ESP32 Forum

Hey Everyone! I have a little weird situation with one of my recent projects. I've only worked with the ESP32-WROOM-32 module once before, but I've used the ESP32-S3 module multiple times. My recent design looks like this: IO0 reads as 3.3v and the boot button works just fine. IO2 is not soldered up so it is obviously not going to be a problem. Power and EN reads at 3.32v. My logic analyzer reports that EN has a 200us wait time from power-up. Meaning I don't see anything that could be wrong with it. I got the module from Digikey and kept it in its packing from the last moment. Since IO0 is pulled up in the first place the chips obviously not fake or dead. Yet I read absolutely no info from UART0. I tried putting it in download boot, and reset it, and there's absolutely no information out, and ESP-IDF reports no serial info when trying to upload to the chip. What am I doing wrong? I've soldered 3 different chips and desoldered 2 of them trying to see if it's a humidity or static problem.

Thanks for any help!
Let me know if you guys need more info!

TXD/RXD swapped in the connection of the serial adapter?
Disconnect the serial adapter and hook up the logic analyzer to TP2 to see if there's any data coming out of the ESP upon power up.

I wish that was the answer, but no I've tried both with a serial reader and no answer.
Here's the analyser with IO0 low, but no ESP-IDF: Here's the analyser with IO0 high: Here's the analyser with IO0 low, but with ESP-IDF trying to connect: Huh, I guess the RX and TX's got screwed up... Maybe I should try to have boot set, with ESP-IDF trying to flash and swap the rx and tx pins using an external converter? Doesn't seem likely since esp32s usually have some output on IO0 low, with no ESP-IDF interaction. Unless the esp32 is different.

Fwiw, on a 'stock' ESP32, I'd always expect some startup chatter on its TxD pin. If you don't see that at all, I'd suspect the basics: the connection to EN and the power supply.

GPIO5 must be in the log. 1 during boot
GPIO12 must be in the log. 0 during boot
GPIO15 must be in the log. 1 during boot

Hmm, interesting ideas. Well GPIO 12 reads 0v, and GPIO 15 reads 3.3v, yet GPIO5 reads 1.85v? Not sure what's going on there.
The power supply is A-ok, yet I'm not sure about the CHIP-PU input. As the schematic reads, I put down 10k ohms and 1uf, as the datasheet suggests, and my multimeter reads 10k for the resistor, but I don't know how to read the capacitor with a multimeter. I'm pretty sure I soldered a 1uf but I could just be insane. I may just remove the cap and replace it to be sure. What do you all think?

Thanks for all the suggestions so far!

Try to connect to the terminal, service messages should be visible when resetting, if configured correctly.