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OpenLRS is a radio control system designed by Flytron in Turkey. For most of us, the name will make clear that this is an open source product. Source code is available for download, you can make improvements or change the code and share these with others.

The OpenLRS M1 is an open source transmitter module that is configurable for any channel (420-450mhz) or any protocol or extra features as telemetry receiver of OpenLRS Rx module. The M1 module exists of a 100mW RFM22B RF unit and Atmega328 processor with Arduino Bootloader.

The TX module includes:

• Frequency Hopping on 3 channels (see below)
• Serial port for firmware upload and telemetry application
• a buzzer for audible information
• bi color led for visible information
• RFM22B tranceiver module including Si4432 chip with configurable 0-100mW output, Frequency hopping capability and hundreds of other features
• 16Mhz Atmega328 processor with Arduino Pro Mini compatible bootloader.

Frequency Hopping
The code that is preloaded to the transmitter does 3 channel frequency hopping (not FHSS, FH only) for reducing risks. The standard refresh rate is the same as your normal transmitter (50hz), if one of channels is disabled by an external source, refresh rate is reduced to %66 (33hz) , if you loose 2 of 3 channels you can still fly with only %33 (15hz) refresh rate. If you don't like how Flytron has implemented frequency hopping, you can write your own hopping codes or just use 1 solid channel.

The receiver (is also a transmitter)
If you don't need the Futaba Tx module's advantages, you dont need an M1 modules too. Just order 2 receivers and update the one of them as a transmitter. Because M1 module and Rx modules using same RF modules (RFM22B) . Only you should change the pinouts of transmitter code. Code will be shared on the Flytron website shortly.

The RX module includes:

• Serial Port for firmware upload and telemetry application
• 3.3v I2C port for all modern sensors as WiiMotionPlus, WiiNunchuk, MEMs gyros, accelerometers, barometers, etc.
• 8 channel servo output
• PWM output for RSSI output. (You can modify it to be a 9th channel)
• Red and green LEDs for visible informations
• RFM22B tranceiver module including Si4432 chip with configurable 0-100mW output, Frequency hopping capability and hundreds features.
• 16Mhz Atmega328 processor with Arduino Pro Mini compatible bootloader.

Telemetry
The OpenLRS Rx module is actually a Transceiver, that means that you can use it as a transmitter or a telemetry transmitter. Just imagine, you can follow your plane's voltage levels or sensors of your quadrocopter and you can change the configuration by your PC.

Serial or Parallel PPM selectable
If you are using an autopilot/multicopter controller with serial PPM. You dont need any firmware change. Just plug a jumper (binding plugs of 2.4ghz receivers) between channel 1 and 3's signal outputs. OpenLRS Rx detects the jumper when startup and gives 2 short blink. This mean it's giving serial PPM signal from 8th channel.

 
You dont need external multicopter controllers or autopilots
The OpenLRS Rx module, includes serial and I2C ports for your future projects. Just include a WiiMotionPlus (DealExtreme) and upload your code for making a basic quadrocopter. Add a Wii Nunchuck and you have 6DOF IMU. or just buy a 9DOF IMU and connect. Our 3.3v I2C port compatible with all of modern I2C sensors. You can connect your GPS or other Serial equipments with serial port.

7 Watt booster for UHF frequencies
The booster is using a Mitsubishi RA07M4047M RF amplifier to generate a deadly 7W RF power, extending the range of your Long Range System (LRS) massively. The output power is configurable by the voltage you supply to it. It starts boosting from 3.7v(0.8W) to 9v(14W).  You can supply power to this booster with a 2S lipo (7.2-8.4v) battery and it will give you 7-10W power, depending on battery voltage. This booster can be used with any (if not all) of the known LRS's (DragonLabs, Thomas Scherrer TLRS, EzUHF)

Flytron

Flytron has all information on above products listed on their website. Schematics for both the transmitter and receiver are available as pdf on the specific product pages. There you will also find datasheets for the transceiver chips/modules used. Flytron also has a forum section where their Long Range System items can be discussed Last, but not least the source code used with OpenLRS is available for download.