i2c.h

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/**
 * @file i2c.h
 * @ingroup ccs811
 * @author Jason Duffy
 * @date 5th March 2022
 * @brief I2C communications driver for AVR MCU's.
 * @bug No known bugs. 
 * 
 * This file provides basic I2C protocol comms functionality.
 * Please note: Blocking waits are used whilst the host waits for hardware to
 * set flags in registers. 
 */
 
// Functions for i2c communication
#ifndef I_TWO_C_DOT_H
#define I_TWO_C_DOT_H
 
#include <avr/io.h>
 
 
/**
 * Sets pullups and initializes bus speed to desired bus speed.
 */
void init_i2c(uint32_t bus_speed);
 
 
/**
 * Waits until the hardware sets the TWINT flag.
 */
void i2c_wait_for_complete(void);
 
 
/**
 * Sends a start condition (sets TWSTA).
 */
void i2c_start(void);
 
 
/**
 * Sends a stop condition (sets TWSTO).
 */
void i2c_stop(void);
 
 
/**
 * Loads data, sends it out, waiting for completion.
 */
void i2c_send(uint8_t data);
 
 
/**
 * Read in from slave, sending ACK when done (sets TWEA).
 */
uint8_t i2c_read_ack(void);
 
 
/**
 * Read in from slave, sending NOACK when done (no TWEA).
 */
uint8_t i2c_read_no_ack(void);
 
 
#endif // I_TWO_C_DOT_H
 
 
/*** end of file ***/