Here is the binding procedure for the F4 Betaflight FC (SPI ExpressLRS Receiver)
This binding procedure could be used for the ELRS F4 1S 5A AIO FC and F4 1S 12A AIO V2.0 FC
There are two ways to bind with the receiver, as shown below
Put the receiver into bind mode using any of these steps:
- "Bind" button in the Betaflight Configurator, Receiver Page (if can't be found, update the Betaflight firmware).
- Using the CLI, type in BIND_RX and press enter once.
- Using the CLI, type in set expresslrs_uid = 0, press enter once, then save and reboot
- Press the bind button on the flight controller.
After the receiver enters the binding state, the receiver indicator on the FC will flash quickly.
At this time, execute ERLS.Lua or (Download Lua File) in the remote control, and then press the BIND button. You can also press the bind button on the remote control or TX module to make TX enter the bind mode. RX and TX will now complete the binding.
Please pay attention to the sequence of binding steps. First make RX enter binding mode and then TX.
The binding phrase is hashed into 6 bytes represented as numbers. These 6 bytes are referred to as the UID bytes. UID bytes are entered into the Betaflight CLI for binding. When building via ExpressLRS Configurator or via VS Code, note down the UID bytes from the build log.
Setting Binding Phrase
The following commands need to be executed in the betaflight cli:
set expresslrs_uid = [ Your UID bytes ]
After completing the phrase binding settings, the binding will be automatically completed after the receiver and remote control startup.
RF Mode Adjustment
These AIOs with ExpressLRS SPI Receivers are set to use 500Hz as default. To adjust it, you will need to go into Betaflight CLI and use the following commands:
set expresslrs_rate_index = [your index]
Where [your index] corresponds to the following :
- 500Hz = 0
- 250Hz = 1
- 150Hz = 2
- 50Hz = 3
For example, if I want to switch the refresh rate to 250Hz, I need to execute these commands in betaflight cli:
set expresslrs_rate_index = 1
ExpressLRS 1.x.x or ExpressLRS 2.x.x
ExpressLRS 1.x.x TX only works with Betaflight firmware for ExpressLRS 1.x.x, and upgrading the transmitter to ExpressLRS 2.x.x means flashing the flight controller with a different Betaflight version. If upgrading minor versions, such as from ExpressLRS 1.1.0 to 1.2.0 on the transmitter, no changes to the flight controller are needed although there may be bug fixes to the ExpressLRS Betaflight implementation as well.