Yesterday, I found that it was possible to control a servo using a headphone socket with a fairly simple circuit. I've got a project where I need to to control a dc motor via a headphone socket. Is such a thing possible? I basically need it to rotate at various speeds as well as change direction quickly. Apparently it is possible to modify servos to rotate continuously but none of them seem to have the speed I require for my project
Here's some context as to why I need this. Yesterday, I had an idea on how to automate the black card technique in landscape photography where you move a black card up and down in front of the camera during a long exposure. I want to build it on the cheap so this is my design:
The DC motor is stuck to the bolt, which is rotated. The nut is stuck to the plastic cylinder so when the bolt rotates, the cylinder travels up. If you reverse the current, the cylinder travels down. The DC motor therefore needs to work in both directions with the headphone socket circuit. As this is already quite a bulky setup, I'd rather not build a whole arduino into it so if I could get it working via the headphone socket of my phone or music player, that would be ideal!
I've never really done much electronic engineering before so go easy on me please ;)
Any help is much appreciated!