ModalAI ELRS Modems

Documentation for ModalAI’s range of ELRS Modems.

M0184 is a 50mW ELRS Gemini Dual 868/915MHz radio targeted for UAS use.

M0193 is a 1W ELRS Gemini Dual 868/915MHz radio targeted for ground side transmitter use.

VOXL Usage

For managing ELRS firmware while connected to a VOXL, please see voxl-elrs.

ELRS Configurator and Building Code

To use ELRS configurator with M0184 and M0193, install Configurator 1.7.8+ https://github.com/ExpressLRS/ExpressLRS-Configurator/releases

Downloading Firmware

To build and flash custom ExpressLRS firmware for the M0184 or M0193, first download the firmware repository. Open a terminal in your desired directory and run:

git clone https://github.com/modalai/ExpressLRS

To get a specific version of the ModalAI firmware, check out the desired tag from the tags list. Tags with a fourth version number include ModalAI’s patches for M0184 and M0193.

Hardware Setup

The ELRS configurator requires a direct connection to your modem in order to flash it. For receiver firmware: either use a USB-UART adapter connected to the TX, RX and GND pins on the modem or connect to a Betaflight FC over USB. For transmitter firmware: connect to the edgeTX USB and select USB Serial (VCP)

Setting Up the Configurator

First, ‘Expert Mode’ must be enabled in the ELRS Configurator’s settings menu.

Next, in the flashing menu, go to the ‘Local’ tab and choose the src directory of the firmware repository you downloaded earlier as the ‘Local path’.

Then, choose ModalAI 900 MHz as the ‘Device Category’ and your modem as the device (ModalAI M0184 RX in this example).

At this point you should configure your firmware options like any other ELRS modem, in either standard or manual mode. Please see the ExpressLRS Configurator Documentation for more information on firmware options.

You should also select the correct flashing option for your hardware setup, either UART (serial) for receivers connected directly to your device with a USB-UART bridge, Betaflight Passthrough for a receiver connected to a Betaflight FC, or EdgeTX Passthrough for an internal transmitter modem.

After selecting the correct serial port, press the Flash button and the Configurator will build and flash your modem.