I remember doing this for NyBoard, but having challenges with BiBoard: I get the following output and error. I know it's the right port. Try sudo and get the same error. This is MacOS Sequoia 15.3 $ esptool.py -b 115200 --port /dev/tty.usbmodem58CF0756171 read_flash 0x000000 0x400000 flash_4M.bin
esptool.py v4.8.1
Serial port /dev/tty.usbmodem58CF0756171
Connecting....
Detecting chip type... Unsupported detection protocol, switching and trying again...
Connecting.....
Detecting chip type... ESP32
Chip is ESP32-U4WDH (revision v3.1)
Features: WiFi, BT, Dual Core, 240MHz, Embedded Flash, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz
MAC: a0:dd:6c:23:57:70
Uploading stub...
A fatal error occurred: Failed to write to target RAM (result was 01070000: Operation timed out)
Could you take a screenshot of your Esp32's settings?