ESP32-S3 Boot loop Issue

[alex6262]

Hi Everyone,
Thanks for your time; I appreciate any help to guide me in the right direction.
I have designed a custom PCB with ESP32-S3 and CP2102N-Axx-xQFN24 as the UDB to UART bridge.
The design includes an external SPI FLASH, which I'm using W25Q128JVSIQ in this case.
The COM port is detected without any issues, and the RX and TX led's flash while I try to connect to the board from Arduino IDE, but I get the following error message:

Code: Select all

esptool.py v4.5.1
Serial port COM18
Connecting......................................

A fatal error occurred: Failed to connect to ESP32-S3: Download mode successfully detected, but getting no sync reply: The serial TX path seems to be down.
For troubleshooting steps visit: https://docs.espressif.com/projects/esptool/en/latest/troubleshooting.html
the selected serial port For troubleshooting steps visit: https://docs.espressif.com/projects/esptool/en/latest/troubleshooting.html
 does not exist or your board is not connected

If I try the "esptool-win64" I get a slightly different error message:

Code: Select all

espefuse.py v4.7.0
Connecting......................................

A fatal error occurred: Failed to connect to Espressif device: Download mode successfully detected, but getting no sync reply: The serial TX path seems to be down.
For troubleshooting steps, visit: https://docs.espressif.com/projects/esptool/en/latest/troubleshooting.html
Please make sure that you have specified the right port with the --port argument.

I have tested my PCB with a multimeter and my RX and TX pins are connected correctly, my SPI Fash is 16MB and the board was assembled by the manufacturer o reduce chance of any soldering issues I might have.

Screenshot_2.png (53.03 KiB) Viewed 17475 times

Screenshot_3.png (23.42 KiB) Viewed 17475 times

Thanks.

Best Regards,
Alex

[ESP_Sprite]

Am I seeing this correctly, are you using the CP2102 as a source of 3.3V? If so, that thing can only supply 100mA, while the ESP32-S3 is specified to require a >=500mA power supply. Could very well be that this is your issue.

[alex6262]

Hi ESP_Sprite,
Thanks for checking the Schematic.
I am only using the CP2102 3.3 output for the RX and TX LEDs are connected to the same chip. The rest of the circuit uses a MIC5216-3.3YM5-TR for power, which is rated at 500MA.

Thanks.
Alex

[alex6262]

After more checking, I found that my SPI_CS0 PIN (32) is high (3.3V) when the board is plugged in.
Checking my Fash datasheet, the CS pin is active low; I'm not sure if ESP32 will manage that internally, pulling it low when required, or if it should be low at all times.

[ESP_Sprite]

That's expected; the ESP32 pulls it low when needed. If you scope it, you should probably see it go low for a few short times when the ESP32 tries to boot.

[htmage]

Hi alex6262, did you find any solution to this problem? I'm having the same problem and struggling with it

[aovtad]

سلام
I have the same problem
I designed a board
I think this error is caused by a hardware problem in soldering

[aovtad]

yes yes yes
i disconnect every thing from my esp and it work