Other Parts Discussed in Thread: CC2640
Hello, we have the following issue when doing a measurement using HDC2010. The sequence is as follows:
1) Power on the sensor, wait 4.5 ms. (the datasheet says the sensor should be ready in at most 3 ms) The supply stabilizes at 2.95V immediately (like, within 0.1ms) and seems very clean when sampled on the scope.
2) Issue a MEAS_TRIG command.
3) Poll the DRDY_STATUS bit to see if the measurement is complete. ( The polling takes around 1ms each time, and usually the sensor reports data ready on the second time we poll it. )
4) When DRDY_STATUS==1, read out temperature and humidity.
5) Power down the sensor.
What we occasionally see is captured above:
After powering up and starting the measurement, the sensor reports status 0x90 (DRDY_STATUS==1 | HHSTATUS==1) the first time we read out register 0x04. When we proceed to read out the temperature and humidity data, the temperature is typically a few degrees higher compared to earlier (successful) measurements, and the humidity value is always saturated to 0xFFFE.
Any insight you may have as to what causes this critical issue, and what can be done to remove it, is highly appreciated.