Tracker ONE (ONE523M) with M8 Sensor Temperature/Humidity

johngoode · January 13, 2024, 12:33pm

I have followed the M8 temperature/humidity tutorial. And now I'm getting temp & humid readings:

"sh31_temp": 35.6306
"sh31_humid": 26.1173

The problem I have is that the temperature is reading about double what it should be and humidity is less than half what I think it should be.

Ideas/solutions/observations would be very welcome.

rickkas7 · January 16, 2024, 10:48am

It's not clear why that's happening. If there was a data communication error the CRC check would fail. It's possible that the formula in the library is incorrect, but it seems to have worked properly in the past and hasn't been touched in 4 years.

github.com

particle-iot/sht3x-i2c/blob/main/src/sht3x-i2c.cpp#L217


      
          int Sht3xi2c::pr_get_reading(double *temp, double *humid)
          {
              _wire->requestFrom(_i2c_addr, 6);
              if (_wire->available() != 6)
              {
                  return SHT31_I2C_ERROR;
              }
              uint8_t ts[2], rh[2];
              ts[0] = _wire->read();
              ts[1] = _wire->read();
              *temp = -45.0+(double)(175.0*((uint16_t)((ts[0]<<8)|ts[1]))/0xFFFF);
              if (_wire->read() != crc8(ts, 2))
              {
                  return SHT31_CRC_ERROR;
              }
              rh[0] = _wire->read();
              rh[1] = _wire->read();
              *humid = 100.0*(double)(uint16_t)((rh[0]<<8)|rh[1])/(double)0xFFFF;
              if (_wire->read() != crc8(rh, 2))
              {
                  return SHT31_CRC_ERROR;

johngoode · January 19, 2024, 5:37pm

It makes me feel like I'm the only one to buy and try the M8 sensor.

system · July 20, 2024, 5:38am

This topic was automatically closed 182 days after the last reply. New replies are no longer allowed.

Topic		Replies	Views
I2C unstable data readings Hardware	6	3362	November 6, 2016
Monitor One - Can I connect SHT-31 from Tracker One? Hardware tracker , monitor-one	3	150	July 20, 2024
E SERIES EVAL KIT TUTORIALS - Temp Sensor Readings Hardware electron	4	460	November 11, 2021
DS18B20 is throwing -127C from time to time Getting Started	6	5415	October 11, 2015
Temperature monitor issue Troubleshooting	2	691	April 29, 2019

Tracker ONE (ONE523M) with M8 Sensor Temperature/Humidity

Related topics