ESP32 Forum

Hi!

Is it possible to use ESP-AT with only 1 UART connection?

For example, we will flash the ESP32-U4WDH with the UART0, and then use this UART to send AT commands. When we want to upgrade ESP32 firmware, we can use BOOT pins to force it into bootloader and then flash it with UART0.

We need a solution that supports WiFi and BLE over a single serial connection to the host MCU.

Kind regards,
Filip

It is possible to use ESP-AT using only UART0 connection. You can change the AT command port (UART1) to UART0:
Method 1: Please refer to https://docs.espressif.com/projects/esp ... -port-pins, then if you want to upgrade the ESP32 firmware, you can use AT+USEROTA command OTA to upgrade ESP32 firmware.
Method 2: You can modify factory_param.bin through the https://github.com/espressif/esp-at/blo ... ools/at.py (You can view the relevant configuration through python tools/at.py -h and python tools/at.py modify_bin -h. ) file to replace factory_param.bin in the AT firmware. Afterwards, if you want to upgrade the ESP32 firmware, you can use AT+CIUPDATE or AT+USEROTA command to perform OTA upgrade.
Regarding the upgrade method you mentioned, use the BOOT pin to force into the bootloader,and then flash it with UART0. You can read the official technical manual of ESP32-U4WDH first. If you need technical support, you can consult the ESP-IDF team.