USB to UART Bridge - Modified for the ESP32-P4 Stamp XL

This program can be flashed on the ESP32-P4 Stamp XL to act as a passthrough to the ESP32-C6 module so that it can be easily flashed with the esptool.

Code modified from https://github.com/espressif/esp-iot-solution/tree/master/examples/usb/device/usb_uart_bridge

Original Readme:

USB to serial bridge tool using the USB and UART capabilities of the ESP32-P4 microcontroller. This tool serves as a debugging and downloading utility with the following features:

1. Bidirectional transparent data communication between USB and UART.
2. Configurable serial port settings (supports baud rates up to 3000000 bps).
3. Compatibility with automatic firmware download functionality for esptool, enabling firmware updates for other ESP SoCs.

Build and Flash

1. Make sure ESP-IDF is setup successfully

2. Set up the ESP-IDF environment variables, please refer Set-up the environment variables, Linux can use:

   . $HOME/esp/esp-idf/export.sh

3. Build, Flash, output log

   idf.py build flash monitor

Automatic Firmware Download with esptool

• The automatic download feature is enabled by default. You can disable this option in menuconfig → USB UART Bridge Demo → Enable auto download.
• When using the automatic download feature, connect the development board's AUTODLD_EN_PIN and AUTODLD_BOOT_PIN pins to the target MCU's IO0 (Boot) and EN (RST) pins respectively.
• The automatic download feature may not function correctly on certain development boards (due to delays caused by RC circuits). In such cases, please fine-tune the code with gpio_set_level software delays.