This library provides interrupt-based I2C slave functionality for Atmel 8-bit microcontrollers equipped with a TWI peripheral.

It is somewhat based on an existing library found here: https://github.com/devthrash/I2C-slave-lib

• I2CSlave.c -- Implements init/stop, and interrupt-based receive and request logic
• I2CSlave.h -- Function prototypes and a convience method for transmitting data

Provide callbacks for receiving and handling requests in your application code. eg:

void I2C_received(uint8_t data);
void I2C_requested();

I2C_setCallbacks(I2C_received, I2C_requested);

The library calls the received callback for each byte the master transmits to the slave. The library calls the requested callback for each byte the master attempts to read from the slave.

Init the I2C slave with the slave address

I2C_init(I2C_ADDRESS);

Transmitting data to the master when requested

I2C_transmitByte(data);

The example in main.c implements a sample application in which the slave can receive a byte, and then will echo the byte when requested.

To compile: make