Happymodel EP2 RX — ELRS 2.4GHz Nano Receiver | SX1280 | ESP8285 | SMD Ceramic Antenna | 0.44g | 10×10mm | CRSF
The Lightest ELRS Receiver You Can Buy — 0.44 Grams, 10×10mm, Zero Compromises on Link Quality.
The Happymodel EP2 is one of the smallest and lightest ExpressLRS 2.4GHz receivers ever made. At 0.44 grams and 10×10×6mm, it disappears into any build — whoops, micro quads, fixed wings, anything where weight and board space are at a premium. It uses the same SX1280 RF chip as full-size ELRS receivers and delivers the same low-latency, high-refresh-rate link quality in a package most receivers can't touch for size.
📡 RF Hardware — SX1280 + ESP8285
The EP2 is built around the Semtech SX1280IMLTRT RF transceiver — the same chip used across the ELRS ecosystem — paired with an ESP8285 MCU for open-source firmware support and WiFi-based firmware updating. The SMD ceramic antenna is integrated directly onto the board (no external antenna wire to break or snag), with a peak gain of 3.7dB — higher than the EP1's omnidirectional antenna at 2.23dB.
Key specs at a glance:
- RF chip: SX1280IMLTRT
- MCU: ESP8285
- Antenna: SMD ceramic, integrated, 3.7dB peak gain
- Frequency: 2400–2500MHz (ISM band)
- Refresh rate: 25Hz to 500Hz
- Protocol: CRSF (Crossfire Serial)
- Working voltage: 5V
- Weight: 0.44g
- Dimensions: 10mm × 10mm × 6mm
📶 WiFi Firmware Updates — No Tools Required
Unlike STM32-based receivers that require a programmer to update firmware, the EP2's ESP8285 MCU supports over-the-air WiFi firmware flashing. Power it on, wait for the fast LED blink indicating WiFi hotspot mode, connect to the EP2's network at 10.0.0.1 (password: expresslrs), and flash new firmware directly from your browser. No ST-Link, no USB passthrough, no soldering.
🔗 Binding & LED Status
Binding is a simple 3-power-cycle procedure:
- Power on the EP2, wait for the LED to go off, power off
- Repeat twice more — on the third power-up the LED will double-flash, indicating bind mode
- Activate bind on your transmitter via the ELRS LUA script — LED goes solid when bound
LED meanings at a glance:
- Solid → bound and connected
- Double-flash → bind mode
- Slow flash → no TX signal
- Fast flash → WiFi hotspot active
⚠️ Compatibility Notes
- Compatible with any ELRS 2.4GHz transmitter running matching firmware (RadioMaster, BetaFPV, Happymodel ES24TX, etc.)
- Uses CRSF protocol — connect to any UART on your FC configured for Serial RX / CRSF
- This is the EP2 variant — ceramic SMD antenna, no external UFL connector. If you need an external T-antenna or UFL, look at the EP1 variant instead
- Firmware updates available via ExpressLRS Configurator — WiFi flashing supported
- Not ELRS V3 hardware — compatible up to ELRS 3.x firmware on ESP8285 targets; check ELRS release notes for your version's ESP8285 support status before updating
📦 What's in the Box
- 1× Happymodel EP2 RX receiver
- Pre-soldered pads for 5V, GND, TX, RX
No antenna wire, no connector — just the bare board. Solder directly to your FC pads.
