ExpressLRS (ELRS) has revolutionized the FPV radio link. With latency as low as 3ms, range measured in tens of kilometers, and hardware starting under $30, it is no wonder ELRS has become the dominant RC protocol. This guide walks you through setting up ExpressLRS for maximum range and reliability.
Why ExpressLRS?
Before ELRS, long-range RC control meant bulky 900MHz Crossfire or R9 systems. ELRS delivers comparable range on 2.4GHz with antennas small enough for micro quads, or extreme range on 900MHz for dedicated long-range builds.
Key advantages over older protocols:
- Packet rates up to 1000Hz: Lower latency than any competing protocol.
- LoRa modulation: Same spread-spectrum technology used in satellite communications.
- Dynamic power: TX power automatically adjusts from 10mW to 1W based on signal quality.
- WiFi flashing: Update firmware over WiFi — no USB cable needed on the receiver.
Hardware Selection
For Your Radio (TX Module)
If your radio has a module bay (JR bay on Radiomaster, Jumper, FrSky), add a dedicated ELRS module. The HappyModel ES24TX Pro and Radiomaster Ranger are excellent choices at 1W output. Some radios (Radiomaster Boxer ELRS, Jumper T-Pro ELRS) come with ELRS built in.
For Your Drone (Receiver)
- EP1/EP2 (2.4GHz): The standard for 99% of pilots. Range exceeds video range for most setups.
- Diversity receivers (RP3, RP4TD): Two antennas for improved signal reliability. Recommended for long-range.
- 900MHz (R9 receivers): For extreme range beyond 20km. Requires a 900MHz TX module.
Flashing Firmware
ELRS uses the ExpressLRS Configurator (available at expresslrs.org) for firmware management. The process:
- Download ExpressLRS Configurator from the official website.
- Select your TX module and RX target from the device list.
- Set your binding phrase (a shared passphrase that pairs TX and RX automatically).
- Set the regulatory domain for your region (ISM_2400 for 2.4GHz).
- Flash TX via USB or WiFi. Flash RX via WiFi (connect to ExpressLRS RX WiFi network at 10.0.0.1).
Packet Rate and Telemetry Ratio
| Packet Rate | Latency | Range | Best For |
|---|---|---|---|
| 1000Hz | ~3ms | Short | Racing |
| 500Hz | ~5ms | Medium | Freestyle |
| 250Hz | ~9ms | Long | All-around |
| 150Hz | ~14ms | Very Long | Long Range |
| 50Hz | ~32ms | Extreme | Ultra Long Range |
Antenna Placement for Maximum Range
- Keep antennas away from carbon fiber: Carbon blocks RF signals. Mount antennas at least 2cm from any carbon plate.
- TX antenna orientation: Your radio antenna should be vertical. Pointing it at the model creates the worst possible signal.
- Diversity placement: Mount two antennas at 90 degrees to each other.
ExpressLRS is the single biggest upgrade you can make to your FPV setup. Better range, lower latency, and cheaper hardware — there is no downside.