BME688 strange data

[ole-johan]

Hi. I have used the BME680 and BSEC in a previous design with good results. Now I am working on a new design on a new platform where I am using the BME688. I expect to use BSEC later, but for now I am doing bringup and just need to see that I get decent results from the sensor. So I have implemented the example code for forced mode, and everything runs OK, meaning all the api calls return OK, but I get this strange reading:

bme68x_get_data result: status=80, meas_index=22, res_heat=64, idac=0, gas_wait=128, gas_resistance=795326.88, temp=0.90, pres=190403.41, hum=0.00

To be clear, I only get this type of data, with small variation in the beginning. So it is consistent in giving me wrong data, but there are small changes so I expect I get actual data.

Any tips on what can be wrong? 

[BSTRobin]

Hi ole-johan,

Run example code https://github.com/BoschSensortec/BME68x-Sensor-API/blob/master/examples/forced_mode/forced_mode.c, we don't see any abnormal data. Is your code the same as the example code?

[ole-johan]

Hi, thanks for your prompt reply! 🙂

Yes, this is in fact the example code that I also have implemented. So that is what I found to be strange...

Working with the BME680 for many years, I have never seen any such problems. So I guess this is some stupid, strange bug... 😉

Also, fyi, I have tested this on 3 different units, all with the same issue, so it's not a single unit fault.

Thanks,

Ole-Johan

[BSTRobin]

Hi ole-johan,

The example here can also be used on the BME680. If it is convenient for you, you can run the same example(without any change) and compare it on the BME680.

[rodri16]

I am having same issue with bme688 borad from Adafruit and Heltec Esp32S3 board on Arduino 2.3.2 with esp32 3.0.1

Testing with forced_mode688.ino from Bosch-BME68x-Library after some working time I get wrong values with 80 status value. Readings keep wrong values till mcu is reset.

Debug

14:43:44.395 -> TimeStamp(ms), Temperature(deg C), Pressure(Pa), Humidity(%), Gas resistance(ohm), Status
14:45:24.833 -> 100540, 24.77, 98526.91, 50.67, 41775.46, B0
14:45:26.878 -> 102587, 24.77, 98527.97, 50.66, 42356.05, B0
14:45:28.902 -> 104634, 33.15, 77386.77, 100.00, 6400000.00, 80
14:45:30.943 -> 106681, 33.15, 77386.77, 100.00, 6400000.00, 80