under construction

APC220 radio

The APC220 radios is one of the simplest ways to implement radio communication between computer devices.

The APC220 provides a simple serial transmit receive interface.

Some specs

  • Voltage: 5V

  • Transmit distance up to 1000m (line of sight) @9600 bps

  • Max TX power 20mW / 13 dBm

  • Frequency is from 418MHz to 455MHz

  • 256 bytes data buffer

  • High sensitivity (-112dbbm @9600 bps)

  • GFSK modulation

  • UART/TTL interface

  • Embedded watch dog

  • Size: 37 x 17 x 6.5 mm (1.46x 0.67x 0.26 in)

   micro TX --> RX(APC220)  ---radiolink---> (APC220)TX -->  RX(another micro)

Forward error encoding handles transmission errors up to a certain level.

Thumb rule says that if you transmit 40 bytes will send up to 80 bytes in air All encoding etc is handled by the radios so the users just see it as a serial wire connection.

Encoding and error correction is handled by the radio so you just have a wireless serial line.


  • TX bufferoverflow - obvious

  • Lost connectivity - not line of sight, distance too long, noise, wealk antennas,…

This apc220 interface and configuration library is based on a simple C class

It is based on use of SoftwareSerial so on a UNO the hardware serial port is available or other things.

On a cansat it could be like

  • hardware serial for logging data on sdcard

    • higher baudrate than for radio to log large amount of data

    • 57600 which gives 5000 bytes to log pr second

  • software serial for telemetri back to your homebase

    • 9600 baud or lower (lower for extending range)

    • a few hundred bytes pr second

Still beware of your databudgets. Dont use all CPU power and time for logging

If you have a MEGA there is 4 hardware serial ports. In that case you can modify library to just use a hardware serial port.

because …

Changing frequency on radio

The library provide a simple interface for reprogram the apc220

See examples

See apc220code.html

Source listnings

list folder: apc220cfg
list folder: apc220serial


Encoding - in general


See links in menu at your left