AVR-CAN

CAN bus message handler for the ATmega16M1

CAN API

Files: api.h, api.c

The goal of this CAN API is to abstract the inner mechanisms of the CAN bus away from each individual sensor node. Nodes do not have to interact with the registers of the CAN controller, they need only use the available API methods.

Each node implementing this API has access to 2 methods (initCan and sendCANmsg) and must implement 1 method of its own in order to use the API (handleCANmsg). Please see the demo in this project for an example of these methods in use.

Using this API in your project

In order to use this API, you need to implement handleCANmsg, even if you do not intend to send any messages to a given chip. Make sure to include the following in your Makefile: SOURCES += api.c INC += -Isrc/ CFLAGS += $(INC)

Demo Code

Files: client.c, server.c

This is a demonstration of two ATmega16M1s communicating across a CAN bus. The demo uses CAN messages to turn a remote LED on or off based on the state of a momentary button.

The "server" chip sends the state of the button (0x00 or 0xFF) across the CAN bus to the client, which turns an LED on or off in turn.

Making and flashing the demo

To flash code onto an ATmega chip, run the following commands:

• make FILE=client flash for the client
• make FILE=server flash for the server

You may need to append sudo to these commands based on your system setup.