/*
* Function: getLastTemp()
* --------------------
* Used to retrieve last temperature measurement, idea is to save some time on
* conversion-> because SI7020 does relative humidity(RH) measurement it also measures
* temperature.
*/
void getLastTemp() {
i2c_start();
send_i2c_byte(SI7020ADR_W); // address +0 write
send_i2c_byte(READ_LAST_TEMP_CMD);
i2c_repeatedStart();
//i2c_start();
send_i2c_byte(SI7020ADR_R); //adresss +1 read
i2c_mIdleI2C1();
ttLSB = i2c_read_ack();
i2c_ack();
i2c_mIdleI2C1();
i2c_ack();
ttMSB = i2c_read_ack();
i2c_mIdleI2C1(); /////////////////////// maybe?
i2c_nack();
i2c_stop();
temperatureCode.b[0] = ttLSB;
temperatureCode.b[1] = ttMSB;
}
void read_i2c(uint32_t i2c, uint8_t i2c_addr, uint8_t reg, uint8_t size,
uint8_t *data)
{
int wait;
int i;
while (i2c_busy(i2c) == 1);
while (i2c_is_start(i2c) == 1);
/*Setting transfer properties*/
i2c_set_bytes_to_transfer(i2c, 1);
i2c_set_7bit_address(i2c, i2c_addr);
i2c_set_write_transfer_dir(i2c);
i2c_disable_autoend(i2c);
/*start transfer*/
i2c_send_start(i2c);
wait = true;
while (wait) {
if (i2c_transmit_int_status(i2c)) {
wait = false;
}
while (i2c_nack(i2c)); /* Some error */
}
i2c_send_data(i2c, reg);
while (i2c_is_start(i2c) == 1);
/*Setting transfer properties*/
i2c_set_bytes_to_transfer(i2c, size);
i2c_set_7bit_address(i2c, i2c_addr);
i2c_set_read_transfer_dir(i2c);
i2c_enable_autoend(i2c);
/*start transfer*/
i2c_send_start(i2c);
for (i = 0; i < size; i++) {
while (i2c_received_data(i2c) == 0);
data[i] = i2c_get_data(i2c);
}
}
static void i2c_state_update(i2c_interface *i2c, int data, int clock)
{
if (!i2c)
return;
switch (i2c->state) {
case STOPPED:
if (data == 0 && i2c->last_data == 1 && clock == 1)
i2c->state = INITIALIZING;
break;
case INITIALIZING:
if (clock == 0 && i2c->last_clock == 1 && data == 0)
i2c->state = SENDING_BIT7;
else
i2c_enter_stop(i2c);
break;
case SENDING_BIT7 ... SENDING_BIT0:
if (clock == 0 && i2c->last_clock == 1) {
i2c->buffer = (i2c->buffer << 1) | data;
i2c->state++; /* will end up in WAITING_FOR_ACK */
} else if (data == 1 && i2c->last_data == 0 && clock == 1)
i2c_enter_stop(i2c);
break;
case WAITING_FOR_ACK:
if (clock == 0 && i2c->last_clock == 1) {
if (i2c->current_addr < 0) {
i2c->current_addr = i2c->buffer;
i2c_start_transfer(i2c->bus, i2c->current_addr & 0xfe,
i2c->buffer & 1);
} else
i2c_send(i2c->bus, i2c->buffer);
if (i2c->current_addr & 1) {
i2c->state = RECEIVING_BIT7;
i2c->buffer = i2c_recv(i2c->bus);
} else
i2c->state = SENDING_BIT7;
} else if (data == 1 && i2c->last_data == 0 && clock == 1)
i2c_enter_stop(i2c);
break;
case RECEIVING_BIT7 ... RECEIVING_BIT0:
if (clock == 0 && i2c->last_clock == 1) {
i2c->state++; /* will end up in SENDING_ACK */
i2c->buffer <<= 1;
} else if (data == 1 && i2c->last_data == 0 && clock == 1)
i2c_enter_stop(i2c);
break;
case SENDING_ACK:
if (clock == 0 && i2c->last_clock == 1) {
i2c->state = RECEIVING_BIT7;
if (data == 0)
i2c->buffer = i2c_recv(i2c->bus);
else
i2c_nack(i2c->bus);
} else if (data == 1 && i2c->last_data == 0 && clock == 1)
i2c_enter_stop(i2c);
break;
}
i2c->last_data = data;
i2c->last_clock = clock;
}
