A UART to network bridge for ESP32

This example is a demonstration of how Mongoose Library could be integrated into an embedded device and provide a UART-to-Network bridge capability:

A device opens listening TCP port and Websocket port and waits for connections
When a client connects, data is exchanged with the device's UART
Everything that client send, is sent to the UART
Everything that is read from the UART, gets sent to the client
Multiple clients are allowed
Live UART console allows to talk to the UART from the web page
Web UI is hardcoded into the binary and does not need a filesystem

Screenshots

Build and flash

Build requires Docker installed, and uses Espressif's ESP-IDF docker image:

make build
make flash PORT=/dev/YOURSERIAL

Flash pre-built firmware

You can flash a pre-built firmware to the ESP32 device using the following instructions:

Connect your ESP32 device to the workstation. It should be accessible via a serial port
Download and unzip ESP32 flashing tool from https://mongoose.ws/downloads/esputil.zip
Download a prebuilt firmware https://mongoose.ws/downloads/uart-bridge.hex into the unzipped directory
Start command prompt (or terminal on Mac/Linux). Run cd PATH/TO/esputil to go into the unzipped esputil/ directory. After that, run the following command (change COMPORT to the board's serial port):

OS	Command
Windows	`.\windows\esputil -p COMPORT flash uart-bridge.hex`
Linux	`./linux/esputil -p COMPORT flash uart-bridge.hex`
MacOS	`./macos/esputil -p COMPORT flash uart-bridge.hex`

Next step is to monitor and follow the instructions.

esputil -p COMPORT monitor

Note: if monitor command shows constant restarts, the flash parameters settings can be wrong. Reflash your device with -fp ... flash parameters settings. For example, WROOM-32 based boards use -fp 0x220:

esputil -p COMPORT -fp 0x220 flash uart-bridge.hex

For more on possible options for flash parameters, see https://github.com/cpq/mdk#flash-parameters