Receiver

The receiver (RX) is a small module on your drone that receives radio signals from your transmitter and passes the stick/switch data to the flight controller. It’s the other half of your radio link.

Receiver Protocols

The receiver communicates with the FC via a serial protocol:

Protocol	Used By	Connection	Notes
CRSF	ELRS, Crossfire	UART (TX+RX)	Modern standard, fast, bidirectional
SBUS	FrSky	UART (inverted)	Older, still common on legacy gear
IBUS	FlySky	UART	Budget systems
DSM	Spektrum	UART	Less common in FPV now
SPI	Some built-in RX	Direct SPI bus	No external receiver needed

CRSF is the standard for modern builds. If you’re using ELRS or Crossfire, your receiver speaks CRSF to the FC.

Choosing a Receiver

Match your receiver to your transmitter’s protocol:

• ELRS TX module → ELRS receiver: Most popular combo. Open-source, cheap, excellent performance.
• TBS Crossfire TX → Crossfire RX: Proprietary but proven. Being overtaken by ELRS.
• FrSky TX → FrSky RX (SBUS): Legacy. Still works but the ecosystem has stagnated.
• Multi-protocol TX → Various: If your radio has a multi-protocol module, you can use many receiver types.

→ See ExpressLRS for details on the most popular system. → See Protocols for the full protocol landscape.

Receiver Sizing

Size	Use	Examples
Nano/EP	Tiny whoops, micro builds	BetaFPV EP2, Happymodel EP2
Small	Sub-250g, 3” builds	RadioMaster RP2, Matek R24-S
Standard	5” and larger	RadioMaster RP3, Matek R24-D

Nano receivers with ceramic antennas are smallest but have the shortest range. Standard receivers with dipole or T-antennas have the best range.

Installation

Wiring

Receivers typically need 3-4 connections to the FC:

• 5V: Power (from FC’s 5V pad)
• GND: Ground
• TX: Receiver transmit → FC UART RX pad
• RX: Receiver receive → FC UART TX pad (needed for CRSF bidirectional telemetry)

Placement

• Away from the VTX: VTX RF output can interfere with the receiver
• Away from ESCs and power wires: Electrical noise reduces sensitivity
• Antenna positioning: Receiver antennas should be:
  • Extended away from the carbon fiber frame (carbon blocks RF)
  • At roughly 90° to each other (for diversity receivers with two antennas)
  • Secured with TPU tubes or zip ties so they don’t get cut by props

Antenna Routing

For best performance:

• Route antennas to the rear of the frame, pointing up and out
• Keep at least 1-2cm of antenna element past the carbon fiber frame
• Use heat shrink or TPU tubes to protect antenna wires
• Don’t coil excess antenna wire — trim to the correct length or route straight

Binding

Binding pairs your specific transmitter with your specific receiver. Methods:

Binding Phrase (ELRS — Recommended)

Set the same binding phrase in both TX and RX firmware. They auto-connect on power-up. No manual binding process needed. Easiest method.

Button Binding

1. Put the RX into bind mode (hold bind button during power-up, or 3 quick power cycles)
2. Put the TX into bind mode (via menu or Lua script)
3. They detect each other and pair
4. Power cycle both — they should reconnect automatically

Troubleshooting Binding

• Firmware mismatch: TX and RX must be on compatible firmware versions (especially ELRS)
• Wrong protocol: Make sure the TX module protocol matches the receiver
• Antenna issue: If the RX antenna is damaged or disconnected, binding may fail at close range
• Interference: Try binding away from other RF sources (WiFi routers, other transmitters)

Telemetry

Many protocols support telemetry — data sent back from the drone to your radio:

• Battery voltage
• Current draw
• GPS coordinates
• RSSI / Link Quality
• Flight mode

Telemetry appears on your radio’s screen and can be configured as voice alerts (e.g., “battery low” spoken alert when voltage drops).

For CRSF (ELRS/Crossfire), telemetry is bidirectional by default. Configure telemetry sensors in EdgeTX under Model > Telemetry > Discover.