# A UART to network bridge for ESP32 ![](../../uart-bridge/screenshots/dashboard.png) - See detailed tutorial at https://mongoose.ws/tutorials/esp32/uart-bridge/ ## Flash pre-built firmware You can flash a pre-built firmware to the ESP32 device using the following instructions: 1. Connect your ESP32 device to the workstation. It should be accessible via a serial port 2. Download and unzip ESP32 flashing tool from https://mongoose.ws/downloads/esputil.zip 3. Download a prebuilt firmware https://mongoose.ws/downloads/uart-bridge.hex into the unzipped directory 4. 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.
```sh
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`:
```sh
esputil -p COMPORT -fp 0x220 flash uart-bridge.hex
```
For more on possible options for flash parameters, see
https://github.com/cpq/esputil#flash-parameters