ESP32 Pico D4 trouble flashing

[Syedkhan93]

Hello All,

I have an ESP32 Pico d4 Kit I flash my .bin file through ESP IDE on it, and it works. Once confirmed, I used the same circuit which was on the eval board(Pico Kit) on my custom PCB but now we cannot flash the ESP32.
To mitigate the issue, we try to isolate both IC ESP32 and UART to USB converter(CP2102N).
The Eval board (Pico Kit) is getting flashed so I took out R15 and R16 to isolate CP2102N and connected RXD0 and TXD0 to RX and TX of the eval board of CP2102N (https://www.digikey.com/en/products/det ... 5/15913267). RXD0 goes to TX and TXD0 goes to RX of eval board 5335. the board is not able to flash I made the ESP32 en pin 1 and IO0 low forcefully still we are seeing an error no serial port. The eval board(Pico kit) is already flashed and when we reset the IC using an EN switch it sends data on the serial port as well but when trying to flash it cannot flash.

A fatal error occurred: Failed to connect to ESP32: No serial data was received.
For troubleshooting steps visit: https://docs.espressif.com/projects/esp ... oting.html
CMake Error at run_serial_tool.cmake:56 (message):
python
D:/Software/Espressif/frameworks/esp-idf-v4.4.2/components/esptool_py/esptool/esptool.py
--chip esp32 failed


FAILED: CMakeFiles/flash D:/Software/Espressif/frameworks/esp-idf-v4.4.2/workspace/aws_/aws_working/aws/build/CMakeFiles/flash
cmd.exe /C "cd /D D:\Software\Espressif\frameworks\esp-idf-v4.4.2\components\esptool_py && D:\Software\Espressif\tools\cmake\3.23.1\bin\cmake.exe -D IDF_PATH="D:/Software/Espressif/frameworks/esp-idf-v4.4.2" -D SERIAL_TOOL="python D:/Software/Espressif/frameworks/esp-idf-v4.4.2/components/esptool_py/esptool/esptool.py --chip esp32" -D SERIAL_TOOL_ARGS="--before=default_reset --after=hard_reset write_flash @flash_args" -D WORKING_DIRECTORY="D:/Software/Espressif/frameworks/esp-idf-v4.4.2/workspace/aws_/aws_working/aws/build" -P D:/Software/Espressif/frameworks/esp-idf-v4.4.2/components/esptool_py/run_serial_tool.cmake"
ninja: build stopped: subcommand failed.
ninja failed with exit code 1

[ESP_LJH]

Since the schematic you provide is not complete, I could not see how is the power and where are all GPIOs connected to, but there are still some problems from nets name.
Please check PICO-D4 datasheet or PICO-KIT schemaitc, you could find flash connections are not same with ESP32-WROOM or WROVER. IO16 and IO17 are used, SD_D3 and SD_D2 are available instead.
Second, if GPIO2 is high? Please be noted that to enter into download mode, not only IO0 should be taken care of, you must consider IO0 IO2 and IO12. A suggestion is that use serial tool to see UART0 log first then use download tool. When you could see waiting for download by manually pushing strapping pins into correct states, it means basically your schematic works fine.
Anyway, maybe there are other problems, you could rectify the mentioned errors, if board still could not work, please send me complete schematic of your board and 5335.

[harshaditaliya]

I am using HSPI pins 12,13 and 14 to connect with Sensor and I see the problem flashing code into PICO-D4.
How to isolate IO12 till boot is finished? I am not sure If I have any free pin available to control any transistor or something.