Ah, it doesn't say GPIO12, but rather MTDI under the strapping pins section, so I didn't get it before. So, in my next revision of my board it should avoid using these pins then; - GPIO0, GPIO2, GPIO5, GPIO12 and GPIO15 (because they are strapping pins) - GPIO6, GPIO7, GPIO8, GPIO9, GPIO10 and GPIO1...

Strapping pins? Do you mean soldering bridges? Or something else?

I'm using GPIO_12 as the SCL for my I2C on the other board. It is pulled high by the I2C pullup resistors. Is GPIO_12 (physical pin 14) not usable?

Hi guys, this might be a hopeless question to answer, but maybe someone has a bright idea. I've made a custom PCB with a ESP-WROOM-32 on it. Then I've made another PCB (with all my sensors), and connect those two board together using a 60-pin connector. If I start up my ESP-board when the other PCB ...

Correct, I only did 'make app-flash' out of habbit, since that's what I normally do on the Sparkfun Thing.
I did a 'make flash' now, and it works even when I turn the Bluetooth back off again

For some reason it works when I enable Bluetooth, as Rudi describes here.

Hi, first a disclaimer - my problem might be related to my own poorly designed PCB, but I'm not sure so I'll ask. I've made a custom PCB for an ESP-WROOM-32. I've gotten two testprograms, that both work on my Sparkfun Thing, to work. One is a Blinky app, and the other has an interrupt that reacts wh...

Aha, very nicely troubleshooted.

I did infact copy this folder based from a previous project. The template I'm working out from is about 25 days old, did the default value get changed more recently than that?

Hi, looking at the traces from the logic analyzer I see that the one I did on the Teensy show a very stable 100KHz clock signal. On the trace I did on the ESP32 the clock signal is more like 98-99kHz, and does have some weird ticks, like for instance the 65kHz tick in the screenshot below. http://st...

This book is a fantastic resource for ESP32!

Thanks, so 263 = 0x107 = ESP_ERR_TIMEOUT.