BME280 Connection

[bassmint]

I am getting some BME280 Temp/Humidity/Pressure sensors in a few days. Will they work with this easily?

tia

[doxikus]

+1 on this, can you add support for this sensor!?

[fluppie]

Mine will be here in +- 14 days I guess .

[bassmint]

Screen Shot 2015-12-03 at 2.20.35 PM.png (34.3 KiB) Viewed 13488 times

I got mine in yesterday and was hoping it would work under the BMP line.
It is seen but it is unknown.

[fluppie]

One can always compare the libs . https://github.com/adafruit/Adafruit_BME280_Library

[bassmint]

im not that smart.

[fluppie]

Some info I found about the BME280:

https://github.com/RyAndrew/esp8266_i2c_bme280
https://github.com/sparkfun/SparkFun_BM ... no_Library

[costo]

You can test if they work like the BMP085

In the WebServer module look for:

case 0x77:
reply += F("BMP085");

and change it to :

case 0x76:
case 0x77:
reply += F("BMP085");


In the module _P006_BMP085

change this line:
#define BMP085_I2CADDR 0x77
into
#define BMP085_I2CADDR 0x76


then you can test if it works without studying the datasheets
If it doesn't work you just change the things back as they were.

[doxikus]

HI, does someone have this sensor running on espeasy!? If not can we have tih sensor supported in next versions!?

[Martinus]

I've ordered the BME280 from China. Will see what we can do when it arrives...

[Martinus]

BME280 seems to work:

BME280_1.png (6.47 KiB) Viewed 12261 times

Plugin will be available in R67.

[fluppie]

Mine is working but there is something weird with the read-out on the first poll. I use a ESP-201 Dev Board with GPIO2 and GPIO0 as I2C bus.

[fluppie]

And a more trustworthy result on the second poll. But is reads 3 hPa higher then my two BMP085 modules.

[HarpieC]

short question: Is it possible to connect two bme280 with different ids?

I like to measure indoor and outdoor values.

[costo]

Datasheet of BME280 say:

The 7-bit device address is 111011x. The 6 MSB bits are fixed. The last bit is changeable by SDO value and can be changed during operation. Connecting SDO to GND results in slave address 1110110 (0x76); connection it to V DDIO results in slave address 1110111(0x77), which is the same as BMP280’s I²C address.
The SDO pin cannot be left floating; if left floating, the I²C address will be undefined.

usually the SDO_pin is connected to ground so default address is 0x76. In the ESPEasy code I2C address 0x77 is reserved for for BMP085.

If you want to connect a second BME280 you have to change the I2C address to 0x77 by making the level on SDO_pin HIGH.
On some boards there is a solder pad, carefully cut the connection between the two solderpads with a sharp knife and solder the opposite pad to the centerpad. On other boards SDO pin is a outside boardconnection, so connect that pin to Vcc

Also in the source of ESPEasy you have to change the WebServer.ino file so that ESPEasy recognizes the second BME280.

Find this part:

Code: Select all

        case 0x76:
          reply += F("BME280");
          break;
        case 0x77:
          reply += F("BMP085");
          break;

change that to:

Code: Select all

        case 0x76:
        case 0x77:
          reply += F("BME280");
          break;
 //       case 0x77:
 //         reply += F("BMP085");
 //         break;

As a result of this change in code the BMP085 will not be recognised anymore.

[Drum]

3hPa is well within the accuracy listed in the datasheets.