BMP280 temperature reading too high (~6°C), BME280 ok. Using different library BMP280 shows correct temperature.

[xtendch]

I have several airrohr setups running. Some of them use a BME280 and some use a BMP280 (currently only one with BME280, 4 with BMP280, more BME280 are ordered). The ones with BMP280 show temperature about 5-6 degrees too high, while the one with BME280 seems to show the correct (lower) temperature.

First I thought my BMP280 modules were bad, but testing the same module with a different BMP280 library outputs correct temperature data. (Library BMX280MI - https://bitbucket.org/christandlg/bmx280mi)

In the airrohr code I see that the code is derived from Adafruits BME/BMP280 library and that both sensors (BME280 and BMP280) are used with takeForcedMeasurement() (and setSampling "MODE_FORCED") to protect against overheating. Somehow that does not seem to work with my BMP280 sensors, but only with the BME280.

Does anyone face the same issues? General issue or only mine? Any ideas what could be fixed in the code?

Sensor Setup:

• Wemos D1 mini (clone) or ESP8266 NodeMCU V3
• PMS7003
• OLED SSD1306 (respectively SSD1315)

[xtendch]

I was also checking #1033 where wifi interference was mentioned (as my cables between EPS8266 and BMP280 are only about 4cm and sensor is close to antenna). But as testing with different library showed correct results I don't think it's the same problem. (To be 100% sure I would I would need to check with some code where wifi transmitting is active at temperature reading time, of course.)

[xtendch]

Update: After ordering more parts I've experimented in using longer cables to connect the BMP280 to the ESP solved the issue. It seems that #1033 is describing this issue already accurately. After that (I've even connected the BMP with the same cable length as before via OLED display (on the I2C) instead of directly to the ESP8266 in parallel to the OLED it worked much better. The distance from the ESP8266 and WiFi shield is still the same, but total cable length from ESP to BMP280 is now about 8-10cm.
(If WiFi is not active at the time of reading BMP280 there is no issue.)