https://docs.espressif.com/projects/esp-at/en/latest/AT_Binary_Lists/ESP32_AT_binaries.html

pip3 install esptool

navigate into folder and run

• macosx

  esptool.py --chip auto --port /dev/tty.usbserial-14430 --baud 115200 --before default_reset --after hard_reset write_flash -z download.config

  esptool.py --chip auto --port /dev/tty.usbserial-14430 --baud 115200 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size 4MB 0x8000 partition_table/partition-table.bin 0x10000 ota_data_initial.bin 0xf000 phy_init_data.bin 0x1000 bootloader/bootloader.bin 0x100000 esp-at.bin 0x20000 at_customize.bin 0x24000 customized_partitions/server_cert.bin 0x39500 customized_partitions/mqtt_key.bin 0x26000 customized_partitions/server_key.bin 0x28000 customized_partitions/server_ca.bin 0x2e000 customized_partitions/client_ca.bin 0x30000 customized_partitions/factory_param.bin 0x21000 customized_partitions/ble_data.bin 0x3B000 customized_partitions/mqtt_ca.bin 0x37000 customized_partitions/mqtt_cert.bin 0x2a000 customized_partitions/client_cert.bin 0x2c000 customized_partitions/client_key.bin

• References https://docs.espressif.com/projects/esp-at/en/latest/Get_Started/Downloading_guide.html

You need to connect an external USB to UART converter, because the UART0 which is connected to the internal USB of esp32 Wroom it is used by the firmware as a debugger. It is possibile to modify the firmware to map all the AT communication to the UART0 and avoid the debugging. However here we won't show it how.

• UART1 AT command/response ESP32 USB to Serial Converter GPIO16 (RX) TX Orange GPIO17 (TX) RX Yellow GPIO15 (CTS) RTS GPIO14 (RTS) CTS USB to serial converter TX RX RTS CTS

• UART0 (for reference) UART0 PC GPIO3 (RX) TX GPIO1 (TX) RX