Let's Make Robots!

Homemade digital compass

Some time ago OddBot posted this circuit for a homemade digital compass based on hall effect sensors:

Compass_Schematic.jpg

Unfortunately CircuitBurn couldn't make it work. However I'm inclined to try again. A cheap DIY compass would be great.

So if anyone has ANY idea as to how this could be achieved let's hear it. It could be an improvement on OddBot's circuits or something completely different and wacky :D

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Gareth's picture

paint a rainbow colour around the compass (flat or globe type) and use a colour detector for output.

..... or just a plain grey scale and measure reflected light (globe lightproofed)

Aniss1001's picture

Supposedly cheap IR sensors like the QRB1134 and QRD1114 can also be used to detect greyscales. Not sure about how precise it would be though. I'll make some experiments with that later today since I've allready got some QRB1134 hooked up for testing (I've been working on a wheel encoder which I finally got to work properly).

Anyway keep 'em comin' :D

Gareth's picture

My first thought is to use this as a starting point - this one has even dotted red markers.

These types are sensitive to movement and would need to be filled with light oil and would have to be level for measurement.

Not sure how a "Hall  Effect sensor" would detect (any metal near would have to be non magnetic !!)

Maybe IR with encoder pattern on globe.. (maybe placed inside a hacked mouse)

compass.jpg

 

Aniss1001's picture
Perhaps if you placed hall effect sensors around it they could detect the magnet?
Gareth's picture
As soon as i find my globe compass i will experiment.
Aniss1001's picture
Painting an encoder pattern and using IR sensors sounds pretty creative too :D Keep up the good work...
Aniss1001's picture
...you may wanna place on a stick somehow to keep it away from the motors and other things that may be magnetic?
TeleFox's picture
A tiny Faraday cage would block a lot of external influences, while still allowing earth's magnetic field inside.