Search found 45 matches

by dave111
Wed Apr 04, 2018 10:41 am
Forum: General Discussion
Topic: Issue with 1 out of 10 touch buttons
Replies: 25
Views: 27698

Re: Issue with 1 out of 10 touch buttons

Interesting. Thank you. Let me see, if I can make this work. Or maybe I just try to live with 9 touch buttons. Regarding the Android specific issue I mentioned above: I now consider this to be a shortcoming in the user level USB serial library I am using. It's not really a big issue, once you get us...
by dave111
Tue Apr 03, 2018 8:46 am
Forum: General Discussion
Topic: Issue with 1 out of 10 touch buttons
Replies: 25
Views: 27698

Re: Issue with 1 out of 10 touch buttons

Things are starting to make sense! Thank you both vm for your replies. I am still wondering... - Why can't Android devices (as host) achieve gpio0 bypass/passthrough? My Android terminal app does not raise dtr or rts (just like minicom on Ubuntu also does not). If I raise rts on Android for test pur...
by dave111
Tue Apr 03, 2018 2:18 am
Forum: General Discussion
Topic: Issue with 1 out of 10 touch buttons
Replies: 25
Views: 27698

Re: Issue with 1 out of 10 touch buttons

I quickly summarize: As long as the Lolin32 lite is connected to my PC, all 10 touch signals (T0-T9) work just fine. When I disconnect it from my PC and run it from battery or via wall charger, one of the touch signals (T1, which is attached to gpio-0) stops working. I assume the UMH3N is blocking t...
by dave111
Mon Apr 02, 2018 9:23 pm
Forum: General Discussion
Topic: Issue with 1 out of 10 touch buttons
Replies: 25
Views: 27698

Re: Issue with 1 out of 10 touch buttons

Archibald wrote: You may be able to gain some insight into what is going on with your Lolin32 Lite board by measuring the RTS and DTR voltages on the UMH3N dual transistor. Incidentally, the circuit diagram of the board does not show the 4.7KΩ base resistors within the UMH3N. On the Lolin32-Lite, t...
by dave111
Mon Apr 02, 2018 6:06 pm
Forum: General Discussion
Topic: Issue with 1 out of 10 touch buttons
Replies: 25
Views: 27698

Re: Issue with 1 out of 10 touch buttons

Right. The other two boards come with a cp210x uart, but the Lolin32-lite comes with a ch341 uart. Also fact: The Android devices I own do not come with ch341 driver. I overlooked this so far, because I was always able to receive the logs from all three devices. Not sure how this is possible. Maybe ...
by dave111
Mon Apr 02, 2018 3:22 am
Forum: General Discussion
Topic: Issue with 1 out of 10 touch buttons
Replies: 25
Views: 27698

Re: Issue with 1 out of 10 touch buttons

Interesting. And good to know I'm not the only one who has run into this. I won't be able to use the MPR121 for this, but that should be OK. Because lolin32-lite is able to provide 10 working touch sensors. You can see them all lined up here, including T1: https://i.imgur.com/tsi2iSj.png This was ca...
by dave111
Sun Apr 01, 2018 10:07 pm
Forum: General Discussion
Topic: Issue with 1 out of 10 touch buttons
Replies: 25
Views: 27698

Re: Issue with 1 out of 10 touch buttons

Hmmm. Is there some shared understanding among board vendors that no sane person will want to ever use all 10 touch sensors and therefor T1 or T2 or both can be sacrificed for other purposes? I created a 2-wire USB cable (no data wires, 5V only) to test with my lolin32-lite boards. T1 still fails wh...
by dave111
Sun Apr 01, 2018 12:51 pm
Forum: General Discussion
Topic: Issue with 1 out of 10 touch buttons
Replies: 25
Views: 27698

Re: Issue with 1 out of 10 touch buttons

I have new data. I was able to test with two ESP32 boards from other vendors. It does not look like rts/dtr handling is having anything to do with the issue: ESP32 board connected-> PC Ubuntu 16.4 Nexus 9 7.1 plain USB power / no data --------------------- -------------- ----------- ----------------...
by dave111
Sat Mar 31, 2018 12:52 pm
Forum: General Discussion
Topic: Issue with 1 out of 10 touch buttons
Replies: 25
Views: 27698

Re: Issue with 1 out of 10 touch buttons

This theory cannot be right, because some of the configurations, in which the issue also occurs, are when the board is connected to some USB host - just not my main PC. A) T1 fails if board is connected to an Android tablet (being USB host) and it is being powered by the tablets battery. B) T1 fails...
by dave111
Sat Mar 31, 2018 8:22 am
Forum: General Discussion
Topic: Issue with 1 out of 10 touch buttons
Replies: 25
Views: 27698

Re: Issue with 1 out of 10 touch buttons

Don't understand, sry. How does battery power differ from grid based power when both are connected via USB?

Aside from that, the same issue occurs also with several grid based power supplies.

Most importantly: can you come up with an idea on how to tackle this issue?