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
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.
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?
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Interesting. If I read the datasheet I thought that KM would be acceptable; "(L = "S", "M" for new variant, both part number 0273300436)".
Some are bought by our EMS, some where bought from win-source.net. (Well aware its not an authorized distributor) It has been difficult to procure the component, so we have at times been forced to buy from spot markets and other alternative sources.
I appreciate your responses.
Sorry for my mistake.
According to the new version BMP280 datasheet at https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bmp280-ds001.pdf, it is true that BMP280 with marking "009 KM" is the right part because "(L = "S", "M" for new variant, both part number 0273300436)". I was reading the old version of BMP280 datasheet as shown in the attached file.
Therefore, both "009 KM" and "2UG KS" markings are right BMP280 parts. Sorry about that.