This page aims to explain which options to set on the ExpressLRS Configurator for a particular Hardware. It helps guide you through which options you should enable for your purposes or which options should be left at default.
Some of these options are present on both the Tx and Rx Targets. It is important that these options match to both the TX module and receiver in order for them to bind.
team900 also share a few options and some options are unique to that frequency band. Shown below are common options available on
team900 TXes respectively.
Regulatory_Domain_AU_915 Regulatory_Domain_EU_868 Regulatory_Domain_FCC_915 Regulatory_Domain_ISM_2400
EU 868is compliant to the frequency but is not LBT compliant 👂 . Every other band is near compliant 👿 but may not be fully compliant for your regulatory domain.
This step is simple but important. Both the TX and RX NEED to have the same binding phrase or ExpressLRS WILL NOT WORK. Anyone using the same binding phrase as you will be able to control your model, so be unique. Set something memorable, and limit to alphanumeric phrases conforming to the Latin alphabet. Receivers flashed with firmware builds that do not have binding phrase enabled will support and require the traditional binding method. 📜
AUX1 is the channel ExpressLRS uses to detect "ARMED", and this feature assumes that a low value of the arm switch is disarmed, and a high value is armed. OpenTX can invert your switch if you prefer it to be mechanically inverted. It may be best not to enable no sync on arm when you are first setting up ExpressLRS as it can be a source of confusion.
HYBRID_SWITCHES_8changes this to 1x 2-pos + 6x 7-pos + 1x 16-pos, with only the 2-position being low-latency. In Normal Mode, all switches are sent with every packet; while in Hybrid Mode, only AUX1 is sent with every packet and the rest are rotated through. Note: The switch mode MUST match between the TX and RX. A detailed explanation of the differences between the two options can be found in the Switch Modes page.
Note 1: Increase the telemetry rate with the ExpressLRS lua script. Increase the rate until the sensor lost warnings go away. It is normal to set it up to 1:16 with a 200 Hz refresh rate.
Note 2: It must be enabled together with HYBRID_SWITCHES_8.
With this unchecked/disabled, you will only get the basic RC Link Telemetry like 1RRS (RSSI dbm), RQLY (LQ) etc.
Tip. You can have this option enabled in the Firmware Configuration, but set TLM Ratio to OFF in the ELRS Lua Script when you don't need advanced telemetry (like when racing). Should you need the telemetry (freestyle or medium-to-long-range flying), flip TLM Ratio back to your favorite ratio, like 1:16 or 1:8.
Default value is 320LU. If you want to change that you have to suffix your milliseconds value with LU. For example, in order to specify 100 ms telemetry update rate you have to enter it like this: 100LU.
Typically, you want to keep 320LU value for OpenTX based radios, and 100LU for ErskyTx ones.
Tip: only check this if you're changing the value. No need to enable it if you'll be using the default 320LU value
JUST_BEEP_ONCE DISABLE_STARTUP_BEEP MY_STARTUP_MELODY="<music string>|<bpm>|<semitone offset>"
For all your customization needs, use
MY_STARTUP_MELODY to define your own startup melody using either the BlHeli32 syntax or RTTL. The BlHeli32 Synatax has the required parameters
music string and
semitone offset is optional to transpose the entire melody up or down by the defined amount of semitones. Example BlHeli32 melodies are available on Rox Wolfs youtube channel, some experimentation may be required though. To write your own melody, this (Sheet Music 101) and this (BLHeli Piano) are useful resources.
The RTTL Syntax is the same as used in old mobil phones for ringtones and some examples of it can be found here, where you can search through many existing RTTL melodies.
Receiver Only Options¶
Note: Configuration of the Receivers should match the configuration of the Transmitter Module for Sync/Binding to happen between devices.
The explanation of the options for the Transmitter Modules also apply for the Receivers.
But here's a few Receiver-specific Options you can configure:
For a complete list of User Defines, head over to the User Defines page.
Done! It's time to flash the firmware on your transmitter