Another answer to the "what to do with my old hard drive" question

[IronJungle]

How about.... Use it as a PICAXE input device. My simple proof of concept with code, etc here:
http://ijprojects.blogspot.com/2012/07/repurpose-old-disk-drive-as.html

Long term, would the PICAXE complain about seeing a negative 500mV on the ADC input?

 

[boriz]

"Long term, would the PICAXE complain about seeing a negative 500mV on the ADC input? "

Possibly. But consult the datasheets for accurate information.

Can you provide connection information or better still, a circuit diagram.?

 

[IronJungle]

boriz:

The build document page is complete with 'scope trace, code, etc. See: http://ijprojects.blogspot.com/2012/07/repurpose-old-disk-drive-as.html

The quickie answer to your question is that the disk drive stepper motor is connected straight into the PICAXE ADC. It would make for a pretty boring circuit diagram. I just pieced this together because I thought it was an interesting concept.

 

[boriz]

Interesting. Agreed.

"the disk drive stepper motor is connected straight into the PICAXE ADC"

Thanks. That explains everything.

 

[nick12ab]

I thought it was a three-phase motor, not a stepper.

Anyway, what would happen if you directly connected a motorized tool to that hard drive to make it spin faster? Would that make it more than 500mV?

 

[SAborn]

Yes they are a 3 phase motor and hence will produce AC from the coils.
These have been used as rotory encoders etc with picaxe before and a google search should find several circuits.

Here is a few things you can do with a HDD motor or the disc.


http://www.youtube.com/watch?v=ksUP6XmmKs4

http://www.youtube.com/watch?v=HS8Yjcs3j-s&feature=related


http://www.youtube.com/watch?v=bVoPrvjvSKs&feature=related

 

[IronJungle]

@nick12ab: Have 'scope. Have motorized tool. Experiment is on the list.