LDR's to read Positioning Wheel

[TehMaxwell]

Hey all,

I was just wondering if anyone has any experience with using LDR's to read the positioning wheels that can be used to locate sections on a disc. They look like this:

I was thinking of using one to help position a wheel that is spun with a dc motor. Black is 1 and White is 0. This way you can have individual byte arrays for each column of the wheel, so you can say which array you want to go to, and the wheel will spin until it reaches that section. I was thinking of attaching it to a disc that would hold router end mills, so that you could have an automatic dispenser for all of your bits and mills. You could possibly use an arm mechanism to place it into the chuck of your router or rotary tool.

Thanks very much,

Sam

 

[mofy]

LDR's are not the right component for this. They tend to be large area (relatively) and unfocused, no optics. For such a coded disc you would be better off with perhaps optical switches, or a linear detector array with illumination.

 

[Tha fios agaibh]

Why not just use an encoder?

 

[Harald Kapp]

Why not just use an encoder?

The OP is essentially building his own encoder. The image is from the respective Wikipedia page.

LDR's are not the right component for this.

I agree. You'd use photodiodes or photoransistors for this purpose.

 

[TehMaxwell]

Thanks for the tips guys! Ive never used those components before so it would be good to get some experience with new stuff.