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);
}
/*
* 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();
}
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);
}
