Talk:I2C Compass

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The 5843 is smaller on its own, but has the disadvantage of needing a rather big capacitor in the periphery, which will be as big as the chip itself. The real advantage of the 5843 is that is is 3-axis, meaning that the device will not need to be held horizontal for accurate measurements. Currently I am leaning heavily towards the 5843. initial experiments will have to show how we can pull off stuffing the (in comparison) monstrous capacitor into the space available and still have enough room for wiring and chip plus all the other little gadgets and gizmos that are needed to make the whole contraption work.--[[User:Drdeath|Drdeath]] 00:32, 26 July 2009 (UTC)
 
The 5843 is smaller on its own, but has the disadvantage of needing a rather big capacitor in the periphery, which will be as big as the chip itself. The real advantage of the 5843 is that is is 3-axis, meaning that the device will not need to be held horizontal for accurate measurements. Currently I am leaning heavily towards the 5843. initial experiments will have to show how we can pull off stuffing the (in comparison) monstrous capacitor into the space available and still have enough room for wiring and chip plus all the other little gadgets and gizmos that are needed to make the whole contraption work.--[[User:Drdeath|Drdeath]] 00:32, 26 July 2009 (UTC)
 
== Pricing Update ==
 
== Pricing Update ==
Supply of the HMC5843 is secured, digikey.com has them, and surprise! they are waaay cheaper than expected. Expect cost for the module and diy kit to be on the low end of the initial prediction, or maybe even a bit below!
+
Supply of the HMC5843 is secured, digikey.com has them, and surprise! they are waaay cheaper than expected. Expect cost for the module and diy kit to be on the low end of the initial prediction, or maybe even a bit below!--[[User:Drdeath|Drdeath]] 01:30, 26 July 2009 (UTC)

Revision as of 02:30, 26 July 2009

Contents

Pre-Orders

Pre-orders of anything are non-binding so far and are to evaluate interest by the community. Please sign your name in the appropriate section.

PCB only

DIY-Kit

Ready-made module

Updates

As I proceed through the project, updates on my progress will show up here

Userspace vs kernel module

Initial research in Linux I2C implementation (yes, believe it or not, I dived into this head-first without any prior knowledge of how linux i2c worked) revealed that besides direct kernel-space adressing, I2C devices can also be adressed from userspace via the device file system by means of the i2c-dev module. Since it will apparently be quite easy to actually bake together the contraption once I uncover a source of parts (which I haven't really looked into much so far), be ready to access the module from userspace for the time being, because actually writing a dedicated kernel module for the chip will definitely be the trickier part of the project. --Drdeath 00:14, 26 July 2009 (UTC)

HMC6352 vs HMC5843

The 6352 has the simpler peripheral circuitry, which means less space consumption, but is considerably bigger itself. The 5843 is smaller on its own, but has the disadvantage of needing a rather big capacitor in the periphery, which will be as big as the chip itself. The real advantage of the 5843 is that is is 3-axis, meaning that the device will not need to be held horizontal for accurate measurements. Currently I am leaning heavily towards the 5843. initial experiments will have to show how we can pull off stuffing the (in comparison) monstrous capacitor into the space available and still have enough room for wiring and chip plus all the other little gadgets and gizmos that are needed to make the whole contraption work.--Drdeath 00:32, 26 July 2009 (UTC)

Pricing Update

Supply of the HMC5843 is secured, digikey.com has them, and surprise! they are waaay cheaper than expected. Expect cost for the module and diy kit to be on the low end of the initial prediction, or maybe even a bit below!--Drdeath 01:30, 26 July 2009 (UTC)

Personal tools

Pre-Orders

Pre-orders of anything are non-binding so far and are to evaluate interest by the community. Please sign your name in the appropriate section.

PCB only

DIY-Kit

Ready-made module

Updates

As I proceed through the project, updates on my progress will show up here

Userspace vs kernel module

Initial research in Linux I2C implementation (yes, believe it or not, I dived into this head-first without any prior knowledge of how linux i2c worked) revealed that besides direct kernel-space adressing, I2C devices can also be adressed from userspace via the device file system by means of the i2c-dev module. Since it will apparently be quite easy to actually bake together the contraption once I uncover a source of parts (which I haven't really looked into much so far), be ready to access the module from userspace for the time being, because actually writing a dedicated kernel module for the chip will definitely be the trickier part of the project. --Drdeath 00:14, 26 July 2009 (UTC)

HMC6352 vs HMC5843

The 6352 has the simpler peripheral circuitry, which means less space consumption, but is considerably bigger itself. The 5843 is smaller on its own, but has the disadvantage of needing a rather big capacitor in the periphery, which will be as big as the chip itself. The real advantage of the 5843 is that is is 3-axis, meaning that the device will not need to be held horizontal for accurate measurements. Currently I am leaning heavily towards the 5843. initial experiments will have to show how we can pull off stuffing the (in comparison) monstrous capacitor into the space available and still have enough room for wiring and chip plus all the other little gadgets and gizmos that are needed to make the whole contraption work.--Drdeath 00:32, 26 July 2009 (UTC)

Pricing Update

Supply of the HMC5843 is secured, digikey.com has them, and surprise! they are waaay cheaper than expected. Expect cost for the module and diy kit to be on the low end of the initial prediction, or maybe even a bit below!