Micro-B (for historical reasons) so they won't be wasted.Expect an update later this week.

author: Ultrapurple
author_rank: Super Contributor
timestamp: March 11, 2021, 03:48:51 pm
content: Thanks to Hydron for pointing me to the Amazon leads. I bought a selection and can confirm the following micro USB to USB-C cables work between a Samsung S20 5G and a Therm-App camera:Amazon Basics Double Braided Nylon USB Type-C to Micro-B 2.0 Male Cable | 3 m, Redhttps://www.amazon.co.uk/gp/product/B07CWGTKWJ/Amazon Basics Double Braided Nylon USB Type-C to Micro-B 2.0 Male Cable | 0.3 m, Redhttps://www.amazon.co.uk/gp/product/B07CWFNSSN/Amazon Basics Double Braided Nylon USB Type-C to Micro-B 2.0 Male Cable | 0.9 m, Dark Greyhttps://www.amazon.co.uk/gp/product/B07CWDYP18/And the one that Hydron suggested, Amazon Basics USB Type-C to Micro-B 2.0 Cable - 15.2 cm - Blackhttps://www.amazon.co.uk/gp/product/B01LONQ7R6/These cables were not cheap, at about GBP5 each, but they do work. I have spent a similar amount of money on cables that don't work.I will X-Ray these as soon as time permits and post the results here, though I note that the red and grey cables have aluminium shields over the connectors so my 35kV machine may have a little trouble penetrating that, depending on how thick it actually is.

author: firehopper
author_rank: Frequent Contributor
timestamp: March 11, 2021, 04:38:15 pm
content: I had to do the same sort of thing with a flir one gen 2 camera. its a micro usb, my newer phone is a usb c. found these on amazon and they work goodhttps://www.amazon.com/gp/product/B07D27SQT7/ref=ppx_yo_dt_b_asin_title_o08_s01?ie=UTF8&psc=1