How to Pair a Radio and ELRS Receiver for FPV Drones
Pair an ExpressLRS receiver with a radio that has an ELRS module on the same band. A 2.4GHz receiver needs a 2.4GHz module, and a 900MHz receiver needs a 900MHz module. Wire the receiver to a flight controller UART with CRSF, set the same binding phrase on both ends, and confirm a solid LED before arming.
Quick facts
| Fact | Value |
|---|---|
| Receiver protocol | CRSF over a UART |
| RP1 refresh rate | 500Hz, or F1000Hz in full rate mode |
| EP1 weight | 0.41g, 10 by 10mm |
| ES900 module band | 915MHz or 868MHz |
| ER4 channels | 4 PWM channels, 10mW telemetry |
| Lowest price receiver here | $18.57 for the HPXGRC ELRS receiver |
Do you need a radio with ELRS built in, or an external module?
Some radios ship with an internal ELRS module. That is the simplest start because no module bay is used.
Other radios take an external module in a JR or Nano bay. The ES900TX module fits TX16S, T12, and T18 radios for 900MHz long range.
An external module also lets you switch bands. Swap a 2.4GHz module for a 900MHz module without buying a new radio.
Should you pick a CRSF or a PWM receiver?
Pick CRSF for any FPV drone with a flight controller. CRSF carries all channels plus telemetry over one UART.
Pick PWM for a plane or car without a flight controller. PWM wires each channel straight to a servo.
The ER4 is a PWM receiver with 4 channels. The EP1 and RP1 are CRSF receivers for flight controller builds.
How do you wire the receiver to the flight controller?
Connect receiver TX to flight controller RX, and receiver RX to flight controller TX. Add 5V and ground.
Enable Serial RX on that UART in Betaflight. Set receiver mode to Serial and the provider to CRSF.
CRSF needs a full duplex UART. Check that serialrx_inverted and serialrx_halfduplex are off, then save and reboot.
How do you bind the pair and check the link?
Flash the module and receiver with the same binding phrase and the same major firmware version.
Power the radio first, then the receiver. A solid LED and a C in the Lua script confirm the link.
Open the Betaflight Receiver tab and move every stick. Confirm each channel moves in the right direction before arming.
What packet rate should you run?
Run 500Hz for racing and freestyle. It sends a packet every 2ms for a responsive feel.
Run 100Hz or lower for long range cruising. Slower rates carry more error correction per packet.
The RP1 and RP2 reach 500Hz, or F1000Hz in full rate mode. The EP1 runs 25 to 500Hz.
What failsafe setting should you use?
Set failsafe to cut throttle on signal loss. A quad that holds throttle will fly away.
Test failsafe with props off. Switch the radio off and confirm Betaflight shows failsafe before you fly.
ExpressLRS reports link quality on your OSD. Watch LQ fall before RSSI falls, and turn back early.
How the options compare
| Part | Type | Band / Protocol | Key spec | Price |
|---|---|---|---|---|
| FlySky FS-i6X | Radio | AFHDS 2A | 6 to 10 channels | $32.99 |
| HPXGRC ELRS | Receiver | 2.4GHz ELRS | CRSF serial | $18.57 |
| HappyModel EP1 | Receiver | 2.4GHz ELRS | 0.41g nano | $31.50 |
| ES900TX/RX | Module set | 915 / 868MHz | Long range | $38.05 |
| RadioMaster ER4 | Receiver | 2.4GHz ELRS | 4CH PWM | $53.99 |
| RadioMaster RP1 V2 | Receiver | 2.4GHz ELRS | 500Hz CRSF | $58.99 |
How do you set up a new ELRS pair from scratch?
- Mount the receiver and wire TX, RX, 5V, and ground to a free UART.
- Enable Serial RX on that UART and set the provider to CRSF in Betaflight.
- Flash the module and receiver with the same binding phrase and major version.
- Power the radio, then the receiver, and confirm a solid LED.
- Check all channels in Betaflight, set failsafe, and test with props off.
Parts that fit this guide
Prices below are the live store prices we verified on November 10, 2026. In-stock parts ship from New York in 1 to 2 business days. Check the product page for the current price before you order.
FS-i6X 10CH 2.4GHz AFHDS 2A RC Transmitter with Receiver Options ($32.99)
Stick radio at $32.99. Six channels by default, expandable to 10, on AFHDS 2A.
2.4G ExpressLRS ELRS Receiver for FPV Freestyle Long Range Drones ($18.57)
Lowest price ELRS receiver here at $18.57 for freestyle and long range builds.
HappyModel EP1 TCXO 2.4GHz ELRS Receiver, Ultra Light 0.41g, 10x10mm, 25Hz~500Hz Refresh Rate ($31.50)
Nano receiver at $31.50. It weighs 0.41g, measures 10 by 10mm, and runs 25 to 500Hz.
ExpressLRS ES900TX ES900RX Long Range Module 915/868MHz for TX16S T12 T18 ($38.05)
Module and receiver set at $38.05 for 915 or 868MHz long range on TX16S, T12, and T18.
ER4 2.4GHz ExpressLRS PWM Receiver, 4CH, 10mW ($53.99)
PWM receiver at $53.99. Four channels drive servos directly with 10mW telemetry.
RadioMaster RP1 V2 ELRS Nano Receiver 2.4GHz CRSF 500Hz With 65mm UFL T Antenna For TX16S TX12 Boxer Zorro FPV Drone RC RX Kit ($58.99)
Nano receiver at $58.99 with a 65mm T antenna and 500Hz refresh rate.
Shop the full range: ELRS Receivers at Quality RC Parts. See also: Related guide.
Frequently asked questions
Can I use a FlySky FS-i6X radio with an ELRS receiver?
Not directly. The FS-i6X speaks AFHDS 2A, so it needs an external ELRS module in its bay to drive an ELRS receiver.
What is the difference between ELRS and Crossfire?
Both use CRSF to talk to the flight controller. ELRS is open source with higher packet rates, while Crossfire is a closed TBS system.
Why does my receiver enter WiFi mode on power up?
It enters WiFi mode after 60 seconds with no link. Connect to its ExpressLRS RX hotspot at 10.0.0.1 to flash or set options.
Do I need a 900MHz module for long range FPV?
No, but it helps. A 900MHz link penetrates better at distance, while 2.4GHz suits racing with faster packet rates.
Sources
- RadioMaster RP1 and RP2 receiver manual
- HappyModel EP2 TCXO receiver manual
- ExpressLRS binding guide (iFlight)
- ExpressLRS web flasher
Last updated: November 10, 2026.
