I2C Pressure Sensor
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The BMP085 ([http://www.bosch-sensortec.com/content/language1/downloads/BMP085_DataSheet_Rev.1.0_01July2008.pdf Datasheet]) from [http://www.bosch-sensortec.com/content/language1/html/3477.htm Bosch Sensortec] is a simple, easy to use, pressure sensing device. It speaks I2C and includes a temperature sensor. | The BMP085 ([http://www.bosch-sensortec.com/content/language1/downloads/BMP085_DataSheet_Rev.1.0_01July2008.pdf Datasheet]) from [http://www.bosch-sensortec.com/content/language1/html/3477.htm Bosch Sensortec] is a simple, easy to use, pressure sensing device. It speaks I2C and includes a temperature sensor. | ||
| − | Because of it's tiny size of 5.0mm x 5.0mm x 1.2mm it fits nice into the Freerunner | + | Because of it's tiny size of 5.0mm x 5.0mm x 1.2mm it fits nice into the Freerunner. |
| − | [[Image: | + | [[Image:Bmp085-bottom.jpg]] |
The sensor needs just four wires: power (3.3V, GND) and I2C (SDA, SCL). The wiki page about [[I2C]] describes where to get them. | The sensor needs just four wires: power (3.3V, GND) and I2C (SDA, SCL). The wiki page about [[I2C]] describes where to get them. | ||
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| + | [[Image:Pressure-sensor-bt.jpg]] | ||
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| + | I glued mine next to the BT antenna. | ||
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An experimental kernel driver is available from [http://gitorious.org/freerunner-navigation-board/bmp085 gitorious]. | An experimental kernel driver is available from [http://gitorious.org/freerunner-navigation-board/bmp085 gitorious]. | ||
Revision as of 23:13, 30 September 2009
The BMP085 (Datasheet) from Bosch Sensortec is a simple, easy to use, pressure sensing device. It speaks I2C and includes a temperature sensor. Because of it's tiny size of 5.0mm x 5.0mm x 1.2mm it fits nice into the Freerunner.
The sensor needs just four wires: power (3.3V, GND) and I2C (SDA, SCL). The wiki page about I2C describes where to get them.
I glued mine next to the BT antenna.
An experimental kernel driver is available from gitorious.
It searchs for the chip at I2C address 0x77 and exports a sysfs interface where you can read the temperature and the pressure as well as adjust the internal oversampling.
--Cmair 19:10, 30 September 2009 (UTC)
For other chips and ideas on how to use them see Variometer and Wish_List_-_Hardware_-_Atmospheric.
