void i2c_lpc_transfer(i2c_bus_t* const bus,
const uint_fast8_t slave_address,
const uint8_t* const data_tx, const size_t count_tx,
uint8_t* const data_rx, const size_t count_rx
) {
const uint32_t port = (uint32_t)bus->obj;
size_t i;
bool ack = false;
if (data_tx && (count_tx > 0)) {
i2c_tx_start(port);
i2c_tx_byte(port, (slave_address << 1) | I2C_WRITE);
for(i=0; i<count_tx; i++) {
i2c_tx_byte(port, data_tx[i]);
}
}
if (data_rx && (count_rx > 0)) {
i2c_tx_start(port);
i2c_tx_byte(port, (slave_address << 1) | I2C_READ);
for(i=0; i<count_rx; i++) {
/* ACK each byte except the last */
ack = (i!=count_rx-1);
data_rx[i] = i2c_rx_byte(port, ack);
}
}
i2c_stop(port);
}
/*
* Starts a transmission with the slave by putting the board into master-transmitter mode,
* sending the slave address and read/write bit.
* The I2C bus should be idle (i2c_acquire_bus()) before calling this function
*
* @param addr Address of slave
* @param rw 0x01 for read, 0x00 for write
* @param delay_us Microseconds to delay between each send
*/
void i2c_tx_addr(uint8_t addr, uint8_t rw, int delay_us) {
MCF_I2C0_I2CR |= MCF_I2C_I2CR_MTX; // Make board a transmitter
MCF_I2C0_I2CR |= MCF_I2C_I2CR_MSTA; // Make board a master (which sends the start bit)
// Compound first 7 address bits followed by the rw bit, then send
uint8_t hello = 0;
hello |= addr << 1;
hello |= rw << 0;
i2c_tx_byte(hello, delay_us);
}
/*
* 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();
}
void i2c_lpc_transfer(const uint32_t port,
const uint_fast8_t slave_address,
const uint8_t* const data_tx, const size_t count_tx,
uint8_t* const data_rx, const size_t count_rx
) {
i2c_tx_start(port);
i2c_tx_byte(port, (slave_address << 1) | I2C_WRITE);
for(size_t i=0; i<count_tx; i++) {
i2c_tx_byte(port, data_tx[i]);
}
if( data_rx ) {
i2c_tx_start(port);
i2c_tx_byte(port, (slave_address << 1) | I2C_READ);
for(size_t i=0; i<count_rx; i++) {
data_rx[i] = i2c_rx_byte(port);
}
}
i2c_stop(port);
}
