To create the dump
First we enter bootloader mode
pin 23 to gnd pin 9 to gnd disconnect pin 9 disconnect pin 23
after run esptool --chip esp32 --port /dev/ttyACM0 read_flash 0x000000 0x400000 esp32_dump.bin
esptool --chip esp32 --port /dev/ttyACM0 read_flash 0x000000 0x400000 esp32_dump.bin