compass sensor

[bloody-orc]

hi there!

is there any easy way of constructing a reliable compass sensor. i need 5 degree steps to be recognised. as i'm putting on my offroad robot it must tolerate bumps and hills. and also i dont want to put in on a a 1 foot pole over my robot(as some sensors require).

 

[slurp]

have you seen the Hitachi HM755B Compass Modules?

regards,
colin

 

[Oznog]

I've wanted to build a digital compass myself, but cheap and reliable solutions elude me.

There are sensors which only output 8 cardinal directions and can't be calibrated thus basically useless. And there are sensors/modules like the Hitachi HM755B which have useful outputs which are somewhat expensive.

I got a $10 digital compass with LCD display, with a calibration mode, from Harbor Freight Tools. It's got two 2-wire devices about 3/4" long and maybe 0.1" diameter. They're mounted perpendicular, one is perpendicular to the main board and they had to cast the case specifically to accomodate it.

I'm assuming it's a type of inductor, but otherwise I don't get it. If ONLY that stupid module had a serial port output.

 

[williB]

This has nothing to do with the o/p s origional question ..But reading oznogs reply somehow gave me an idea that using a old 3 1/4 " harddrive motor as a Gyro would work great ..
They spin really fast..
They are really small..
all you would need is a little more mass connected to the platten..and some way to measure the distance differential..but the heart of the Gyro is the motor anyway..
:lol: Just thought i would add this ..

 

[bryan1]

Eh Willi,
To add to yours mate I'm hopefully soon to get 100 3x3x3 mm cube neo magnets which I want too use with hall a effect sensor and the idea did occur to me about mounting them in an a array to be a compass. One type of hall effect sensor I did get can sense direction and as hall effect sensors are attracted by the density of flux a stronger magnet at north can act as a centre point so it looks like a good project to tackle :twisted:

Cheers Bryan

 

[bloody-orc]

ˇwell i was really looking for something cheaper than $10. like 5 or so...

 

[slurp]

ˇwell i was really looking for something cheaper than $10. like 5 or so...

just keeps getting tighter that spec....
$5 price, 5 degree accuracy, size constrants and robustness - not much to ask! :wink: