Can't upload when oled featherwing attached Moderators: adafruit_support_bill, adafruit

[jonmon6691]

Hi there! I'm having trouble uploading a sketch to my Huzzah32, but only while the 128x64 OLED Featherwing is attached. Error pasted below. I tried all the possible upload speeds but they all result in the same error too. I've only soldered the pins the pins that the oled wing actually needs, and also the corner pins to keep it stable while plugged into the header sockets. See the pins circled in red below.

Pins connected to Huzzah32:

Screen Shot 2022-05-20 at 6.19.19 PM.png (193.96 KiB) Viewed 61 times

Error message:

Code: Select all | TOGGLE FULL SIZE

esptool.py v3.3
Serial port /dev/cu.SLAB_USBtoUART
Connecting.....................................An error occurred while uploading the sketch
.

A fatal error occurred: Failed to connect to ESP32: Wrong boot mode detected (0x13)! The chip needs to be in download mode.
For troubleshooting steps visit: https://docs.espressif.com/projects/esptool/en/latest/troubleshooting.html


Has anyone had this problem before? Its a big pain to disconnect the screen every time I upload!

[jonmon6691]

Solved it! In case it helps someone down the road; I took a look through the troubleshooting guide linked in the error message (go figure) and after some digging it looks like the stability of the flashing process is dependent on the capacitance between the reset pin and ground, specified to be somewhere between 1-10uF. The Huzzah32 board has this capacitor but it's 1uF, the minimum recommended. Somehow attaching the featherwing pushed things over the edge and it wasn't enough.

To fix it I soldered a 10uF capacitor between the reset pin and ground, it now uploads reliably with the OLED featherwing attached!

[Franklin97355]

Thanks for posting your solution.