void BaroSensorClass::begin()
{
Wire.begin();
Wire.beginTransmission(BARO_ADDR);
Wire.write(CMD_RESET);
err = _endTransmission();
if(err) return;
uint16_t prom[7];
for(int i = 0; i < 7; i++) {
Wire.beginTransmission(BARO_ADDR);
Wire.write(CMD_PROM_READ(i));
err = _endTransmission(false);
if(err)
return;
int req = Wire.requestFrom(BARO_ADDR, 2);
if(req != 2) {
err = ERR_BAD_READLEN;
return;
}
prom[i] = ((uint16_t)Wire.read()) << 8;
prom[i] |= Wire.read();
}
// TODO verify CRC4 in top 4 bits of prom[0] (follows AN520 but not directly...)
c1 = prom[1];
c2 = prom[2];
c3 = prom[3];
c4 = prom[4];
c5 = prom[5];
c6 = prom[6];
initialised = true;
}
uint32_t BaroSensorClass::takeReading(uint8_t trigger_cmd, BaroOversampleLevel oversample_level)
{
Wire.beginTransmission(BARO_ADDR);
Wire.write(trigger_cmd);
err = _endTransmission();
if(err)
return 0;
uint8_t sampling_delay = pgm_read_byte(SamplingDelayMs + (int)oversample_level);
delay(sampling_delay);
Wire.beginTransmission(BARO_ADDR);
Wire.write(CMD_READ_ADC);
err = _endTransmission(false);
if(err)
return 0;
int req = Wire.requestFrom(BARO_ADDR, 3);
if(req != 3)
req = Wire.requestFrom(BARO_ADDR, 3); // Sometimes first read fails...?
if(req != 3) {
err = ERR_BAD_READLEN;
return 0;
}
uint32_t result = (uint32_t)Wire.read() << 16;
result |= (uint32_t)Wire.read() << 8;
result |= Wire.read();
return result;
}
float Compass::getReading() {
_beginTransmission();
_endTransmission();
//time delays required by HMC6352 upon receipt of the command
//Get Data. Compensate and Calculate New Heading : 6ms
delay(6);
Wire.requestFrom(HMC6352SlaveAddress, 2); //get the two data bytes, MSB and LSB
//"The heading output data will be the value in tenths of degrees
//from zero to 3599 and provided in binary format over the two bytes."
byte MSB = Wire.read();
byte LSB = Wire.read();
float headingSum = (MSB << 8) + LSB; //(MSB / LSB sum)
float headingInt = headingSum / 10;
return headingInt;
}
