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Topic: BME280 Problem (Read 5939 times) previous topic - next topic

ian1945

Hello to all,
I have bought some cheap BME280 pressure,temperature & humidity breakout boards from China.
They are labelled 'GY-BME/P280 and were described as 'BME280' modules.
But they are not, they are BMP280 modules which do not have the humidity output.
There are a number of these modules on Ebay with different shapes and sizes and I have seen references in forums by people who have used them and which DO have the humidity output.

My question is, can anyone point me at a reasonably priced module which will give me a humidity output.
Thank you.


756E6C

#1
Apr 14, 2017, 06:15 am Last Edit: Apr 14, 2017, 06:20 am by 756E6C
This works great for me, but "reasonable" is relative.
https://www.adafruit.com/product/2652
Adafruit has several cheaper lower cost models.

downloaders

I have been searching for an answer to why my "BME280" does not output humidity for some hours now.

Seems ian1945's explanation is the correct one, they are fakes, and actually BMP280.

I've been searching for a way to identify the real BME280 sensors. And it looks like the sensor itself has to visually be more like a square than like a rectangle.

So it has not to look like this:



But more like this:


This specific last one, reads humidity as per this post: http://forum.arduino.cc/index.php?topic=379563.0

So this should be the answer, looking for this exact sensor, or for one where the actual sensor is square.

ian1945 : Which library have you used for the one you have?

downloaders

In the meantime I have found this bosh page, confirming what i said above about the shape.
https://www.bosch-sensortec.com/bst/products/all_products/bme280

aaanekre

In the meantime I have found this bosh page, confirming what i said above about the shape.
https://www.bosch-sensortec.com/bst/products/all_products/bme280
This entirely incorrect. in fact it is opposite. Have a look on the Bosch datasheet page 41 here:  http://www.mouser.com/ds/2/783/BST-BMP280-DS001-18-1111099.pdf

03Z KP is a Bosch number while 031 UP is not.

Also we can see that the Bosch chip is not square either, but 2.0x2.5mm

photoncatcher

I have exactly the same BMP280 clone as you show in your picture, first post. Same experience as you have: no humidity, only pressure and temperature. I solved the problem by mounting a Si7021 next to the BMP280.

Aliexpress https://nl.aliexpress.com/item/Industrial-High-Precision-Si7021-Humidity-Sensor-with-I2C-Interface-for-Arduino/32453176349.html?spm=a2g0z.search0104.3.61.trvzUx&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_5700015_10151_10344_10068_10345_10342_10343_10340_10341_5760015_10541_10084_10083_10304_10307_10301_10177_5640015_10060_10155_10154_10056_10055_5750015_10539_10538_5370015_10537_10312_10536_10059_10313_10314_10534_10533_100031_10103_10073_10102_10142_10107,searchweb201603_30,ppcSwitch_5&btsid=6d8e0347-7d7d-4f3c-9069-46f4ac67d4e9&algo_expid=5b53888b-4e9e-430a-9987-dd5bfe1146ac-8&algo_pvid=5b53888b-4e9e-430a-9987-dd5bfe1146ac

very cheap: 2 euros

wvmarle

At 2 Euro you can't be getting a BME280 as in wholesale they cost more than that (iirc about USD 4 in volume, vs less than USD 1 for the BMP280).
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

photoncatcher

mmmm... my precious Aliexpress 'BMP280' might be as well a clone 'made in China'

wvmarle

If you ordered the BMP280 you can be quite sure you will actually get the BMP280 (temp & pressure) and not it's sibling, the BME280 (temp, pressure & humidity) :-)
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

bitbank

#9
May 20, 2019, 01:08 pm Last Edit: May 20, 2019, 01:10 pm by bitbank
I got a bunch of the same board as shown above for $2.45 each from China and they work fine. I can't verify that they're not clone chips, but they do report T + H + P correctly.

Library? We don't need no stinkin' library...we write our own

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