I2C2

A light-weight I2C library written in C.

Installation

$ git clone https://github.com/jack-greenberg/i2c2.git
$ cd i2c2
$ make

Usage

Edit i2c.h to update the SDA and SCL macros to match the pins on your MCU.

#define SDA            PB2
#define SCL            PB3

Then, in your file, you can use the functions.

int main(void) {
    init_I2C(BITRATE_STD); // Initializes timer and interrupts at 100kHz (use BITRATE_FULL for 400kHz)
    start_I2C(0x41, 0x81, WRITE); // Sends start condition and transmits address and register of secondary address
    transmit_I2C('H');
    transmit_I2C('e');
    // ...
    transmit_I2C('d');
    stop_I2C();
    return 0;
}

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

To-Do

• Transmit from primary to secondary
• Implement break when read_ACK_NACK() returns NACK
• Read from secondary on primary
  • Implement repeated start
  • read_I2C()
  • send_ACK()
  • send_NACK()
• Set up clearer guidelines about timers
• Allow for using Timer0 or Timer1
• Add documentation of results from Analog Discovery
• Add more details to Usage
• Make Makefile more flexible

License

MIT