ESP32 Pico D4 Custom PCB not working

dan_jim_23
Posts: 6
Joined: Fri Mar 06, 2020 1:18 pm

ESP32 Pico D4 Custom PCB not working

Postby dan_jim_23 » Fri Mar 06, 2020 1:36 pm

Hello,

I have realized a custom PCB design for the ESP32 Pico D4 and I’m not able to program it.
To reduce the components needed I use a separated USB-FTDI adapter to program the SIP.
I tried to reproduce the schematic of a similar board that successfully use the USB-FTDI adapter.
Because I don't need the Wifi part I didn't connected anything on the antenna input.
Debugging with the scope on the USB-FTDI lines I cannot see a “TX” signals, RST and IO0 are good.

I have seen in the forum that many other had similar problem but yet not many have solved..
Please can someone advise me if I did something wrong in the design.

Thanks
Dan
Attachments
DC_ESP32 Pico D4 board_PCB_unfilled.PNG
DC_ESP32 Pico D4 board_PCB_unfilled.PNG (82.89 KiB) Viewed 4650 times
DC_ESP32 Pico D4 board.PNG
DC_ESP32 Pico D4 board.PNG (93.92 KiB) Viewed 4650 times

mspider65
Posts: 4
Joined: Tue Jan 07, 2020 10:12 am

Re: ESP32 Pico D4 Custom PCB not working

Postby mspider65 » Fri Mar 06, 2020 4:35 pm

Did You also received recently the pcb assembled from JLPCB?

dan_jim_23
Posts: 6
Joined: Fri Mar 06, 2020 1:18 pm

Re: ESP32 Pico D4 Custom PCB not working

Postby dan_jim_23 » Fri Mar 06, 2020 8:35 pm

sorry no, I just let it assembly in another factory.
Anyway I'm aware this BGA components aren't easy to solder, but after reading how many have similar problems (no communications on the TX) now I'm wondering if there is a lot of defective chip around..
because I made two boards and no one works.
I still have two others chips and honestly I would like to know if they are working.

but honestly I know I could have made a mistake in the design, for this I hope someone could point out the error.

ESP_Sprite
Posts: 3911
Joined: Thu Nov 26, 2015 4:08 am

Re: ESP32 Pico D4 Custom PCB not working

Postby ESP_Sprite » Mon Mar 09, 2020 10:02 am

Do you get any communication with the ESP32 at all, that is, does the chip send you anything over serial when you reset it?

dan_jim_23
Posts: 6
Joined: Fri Mar 06, 2020 1:18 pm

Re: ESP32 Pico D4 Custom PCB not working

Postby dan_jim_23 » Mon Mar 09, 2020 10:29 am

if you mean on the U0TXD (IO1) unfortunately not, it alwyas stay high (when the other working board which usie the USB-FTDI adapter, sent bytes).
checking on other design I also tried a modification with a pull-up for EN/RST with a 10 k resistor to +3.3V but didn't changed anything
how said I check also the EN/RST line on the scope and this during the upload process goes regularly to 0.

Anyway something is probably wrong with the design, chip or soldering: when I supply the board externally with the 5V I see only 3-4 mA, when I read from datasheet must be ~80 mA.

deandob
Posts: 18
Joined: Sun Dec 02, 2018 5:21 am

Re: ESP32 Pico D4 Custom PCB not working

Postby deandob » Sun Mar 15, 2020 9:27 am

I had a similar problem with the Pico, and solved it by ensuring the decoupling capacitors were placed close to the chip and was very careful with the earth under the chip so that only current destined for the ESP32 was routed via the ground pad, so no other transient current could interfere. My board is working reliably now.

dan_jim_23
Posts: 6
Joined: Fri Mar 06, 2020 1:18 pm

Re: ESP32 Pico D4 Custom PCB not working

Postby dan_jim_23 » Sun Mar 15, 2020 7:01 pm

in the last days I have been able to make some improvements: the chip seems to works (most of the time) and probably the biggest problem was that it has not been soldered correctly.

NiclasH
Posts: 8
Joined: Mon Dec 28, 2015 4:34 am

Re: ESP32 Pico D4 Custom PCB not working

Postby NiclasH » Mon Mar 16, 2020 2:18 am

I have had a similar problem before, and it was due to too much solder paste on the GND under the chip. Using a "checkered" pad resolved the problem. I.e. add solder mask on top of the pad so that you get 9 "islands" of solder paste, or even just make the solder paste layer into such pattern. A good PCB assembly place should probably have spotted this, but mine didn't (nor did I think about it).

jpfaguirre
Posts: 4
Joined: Fri Apr 03, 2020 2:58 pm

Re: ESP32 Pico D4 Custom PCB not working

Postby jpfaguirre » Wed Jun 17, 2020 10:56 pm

mspider65 wrote: Did You also received recently the pcb assembled from JLPCB?
I just received the pcb assembled from JLPCB and I have a similar problem with my ESP32 Pico D4 Custom PCB. Is there a problem with JLPCB?

Who is online

Users browsing this forum: No registered users and 11 guests