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What is ExpressLRS?

ExpressLRS (ELRS) aims to provide the best completely open, high refresh radio control link while maintaining a maximum achievable range at that rate with low latency. Vast support of hardware in both 900 MHz and 2.4 GHz frequencies using the crossfire protocol.

What is voxl-elrs?

voxl-elrs is an application which gives a user the ability to flash a receiver or transmitter, put a receiver into bind mode, and get device information from a receiver.

There is a large array of ELRS compatible receivers and transmitters on the market and we haven’t tested them all, but below is a list of some that we know voxl-elrs supports.

In theory, voxl-elrs supports any receiver that is compatible with ELRS, however some functionalities such as setting a receiver into bind mode may be deprecated since this action requires firmware modifications. Here is a list of currently supported receivers and transmitters:


  • BetaFPV Nano 900MHz


  • iFlight Commando 8


Currently, voxl-elrs does not require any configuration in order to get started. Usage is as follows:

voxl2:/$ voxl-elrs -h
Description: Flash a RX or TX with ELRS firmware.

Usage: voxl-elrs -h -d -w -q -b -v -s

Optional Arguments:
 -h, --help              Show this help message and exit
 -d, --device            Serial port to use for flashing
 -w, --wizard            Activate interactive wizard
 -q, --quiet             Quiet mode, don't print msgs
 -b, --bind              Put receiver in bind mode
 -v, --version           Get receiver version information
 -s, --scan              Scan receiver for firmware information

Argument Descriptions:

  • -h/–help: Show the help message and exit.
  • -d/–device: Specify a specific serial port to use when flashing a receiver or transmitter. By default, this will be set to /dev/ttyUSB0 if flashing a transmitter and /dev/slpi-uart-7 when flashing a receiver through voxl2.
  • -w/–wizard: Activate the interactive wizard that provide user options.
  • -q/–quiet: Quiet mode, don’t print out any messages. Voxl-elrs program will not print out any messages but underlying programs that are called may still print some messages.
  • -b/–bind: Set a receiver that has been flashed with ModalAI firmware into bind mode.
  • -v/–version: Get version information from a receiver. This includes receiver name (Ex: BetaFPV 900RX) and firmware version (Ex:
  • -s/–scan: Scan a connected receiver for firmware information, automatically update to latest firmware if detected version is out of date.


  • The recommended usage of this tool is to use the interactive wizard, by either using voxl-elrs -w or voxl-elrs --wizard and then following the prompt.
  • If you just want to bind a transmitter to your receiver, you can use the voxl-bind-elrs helper utility which will set the receiver into bind mode without having to use the wizard.
    • Note: You cannot set a receiver into bind mode if it is actively connected to a transmitter. Turn the transmitter off and then run either voxl-bind-elrs, voxl-elrs --bind, or run the wizard and follow the prompt for bind mode.
  • If making your own custom modifications to the receiver firmware then be careful using the voxl-elrs --scan function unless you update the firmware version number to be higher than the current ModalAI firmware version ( as of 6/22/2023).
  • You can determine the state of the receiver by inspecting the LED on your receiver and comparing to the information on the ELRS LED Status page.
  • Useful information regarding all things ExpressLRS (ELRS) can be found on the ELRS quickstart page.