ESP32 Forum

Hello

I am using two ESP32C3 and both only run the programm when I connect them to my PC. When I use the 3,3V Input via a normal power supply the program does not start.
And when I’ve disconnected the board for a long time it is not enough to only connect it again. I have to upload the same code again to make it run. Both boards show this behavior. Any advice?

Does it work when you press the RST button after you apply power?

Hi, I could fix this issue. I was using 3,3V from a laboratory power supply, but becase the power loss was so huge I had to use 3,5V to make it run.
However...by now I have discovered a way bigger problem: When I upload my code the programm starts running and everything works fine. But when I cut off power for a short moment and put it on again(externally or PC), the code does not get executed anymore. I have to plug power off and on again many times to make it work. Pressing Restart does not change anything. Unconnecting the USB-C, pressing Boot, reconnecting the USB and letting the Boot button go afterwards does help, but there must be a way to fix this problem. It would be extremly unreliable if you have to restart the board like this every time afer power got cut off. (also it has nothing to do with the code, the same behavior showed while making a LED blink)
Maybe I have to put a capacitor somewere? Has anyone had this problem as well? I did not find much about it on the internet.

That is an odd issue; pressing RESET ought to clear all issues. There's nothing else connected to the board I assume?

You can also port your question to the seedstudio forum: https://forum.seeedstudio.com/

Could it be related to the LDO or other power management circuitry hasn't output discharge feature? Just trying to guess.

Franco wrote: ↑

Tue Jul 18, 2023 10:16 am

Could it be related to the LDO or other power management circuitry hasn't output discharge feature? Just trying to guess.

Was thinking about the same. I can't find any documentation saying that the XIAO can be powered via its 3v3 pin at all...
LDOs can behave weirdly when fed voltage from their output side w/o input voltage.

I'm having nearly the same issue. My program only runs when connected to my macbook via USB-C. If I connect it to an external USB-C power supply, it doesn't work. I just received 3 from AliExpress a few days ago and haven't tried powering via pins yet.

Did you also by chance order from AliExpress? I'm wondering if maybe they're counterfeit.

Do you do the following after Serial.begin() ?:

while (!Serial);

Remove it.

^^ That saved me! Thank you!