Published March 4, 2016 © CC BY-NC

RFM69CW Arduino Shield

Simple RFM69CW shield for Arduino Pro 3.3v with selectable IRQ pin and SMA connector for antenna.

IntermediateWork in progress1 hour1,008

Things used in this project

Hardware components

HopeRF RFM69CW

SparkFun Arduino Stackable Header Kit

OSH Park Custom Shield

SparkFun Reverse Polarized SMA Connector

434mhz Antenna

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

Story

I needed a 434Mhz radio shield for my PWS (SparkFun Weather Shield) and would work with an Arduino Pro 328 - 3.3V, so I made one. The first problem that I needed to overcome was the fact that the Weather Shield is using both of the Arduino Pro's IRQ pins for rain and wind measurements. Luckily for me, the RFM69 library that I am using allows for RF69_IRQ_PIN and RF69_IRQ_NUM to be set to alternative values, 4 and 2 respectively. I used a set of jumpers to select the IRQ pin - the shield can be used with other projects and still have an option of setting the IRQ for the RFM69CW radio.

1 / 2 • Parts before assembly

Code

Overriding default IRQ pin and number

// sample changes for RFM69.h
#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega328P__) || defined(__AVR_ATmega88) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega88__)
  #if defined(IRQ_CONFLICT)
    //  have the sparkfun weather shield
    //  need to have set in main sketch: #define IRQ_CONFLICT
    #define RF69_IRQ_PIN          4
    #define RF69_IRQ_NUM          2
  #elif
    //  default settings
    #define RF69_IRQ_PIN          2
    #define RF69_IRQ_NUM          0
  #endif
#elif defined(__AVR_ATmega644P__) || defined(__AVR_ATmega1284P__)

//
//  The other option is to comment out the whole section in RFM69.h and 
// include in main sketch:
//  #define RF69_IRQ_PIN          4
//  #define RF69_IRQ_NUM          2

//
//  The last, but might not be the most flexible (and the hardest to 
//  troubleshoot 6 months latter), is to redefine the PIN/NUM in the
//  RFM69.h