• ATmega328 (with Arduino bootloader)
• RFM69HW 868MHz or 915Mhz module
• MCP1700 3.3v Voltage Regulator
• 28pin DIL IC Socket
• 2x 1uF Ceramic Cap
• Various headers and sockets
• Stripboard

• Solder 28pin DIL IC socket to the strip board
• Cut traces along the centre of the socket
• Check that there is no conductivity between the two halves

• Solder voltage regulator with 1uF capacitor
• Connect voltage output to Vcc as well as ground
• Solder header for Serial (Tx and Rx)

• Program the ATmega328 with the arduino bootloader
• Upload simple script to the micro
• Connect up the usb-serial convertor and test that everything is working

• Solder connecting wires to RFM69HW (GND, NSS, SCK, MISO, MOSI)
• Line up with the ATmega328's corresponding pins. You'll need to bend your connecting wires a bit to fit through the holes in the strip board. Solder these in place.
• The other 2 pins that need to be connected are VCC and DIO0 which are best connected with insulated wire.
  • VCC → 3.3v
  • DIO0 → pin 2 (Interrupt 0)

• Upload repeater script to test RFM69HW
• Check either with Funcube or that it is repeating to other nodes
  • Its been found that some modules are slightly off frequency and so need adjustment to match. The easist way is to use a funcube or RTL dongle and then adjust the frequency to line up with other nodes.

• Solder antenna to ANT and GND pins

• As the current arduino is programmed just to use its internal oscillator it has a special board identification which needs to be added to your IDE. You need to find the boards.txt and add to the end

For Arduino 1.6.1 use this script:

##############################################################

atmega328bb.name=ATmega328 on a breadboard (8 MHz internal clock)

atmega328bb.upload.tool=avrdude
atmega328bb.upload.protocol=stk500
atmega328bb.upload.maximum_size=30720
atmega328bb.upload.speed=57600

atmega328bb.bootloader.tool=avrdude
atmega328bb.bootloader.low_fuses=0xE2
atmega328bb.bootloader.high_fuses=0xDA
atmega328bb.bootloader.extended_fuses=0x07
atmega328bb.bootloader.path=arduino:atmega
atmega328bb.bootloader.file=atmega/ATmegaBOOT_168_atmega328_pro_8MHz.hex
atmega328bb.bootloader.unlock_bits=0x3F
atmega328bb.bootloader.lock_bits=0x0F

atmega328bb.build.mcu=atmega328p
atmega328bb.build.f_cpu=8000000L
atmega328bb.build.core=arduino:arduino
atmega328bb.build.variant=arduino:standard

Otherwise for older versions of Arduino use this:

##############################################################

atmega328bb.name=ATmega328 on a breadboard (8 MHz internal clock)

atmega328bb.upload.protocol=stk500
atmega328bb.upload.maximum_size=30720
atmega328bb.upload.speed=57600

atmega328bb.bootloader.low_fuses=0xE2
atmega328bb.bootloader.high_fuses=0xDA
atmega328bb.bootloader.extended_fuses=0x07
atmega328bb.bootloader.path=arduino:atmega
atmega328bb.bootloader.file=ATmegaBOOT_168_atmega328_pro_8MHz.hex
atmega328bb.bootloader.unlock_bits=0x3F
atmega328bb.bootloader.lock_bits=0x0F

atmega328bb.build.mcu=atmega328p
atmega328bb.build.f_cpu=8000000L
atmega328bb.build.core=arduino:arduino
atmega328bb.build.variant=arduino:standard

• On Mac OS X:

  /Applications/Arduino.app/Contents/Resources/Java/hardware/arduino/

• On Windows :

  hardware/arduino/

• On Linux:

  /usr/share/arduino-1.0.5/hardware/arduino

  though the version number might be different.

• Restart the Arduino IDE and you can now select ATmega328 on breadboard and upload

• Get the latest repeater code from github
• Make sure you update your node ID and location and other settings
• Upload via serial to the board.
• Some additional programming notes with tips for Windows users can be found here: Programming Arduino Nodes using Windows

• Everything appears to run 8x slower
• * Using an ICSP Programmer, 'Burn Bootloader' in the Arduino IDE to set the fuses. This will disable the DIVIDE-BY-8 function.