Hi,
We've used the BMP280 sensor for some time and it has worked fine.
We received part delivery of a batch from our manufacturer this week and during verification we found that all 80 of these consistently measures a too low pressure. The offset is 10hPa.
This is very similar to another post (see link below), but in our case VDDIO is tied to VDD. As in that post, we are reading some strange calibration values. I have listed these below.
The software and hardware is the same for the previous 50 that works and these 80 that consistently measures with an offset. The configuration is
- 2x oversampling (temp and pressure)
- Normal measurement mode
- 0.5 ms timeout
- No filter
- Disabled 3-wire SPI
Another thing we have noticied is that the marking on the sensor differ from previous batches we have received. An example from a previous batch was "2DT-KS". On this batch it is "DRL-KL". I'm a little surpised by the last letter.
| Coeff. | Not working | Working |
| T1 | 27785 | 27350 |
| T2 | 26181 | 25922 |
| T3 | 50 | 50 |
| P1 | 37516 | 38823 |
| P2 | -10541 | -10584 |
| P3 | 3024 | 3024 |
| P4 | 7638 | 6850 |
| P5 | -21 | -176 |
| P6 | -7 | -7 |
| P7 | 7241 | 15500 |
| P8 | -5018 | -14600 |
| P9 | -766 | 6000 |
Question 1: What does the "Sub-con ID" on the marking signify and does "L" mean it is not the "new variant"? If so, what does that imply?
Question 2: Any input on these strange coefficients?
