BMP280 problem

Other Hardware Sensors
1

Hi,

wierd problem here with BMP280 pressure, humidity and temp sensor: hooked up to Uno as follows:
BMP280 --- Arduino Uno

Vcc --- +5V
GND --- GND
SCL --- A5 (SCL)
SDA --- A4 (SDA)

First run "I2C scanner" and i got:
"I2C Scanner
Scanning...
IC2 device found as address 0x76 !
done"

So far so good...
But when i load Adafruit BMP280 example "bmp280test.ino" i got this:
"BMP280 test
Could not find a valid BMP280 sensor, check wiring!"

?!?!? Why is that?
I2C scanner can see the device but the BMP280 lib doesn't:/

I tried to use:
bme.begin(0x76) but no luck
Any ideas Folks?

2

wierd problem here with BMP280 pressure, humidity and temp sensor:

I think the weirdest thing here (apart from your spelling of "weird") is your expectation that a BMP280 senses humidity.

3

Do you have pullup resistors on SDA and SCL? If not, try 4.7k resistors.

Pete

4

This is the I2C address definition in the Adafruit_BMP280.h file.

I2C ADDRESS/BITS/SETTINGS
-----------------------------------------------------------------------*/
#define BMP280_ADDRESS (0x77)

Try changing that to #define BMP280_ADDRESS (0x76)

1 Like
5

It's all clear now! The module i bought has markings "BME/BMP280" on it. I though i have BMP280 andtried BMP280 library but it turned out the module is BME280... BME280 lib works as it should:) The address showed by I2C scanner (0x76) is ok so the only change in test sketch is change in address.

Thanks!

6

bogus105:
It's all clear now! The module i bought has markings "BME/BMP280" on it. I though i have BMP280 andtried BMP280 library but it turned out the module is BME280... BME280 lib works as it should:) The address showed by I2C scanner (0x76) is ok so the only change in test sketch is change in address.

Thanks!

BMP280 : Barometric Pressure Sensor - 280; it measures only Temperature and Pressure and from pressure it can compute altitude.

BME280 : Barometric Environmental Sensor - 280; it measures Temperature, Pressure, and Humidity and from pressure it can compute altitude.