Difference between revisions of "BMP085"
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* [http://www.watterott.com/de/Breakout-Board-mit-dem-BMP085-absoluten-Drucksensor Watterott] | * [http://www.watterott.com/de/Breakout-Board-mit-dem-BMP085-absoluten-Drucksensor Watterott] | ||
| − | == ECMD == | + | == [[ECMD]] == |
| + | {| border=1 | ||
| + | | '''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 [http://en.wikipedia.org/wiki/Barometric_formula 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 | ||
Revision as of 01:59, 12 January 2012
| 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 und 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
