File 03 · ELRS ReceiverAlpha
An ExpressLRS receiver, open from antenna to firmware.
OSHWA certifiedModel· pick your build
What does this do?
A receiver has one job: get your commands off the air and hand them to the flight controller. OpenRX runs ExpressLRS, which uses LoRa modulation: the signal is a frequency chirp. That is why a receiver this small, but still holds a link kilometres out while Wi-Fi on the same 2.4 GHz band dies across the house. It speaks CRSF to the flight controller over one UART wire, is powered from a 5V pad, and flashes over Wi-Fi or Betaflight passthrough. Four variants, from ceramic antenna Lite to dual-radio Gemini.
See how the whole drone works →Published so you can study it. Produced so you don't have to.
Teardown
- SX1281 · 2.4 GHz LoRa radio×1
- ESP32-C3 · MCU×1
- 2.4 GHz band-pass filter×1
- ELRS link antenna×1
- Wi-Fi antenna×1
- 52 MHz TCXO×1
- TLV75533 · 3.3 V LDO×1
- WS2812B · RGB status LED×1
- Solder pads, boot pad×1
Every spec, one table
- Band
- 2.4 GHz
- Radio
- SX1281
- Antenna
- On-board ceramic
- Telemetry power
- 13 dBm (20 mW)
- Protocol
- CRSF
- MCU
- ESP32-C3
- Input
- 5 V pad
- Firmware
- ExpressLRS
- Flashing
- Betaflight passthrough or Wi-Fi
- Dimensions
- 10.0 × 11.5 mm
- PCB
- 6-layer, 1.0 mm
In the box
- 1×OpenRX board
- 1×Sillicone cables
- 1×Heat-shrink sleeve + double-sided tape
- 1×Quickstart guide
Provenance
- DesignedLeuven, Belgium
- AssembledShenzhen, China
- NextEU assembly
The firmware this board runs on
ExpressLRS is community firmware we didn't write, and it is what makes this board fly.
Developed by these people
Manufacturer & safety information
Incutec BV, Stapelhuisstraat 15, 3000 Leuven, Belgium · contact@opendrone.be · KBO/BCE 1038.934.039 · EU Declaration of Conformity
Product type: OpenRX · SKU OPENRX-LITE
- Not a toy. Not for persons under 14; minors only under adult supervision.
- Component for self-built unmanned aircraft: the builder is responsible for the assembled aircraft and its lawful operation.
- LiPo batteries can ignite when damaged, shorted or overcharged; never charge unattended.
- Remove propellers before bench testing, configuration or firmware updates.
- Observe the voltage and current limits in the specifications; reverse polarity destroys the board.
- Geen speelgoed. Niet voor personen onder 14 jaar; minderjarigen alleen onder toezicht van een volwassene.
- Component voor zelfgebouwde onbemande luchtvaartuigen: de bouwer is verantwoordelijk voor het samengestelde toestel en het wettige gebruik ervan.
- LiPo-batterijen kunnen ontbranden bij beschadiging, kortsluiting of overladen; laad nooit zonder toezicht.
- Verwijder propellers vóór benchtests, configuratie of firmware-updates.
- Respecteer de spannings- en stroomlimieten in de specificaties; omgekeerde polariteit vernietigt het board.
- Ceci n'est pas un jouet. Interdit aux moins de 14 ans ; mineurs uniquement sous surveillance d'un adulte.
- Composant pour aéronefs sans équipage auto-construits : le constructeur est responsable de l'appareil assemblé et de son utilisation licite.
- Les batteries LiPo peuvent s’enflammer en cas de dommage, de court-circuit ou de surcharge ; ne chargez jamais sans surveillance.
- Retirez les hélices avant les essais au banc, la configuration ou les mises à jour du firmware.
- Respectez les limites de tension et de courant des spécifications ; une inversion de polarité détruit la carte.
