/*
* Transmit byte array to slave (addr)
*
* @param addr Address of the slave
* @param size Number of bytes in data to transmit
* @param data Array of bytes
* @param delay_us Microseconds to delay between each send
*/
void i2c_tx(uint8_t addr, int size, uint8_t *data, int delay_us) {
i2c_acquire_bus(); // Waits for bus to become idle
i2c_tx_addr(addr, I2C_WRITE, delay_us); // Transmit start bit, slave address, and write bit
// Send each byte in data
for(int i = 0; i < size; i++)
i2c_tx_byte(data[i], delay_us);
// Terminate communication with slave
i2c_rxtx_end();
}
int hashlet_setup(const char *bus, unsigned int addr)
{
int fd = i2c_setup(bus);
i2c_acquire_bus(fd, addr);
wakeup(fd);
return fd;
}
/*
* Reads count bytes of data from the slave (addr)
* @param addr Address of the slave to read from
* @param size Number of bytes to read from the slave
* @param data Array of bytes to transmit
* @param delay_us Busy waits for delay_us microseconds following each transferred byte
*/
void i2c_rx(uint8_t addr, int size, uint8_t *data, int delay_us) {
i2c_acquire_bus(); // Wait for bus to become idle
i2c_tx_addr(addr, I2C_READ, delay_us); // Send start bit, slave address, and read bit
MCF_I2C0_I2CR &= ~(MCF_I2C_I2CR_MTX); // Become a receiver
MCF_I2C0_I2CR &= ~(MCF_I2C_I2CR_TXAK); // Configure to ACK each recv'd data byte
// Read a dummy byte in order to complete the mode switch
uint8_t dummy = i2c_rx_byte(delay_us);
// Master-receivers must generate clock pulses on SCL to recv 8 data bytes from slave
// Read and ACK up until the last byte (size-2)
for(int i = 0; i <= (size-2); i++)
data[i] = i2c_rx_byte(delay_us);
// NACK to stop transmission and read the last byte
MCF_I2C0_I2CR |= MCF_I2C_I2CR_TXAK;
data[size-1] = i2c_rx_byte(delay_us);
// Terminate communication
i2c_rxtx_end();
}
