Can't read chip ID on ESP32-S3-WROOM-1

[ktowers]

I've designed a custom board using the ESP32-S3-WROOM-1 module. I've added the exact circuit using the CP2102 USB/UART interface.

esptool.py trace has the following output:

Code: Select all

C:\work\t_baro>esptool.py --trace chip_id
esptool.py v4.8.1
Found 1 serial ports
Serial port COM4
Connecting...TRACE +0.000 command op=0x08 data len=36 wait_response=1 timeout=0.100 data=
    0707122055555555 5555555555555555 | ... UUUUUUUUUUUU
    5555555555555555 5555555555555555 | UUUUUUUUUUUUUUUU
    55555555                          | UUUU
TRACE +0.000 Write 46 bytes:
    c000082400000000 0007071220555555 | ...$........ UUU
    5555555555555555 5555555555555555 | UUUUUUUUUUUUUUUU
    5555555555555555 5555555555c0     | UUUUUUUUUUUUU.
TRACE +0.005 Read 1 bytes: 45
TRACE +0.000 Read invalid data: 45
TRACE +0.001 Remaining data in serial buffer:
    53502d524f4d3a65 7370333273332d32 | SP-ROM:esp32s3-2
    303231303332370d 0a               | 0210327..
.TRACE +0.054 command op=0x08 data len=36 wait_response=1 timeout=0.100 data=
    0707122055555555 5555555555555555 | ... UUUUUUUUUUUU
    5555555555555555 5555555555555555 | UUUUUUUUUUUUUUUU
    55555555                          | UUUU
TRACE +0.000 Write 46 bytes:
    c000082400000000 0007071220555555 | ...$........ UUU
    5555555555555555 5555555555555555 | UUUUUUUUUUUUUUUU
    5555555555555555 5555555555c0     | UUUUUUUUUUUUU.
TRACE +0.122 No serial data received.

You can see that the ESP32 module is transmitting a string "SP-ROM:esp32s3-20210327", so the communication seems to be working.

I've confirmed that EN# and IO0 are initially driven low for about 150 mSec prior to the serial data coming out.

It doesn't look like the ESP32 module is actually getting into bootloader mode. The only other strapping pin mentioned in docs (GPIO46) is floating.

How does the ESP32 determine which port UART or USB it will use for bootloader commands? Does it watch both ports or is there some hard strapping needed? Can anyone confirm whether the string output by my ESP32 module comes from the booloader mode?

Thanks

Kevin

[ESP_Sprite]

It uses both of them. Can you validate your circuit by tying GPIO0 to ground while trying to program the chip? Also, "I've added the exact circuit" doesn't really help when we don't know what "the exact circuit" is.

[ktowers]

I found my problem. I have two power supplies that eventually feed the power to the ESP module. There is too much bulk capacitance on the power lines when powered from USB on my PCB. This results in the ESP not seeing the requisite reset state because the 1uF cap on the EN# line charges at almost the same rate as Vcc.

Thanks for your help

Kevin