The photo shows a CANDONGLE node. It connects the CAN-Bus to a PC (via serial port). The core of the CANDONGLE is the AVR AT90S2313 micro controller provided by Atmel. The AVR is surrounded by the CANBus driver PCA82C250 and an serial driver MAX232. It is powered by 12V dc from the PC.
 

CANDONGLE Schematics

Firmware

The AVR run a nanokernel with two threads:

  1. CANBus thread: it implements the CANBus in software
  2. EventDispatcher: dispatch events* and actions* between the other threads