ESP32 Forum

Hello everyone.

I’m working on a project were the ESP32 is the brains, I would like to program automatically using the CH340E USB to serial adapter.

I followed the guide over at GitHub (https://github.com/espressif/esptool/wi ... -Selection) but it releases its magic smoke every time I plug the USB into it.

I’m not sure if it’s this that is causing the problem but I’ve tried only populating the PCB with the ESP32 and the components for the USB to serial and I still get the same problem.

I’ve attached a schematic of the programming part, could anybody give some feedback on it?

Thanks in advanced

What, exactly, releases the magic smoke? The CH340 or the ESP32? If it's the ESP32, we'd also like a schematic from that bit. Furthermore, have you tried measuring using a multimeter to see if e.g. your USB plug pinout isn't wrong or you accidentally have a short feeding 5V into the ESP32 instead of 3.3V?

Having a look at the schematic here: https://github.com/rocketscream/CH340E- ... 40E-MB.pdf, your smoke is probably coming out because you have V3 (3.3V) connected to VCC (which should be 5V). That will be sending 5V to the ESP32, where it only wants 3.3V.
This does seem to be a difficult chip to get a decent datasheet in English for though. This one https://www.mpja.com/download/35227cpdata.pdf appears to be largely right, but V3 shows as NONE instead of pin 10 in the MSOP10 package.
Edit: removed comment about DTR/RTS

Your schematic portion shows a short between V3 and the 5V rail, which will be sending 5V to the ESP32.
Also, Your net label for VCC is "3.3V/5.?", which seems like it's trying to be both 3.3 and 5. They need to be separate.

Hello,

i´m wondering how this should work. CTS is an input to ch340E. You need DTR for flashing. DTR don´t exist on CH340E.
Thanks