ESP32 WiFi telemetry¶
The ESP32 are readily available Wi-Fi modules with full TCP/IP stack and microcontroller capability. They offer dedicated UART, SPI and I2C interfaces. They can be used with any ArduPilot autopilot controller.
DroneBridge for ESP32¶
Almost every ESP32 development board is capable to run DroneBridge for ESP32. Boards and modules with an external antenna connector are recommended, since those will offer more range.
Most modules support 3.3V input (only), while some autopilots serial ports provide only 5V . You will need to check compatibility and step down the voltage if needed. It is not generally recommended to use the autopilot’s 3.3V supply unless you are certain it can provide enough current for the ESP32 board you are using.
Some examples for modules and DevKits that accept 3.3V supply:
AZDelivery DevKit C
Adafruit AirLift – ESP32 WiFi Co-Processor Breakout Board (requires FTDI adapter for flashing firmware)
Adafruit HUZZAH32 (requires FTDI adapter for flashing firmware)
ESP32-WROOM-32UE (module only - requires custom PCB)
ESP32-WROOM-32E (module only - requires custom PCB)
NodeMCU style DevKit Boards with an IPEX port for an external antenna often also offer an onboard antenna that is activated by default. You may need to re-solder a resistor to activate the external antenna port.
Downloading and Flashing the Firmware¶
Follow the flashing instructions inside the GitHub Repository. The exact parameters may differ from release to release of DroneBridge for ESP32.
For convenience reasons some short instructions are given here:
Connect your DEVKit to your computer via USB/Serial bridge (most DevKits already offer a USB port for flashing and debugging)
Erase the flash and flash the DroneBridge for ESP32 firmware onto your ESP32
Using Espressif Flash Download Tool (Windows only)
Using esp-idf/esptool (all platforms)
Power Cycle the ESP32
Connect to the “DroneBridge for ESP32” WiFi network and configure the firmware for your application
Configuring DroneBridge for ESP32¶
You can change the default configuration via the Webinterface.
Connect to the ESP32 via WiFi and enter
192.168.2.1 in the address
bar of your browser.
DroneBridge for ESP32
UART baud rate
UART TX pin
UART RX pin
Custom Settings & Webinterface¶
192.168.2.1 in the address bar of
Some settings require you to reboot the ESP32 to take effect.
Wiring is very simple and mostly the same for all devices connected to any serial port (eg TELEM1 or TELEM2) of the autopilot. This guide does not go into detail here, but provides an outline for wiring below.
Connect UART of ESP32 to a UART of your autopilot (e.g. TELEM 1 or TELEM 2 port). Make sure the voltage levels match! Most ESP32 DevKits can only take 3.3V!
TX to RX
RX to TX
GND to GND
Stable 3.3V or 5V power supply to the ESP32 (depending on the available inputs of your DevKit and capabilities of the autopilot)
Set the autopilot port to MAVLINK 1 or 2 protocol.
Some manufacturers of ESP32 DevKits have wrong labels for the pins on their products. Make sure that the PINs on your board are labeled correctly if you encounter issues.
Make sure to always follow the instructions of the ESP32 board manufacturer when it comes to wiring. Especially the power supply.
Configure the UART of the autopilot that is wired to the ESP32. The default configuration of DroneBridge is:
Protocol: MAVLink (v1 or v2)
Baudrate: 115200 baud
If connected to Serial2 these parameters should be set on the autopilot (if using another serial port, replace the “2” in the parameter name with the serial port’s number):
If you have problems connecting, it may help to set BRD_SER2_RTSCTS = 0 to disable flow control although this is not normally necessary
Connecting to the GCS¶
The following connection options are available:
UDP unicast on port
14550to all connected devices.
TCP on port
DroneBridge for ESP32 will automatically forward all data to all connected WiFi devices via UDP to port 14550. QGroundControl or Mission Planner should auto-detect the connection and no further actions should be necessary.
Always erase the flash of the ESP32 before flashing a new release/firmware
Check if the pins on your ESP board are labeled correctly.
Enter the IP address in your browsers address bar
http://192.168.2.1. No https supported! You may need to disconnect from the cellular network when using a phone to be able to access the webinterface.
If your network is operating in the same IP range as DB for ESP32 you need to change the Gateway IP address in the Webinterface to something like
DroneBridge for ESP32 offers a REST:API that allows you to read and write configuration options. You are not limited to the options presented by the Webinterface (e.g. baud rates). You can use the API to set custom baud rates or to integrate the system into your own setup.
To request the settings
To request stats
Trigger a reboot
Trigger a settings change: Send a valid JSON
"wifi_ssid": "DroneBridge ESP32",