BMP085
| BMP085 | |
|---|---|
| Status | Experimental
|
| menuconfig | I/O->I2C Master Support->BMP085 |
| Pinning | no |
| Ecmd | yes |
| Control6 | no |
| Depends on | ECMD, I2C Master |
| Requires | - |
| Code | https://github.com/ethersex/ethersex/blob/master/hardware/i2c/master/i2c_bmp085.c |
Contents
Bosch BMP085 and BMP180 barometric pressure sensors
Sensors
- Cheap (about 6 EUR)
- Small
- Precise (Resolution 0.25m, absolute accuracy +-2.5 hPa)
- Digital readout via I2C
- BMP085 and BMP180 are code-compatible, the BMP180 comes in a smaller package
Availibility
Pure sensors
Breakout boards
ECMD
| Command Syntax | Short description |
| bmp085 temp | Returns the temperature in 0.1°C (16 Bit integer) |
| bmp085 apress | Returns the absolute pressure in Pa (32 Bit integer) |
| bmp085 height <p0> | Returns the height in cm. Needs the pressure p0 at NN as parameter (given in Pa, 32 Bit integer). |
| bmp085 pressnn <height> | Returns the pressure p0 at NN in Pa. Needs the current height in cm (32 Bit integer). |
Pressure calculations
- Pressure calculations for the height and pressnn commands are done using the Barometric formula
Precision
- The sensor is sensitive to air turbulences (propellers, fans, loud music)
- The sensor is sensitive to power supply ripple - if not using a battery try to filter it well
- The results will have some noise, filter them with a moving average or other algorithm to get good results
