Strange behavior with ground

[rickwise]

This issue is with an ESP32 camera board. I made a PCB to use as a carrier/power interface.

There are three pins marked "GND", and I connected them all together and to the ground of the power input, and it won't boot.

The pins on my camera board are (CCW from 5V):
5V GND IO12 IO13 IO15 IO14 IO2 IO4 /other header/ GND IO1 IO3 VOUT GND IO0 IO16 3V3

The three GND pins show no resistance (< 0.001 ohm) between each other.

The board won't boot when connected to the PCB, but if I feed power directly to the 5V pin and the GND pin next to it, it's fine. To find the problem, I started connecting one pin at a time. It works when the GND between IO0 and VOUT is connected. But when I connect the ground at the end of that header (beyond IO1), it won't boot.

[ESP_LJH]

Could you show me the picture of the board you use, let us make sure if GND is GND. Of if you have PCB files, you could check it, too.

[rickwise]

This is the camera board:

CAM.jpg (456.95 KiB) Viewed 6714 times

And this is the PCB board file:

CAM_board.JPG (75.09 KiB) Viewed 6714 times

[mbratch]

Can you show a schematic for your base board?
When you successfully powered the esp32-CAM separately, do you connect all of its grounds together in that test? If that works then there's something wrong with the base board.

[rickwise]

ESP32CAM_Basic_v0.2.png (11.81 KiB) Viewed 6622 times

Schematic above.

I made by own device in Eagle, and I didn't do a good job on the schematic footprint, but you can see the pin labels on the outside of the device outline. The order of pins in the schematic footprint is the same as the board viewed from above with the SD card at the top.

With the ESP32CAM not plugged into the board, if I connect +5 between 5V and GND1, it works fine. If I connect GND1 to either GND2 or GND3, it doesn't boot.

FYI, X1 is a two-row header. I jump the pins to ground, and read them to set vflip and hflip and to choose one of 4 resolutions.

I cut the traces to GND2 and GND3 on the board, and it workswhen plugged into the board. Setting vflip, hflip, and resolution using the jumpers works. I'm using it that way, but I'd like to understand what I'm doing wrong in connecting the 3 grounds.

[mbratch]

With the ESP32CAM not plugged into the board, if I connect +5 between 5V and GND1, it works fine. If I connect GND1 to either GND2 or GND3, it doesn't boot.

To make sure I'm understanding you, you are saying that without your pcn, if you just power the ESP32-CAM and connect all of its grounds together, then the ESP32-CAM won't boot?

[ESP_LJH]

As you describe, it is really werird. Since ESP32-CAM is not designed by us, I have no board to test. But from their website, three grounds should be the same. How many boards do you test? Do you test the connectivity of three GND with independent ESP32-CAM, with ESP32-CAM + base board? How your base board provide 5 V power? What is the output capacity?

[roygun]

Yes if GND3 is connected to ground it will not boot. Took a while to resolve this problem and lots of frustration.
I always suspect modules bought from Amazon, they could be designed and manufactured as a copy from originals and not know the whole story.

BR

RonnyG

[dcweng]

I got the same issue. I was using only the GND3 pin, and it's not consistent. Sometimes it boots correct, the other time it keeps restarting. My has about 10k resistant to the other two ground pins. When I connected all three to ground, it keeps restarting like brownout issue. It only works when the GND3 is not connected. This board has additional two sets connections at the VCC voltage selector, compared to my other ESP32-cam. The additional connectors are connected to the GND3, but I can't find where is this goes. The marking of the GND3 pin also says GND/R not just GND. I'll just not connecting anything to the GND3 for now.

[ESP_Sprite]

It's not the first time someone copied a board and mis-read the silkscreen for CMD as GND... perhaps that happened.