From charlesreid1


This project is an attempt to get two Arduinos (or other microcontrollers) talking to each other via some kind of digital mode (PSK, FSK, OOK, etc.)

The approach:

  • Purchase a breakout board with a wireless antenna (probably 440 MHz or 900 MHz) (x2)
  • Obtain 2 Arduino microcontrollers (Uno, Nano, Leonardo, Esplora) which will communicate using this digital mode
  • Connect the Arduino microcontrollers to the breakout boards, so that they can interface with/utilize the radio breakout board

Use RadioHead:

Step 1: Breakout board

Step 1: purchase a breakout board with a wireless antenna


RFM22B-S2 SMD - 915 MHz -

Communication with the RFM22B is achieved via a standard 4-wire SPI interface. Three configurable general purpose I/Os are also available, the use of which can be tailored towards the needs of your project. A host of other features are also available including an 8-bit ADC, temperature sensor, RX and TX FIFOs, and low-battery detection. See the datasheet below for a complete description of every register and command. The module comes in a 16-pin, 16 x 16mm, SMD package, with pins spaced by 2mm.

Example code:

Hope Electronics info sheet:


RFM69 breakout (915 MHz):

RFM69 breakout (434 MHz):

Plain component (w/o the breakout board) is called the RFM69HCW.

This is the SparkFun RFM69 Breakout, a small piece of tech that breaks out all the pins available on the RFM69HCW module as well as making the transceiver easy to use. his RFM69HCW operates on the 434MHz frequency and is capable of transmitting at up to 100mW and up to 300kbps, but you can change both of those values to fit your application. For example, you can maximize range by increasing the transmit power and reducing the data rate, or you can reduce both for short-range sensor networks that sip battery power. At full power and with simple wire antennas, we can get messages from one side of a large office building to the other through numerous internal walls. In open air you can reach 500 meters or more. With more complex antennas and modulation schemes, similar parts have successfully transmitted from space to the ground (by [ very smart amateur radio enthusiasts]; your mileage may vary)!

The RFM69HCW uses an SPI (Serial Peripheral Interface) to communicate with a host microcontroller, and several good Arduino libraries are available. It supports up to 256 networks of 255 nodes per network, features AES encryption to keep your data private, and transmits data packets up to 66 bytes long.

RFM69HCW hookup guide:

Nooooo idea what this thing is:

  • Apparently, an extra breakout board that takes voltage in from USB, and sends it out?

re sparkfun FTDI beefy 3 breakout:

It can also be used for general serial applications. Built upon the same foundation as our 3.3V SparkFun FTDI Basic Breakout, the Beefy 3 is equipped with an AP2112K voltage regulator making this FTDI basic breakout board capable of handling a current load of up to 600 mA! With the addition of a more “Beefy” voltage regulator your will now be able to power a 3.3V project directly from the FTDI. The pinout of this board matches the FTDI cable to work with official Arduino and cloned 3.3V Arduino boards.


CC1101 wireless transceiver module:

See also


RaspberryPi/Digital Modes