Help needed to debug custom ESP32 Pico D4 PCB

[diyoio]

Hello,

I designed a board based on different circuits available online and I just received my assembled board but I'm not able to program the ESP Pico D4 module. The USB connection is successfully made with my computer but I get a timeout error when trying to flash the module with ESPIDF.

This is what I checked for now :

• All the connections seems to be OK, the only one I couldn't check is the ground connection below the module. I only did one small via to ground before I saw that ESP Pico Kit had several vias to connect the module to ground. Is it possible to check that module is connected to ground ?
• All pins requiring 3.3V are connected to 3.3V.
• IO0 and EN pins seems to be triggered correctly by the USB-UART module. (Quick check with an oscilloscope)

Am I suppose to see something on TX pin when I turn on power supply ? (I think i've read somewhere that the module sent messages at startup). This is my first real PCB project so any help would be greatly appreciated

You can find the schematics attached.

Thanks a lot !

[mikemoy]

Nothing jumped out at me besides the fact that you seriously need to put 0.1uf bypass caps on every power pin.
Maybe someone else catches something.

[diyoio]

Thanks a lot ! Can this lack of bypass caps cause the module not to boot up ? Also, is there any way to verify that my module is grounded or not ?

[mikemoy]

Can this lack of bypass caps cause the module not to boot up ?

Its hard to say every design and PCB is different.

Also, is there any way to verify that my module is grounded or not ?

I can't think of any with all the parts on the board. If the the ESP32 was the only part on the board you could use a multi meter in diode check mode across +3.3v and Gnd pin and you should see something other than a open circuit.

Did you poke the TX/RX pins with a scope to see if you see anything ?

[diyoio]

Did you poke the TX/RX pins with a scope to see if you see anything ?

Yep, 3.3V on both pins, nothing happens on TX but when I try to flash the module, I can see signal on RX pin...

Thanks for your help

[mspider65]

Exactly the same problem i have on my custom board.
viewtopic.php?f=12&t=14549

Did you also received the board recently from JLPCB?
Maybe is a faulty lot of ESP32 PICO D4.

[diyoio]

Exactly the same problem i have on my custom board.
viewtopic.php?f=12&t=14549

Did you also received the board recently from JLPCB?
Maybe is a faulty lot of ESP32 PICO D4.

Yes, my board has also been printed and assembled by JLCPCB... Did you try to contact them ? I'll send them a message now to check with them...