[TAG] Working with External Sensors

[Peter Hüwe]

Am Montag 12 Juli 2010 18:48:36 schrieb Deividson Okopnik:
> Hello TAG!
> 
> Im doing some research in here, and was wondering if any of you ever
> worked with external sensors.
> 
> What i had in mind was having temp/humidity sensors plugged into my
> computer and reading theyr values on linux to use on some program ill
> write.
> 
> If anyone ever did this, what kind of hardware did you use?


Hi,

there are several ways to access your sensors.


- attach the sensors to the buses on your mainboard and then use 
lm_sensors/i2c_tools to read them out.

This works quite well if you have access to these busses like i2c/spi - but 
unfortunately it isn't that easy (unless you're good with the soldering iron) 
to attach your components to the busses - if you're unexperienced with this, 
it is quite dangerous.
On embedded platforms (like the atmel ngw100) you have accessible io pins that 
you can use - there it is really easy.

However since your monitor uses I2C to annouce its EDID/DDC capabilities you 
can use you vga cable to hook up components -- however this might damage your 
hardware too;)
http://www.lammertbies.nl/comm/cable/VGA-monitor.html -- PIN12 Pin 15
http://www.paintyourdragon.com/?p=43


- use an arduino / bus-pirate

The other, perhaps more sensible method would be to use a arduino or bus-
pirate. There you can access the busses and sensors quite easily, you only 
have to write the software for it.
Arduinos are quite useful and easy to use, so they are quite popular among 
design and multimedia students.
There a plenty of arduino clones, ranging from 20 bucks to over 100.
http://en.wikipedia.org/wiki/Arduino

Bus pirate is quite useful if you just want to try a sensor out and see how it 
works.
http://dangerousprototypes.com/bus-pirate-manual/

- build your own board using a microcontroller
same as arduino, just the hard way ;) on the other hand it might be more 
comfortable/cheaper.

- buy some expensive hardware ;)
Maybe there are even SPI/I2C/IWire expander cards.


If you have any further questions, don't be afraid to ask.


Regards,
Peter