ESP32 Forum

Hello all. I have developed a custom board based on esp32s2-wroom device. I have tested it with alot of code (UART, Timmers, GPIO, Interrupts...) and everything works great. BUT:

When i try to upload a wifi code (even the simpliest scan code) it allways says this:

I (479) wifi:wifi driver task: 3ffd891c, prio:23, stack:6656, core=0
I (479) system_api: Base MAC address is not set
I (479) system_api: read default base MAC address from EFUSE
I (489) wifi:wifi firmware version: c44a5e7
I (489) wifi:wifi certification version: v7.0
I (489) wifi:config NVS flash: enabled
I (499) wifi:config nano formating: disabled
I (499) wifi:Init data frame dynamic rx buffer num: 32
I (509) wifi:Init management frame dynamic rx buffer num: 32
I (509) wifi:Init management short buffer num: 32
I (519) wifi:Init dynamic tx buffer num: 32
I (519) wifi:Init static rx buffer size: 1600
I (519) wifi:Init static rx buffer num: 10
I (529) wifi:Init dynamic rx buffer num: 32
I (529) wifi_init: rx ba win: 6
I (539) wifi_init: tcpip mbox: 32
I (539) wifi_init: udp mbox: 6
I (539) wifi_init: tcp mbox: 6
I (549) wifi_init: tcp tx win: 5744
I (549) wifi_init: tcp rx win: 5744
I (559) wifi_init: tcp mss: 1440
Exception in thread Thread-2:
Traceback (most recent call last):
File "threading.py", line 932, in _bootstrap_inner
File "threading.py", line 870, in run
File "C:/Users/Nasib/Desktop/esp-idf/tools/idf_monitor.py", line 166, in _run_
outer
self.run()
File "C:/Users/Nasib/Desktop/esp-idf/tools/idf_monitor.py", line 378, in run
data = self.serial.read(self.serial.in_waiting or 1)
File "C:\Users\Nasib\.espressif\python_env\idf4.2_py3.8_env\lib\site-packages\
serial\serialwin32.py", line 259, in in_waiting
raise SerialException("ClearCommError failed ({!r})".format(ctypes.WinError(
)))
serial.serialutil.SerialException: ClearCommError failed (PermissionError(13, 'A
cceso denegado.', None, 5))




Is like the device doesnt want to enable the wifi.... what do you think that could be happenning??

I am super lost now...

Thank you so much in advance for your help

Best regards...

Sounds like you have a brownout and your USB-serial bridge chip (or the ESP32S2 itself, if you're using internal USB) is falling off the USB bus. Make sure your power supply can deliver >=500mA on the 3.3V rails, and that the supply lines are sufficiently decoupled. If you have pics or schematics of your hardware, we can take a look at it.

We make custom boards as well, for mass production. I fully agree on ESP_Sprite's contribution above to be the most likely cause. In addition, make sure you have a proper reset cycle at the beginning. We once had spurious side effects, similar to what you describe, when we did not do a proper reset. The board seemed to have booted fine, but crashed (much) later.

Thanks all..

What I don't understand is that any other code is perfectly working in my custom board but the WiFi... If other codes are charged correctly I suppose that it is not a hardware problem right? .. not decoupling nor even reset or insufficient current from the usb right ?

The WiFi subsystem is very spikey in its power requirements; when enabled it can require high currents for a short while. It can overload a power supply that is otherwise perfectly capable of running the rest of the SoC.

See here is our schematic, based on voltage regulator LM3691 and two selector diodes, to choose between USB power or Lithium-Polymer battery. This works fine. If you want, post your schematic for a look and comment.