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howtos:hardware:arm:interfacing_i2c_devices [2019/07/31 01:39 (UTC)] – [Voltage Level Shifting] rramphowtos:hardware:arm:interfacing_i2c_devices [2023/05/28 13:14 (UTC)] – [Preface] louigi600
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 ====== Preface ====== ====== Preface ======
-Most modern PC have several internal components that communicate vital information, like internal temperatures of critical components, over I2C bus. This type of stuff is factory wired into your PC and can be dealt with lm_senosts ... what we want to do here is use an I2C bus on your computer to connect some external I2C sensor like an accelerometer. I'm tagging this in the ARM hardware section because I think that, excluding the lm-sensors stuff, most people will be doing this sort of thing on embedded ARM systems ... but the concepts are applicable to any linux capable system with an I2C bus.+Most modern PC have several internal components that communicate vital information, like internal temperatures of critical components, over I2C bus. This type of stuff is factory wired into your PC and is normally dealt with lm_senosrs ... what we want to do here is use an I2C bus on your computer to connect some external I2C sensor like an accelerometer. I'm tagging this in the ARM hardware section because I think that, excluding the lm-sensors stuff, most people will be doing this sort of thing on embedded ARM systems ... but the concepts are applicable to any linux capable system with an I2C bus. 
 +Should you want to hack one of the many I2C busses on your PC the easiest one to access is the one in the DIMM modules. Modern DIMM modules have an I2C eprom in them that the bios reads to find out the characteristics of the DIMM module. Since the DIMM module can be removed from PC and hacked separately without risking to damage permanently your PC it is probably your safest option. 
  
 ====== Preparing Your Host System ====== ====== Preparing Your Host System ======
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 ===== Detecting Connected Devices ===== ===== Detecting Connected Devices =====
-There are probably many ways to determine what's connected to an I2C bus, I chose to use stuff out of the [[http://www.lm-sensors.org/wiki/I2CTools | i2ctools]] project. I was unable to find a Slackware ARM package for i2ctools so I compiled and installed it on my system.+There are probably many ways to determine what's connected to an I2C bus, I chose to use stuff out of the [[http://www.lm-sensors.org/wiki/I2CTools | i2ctools]] project. I was unable to find a Slackware ARM package for i2ctools so I compiled and installed it on my system. On some distribution the package may be called t2c-tools.
  
 First thing you want to know is what I2C busses are present on your system as there may be more then one and looking in the wrong bus may be frustrating: First thing you want to know is what I2C busses are present on your system as there may be more then one and looking in the wrong bus may be frustrating:

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