I am not all experienced at this sort of thing but never the less I am trying to build a device to dispense labels off a roll. I have a 12v motor that I am using to unroll labels off the roll. The motor runs until a light sensor detects a space between labels and at that point the motor should stop so a label can be removed. The operator would then press a momentary switch button to start the motor again and advance the roll to the next label. The light sensor would then stop the motor again when the next label space is detected. I was thinking of using a locking solenoid that would be activated by the switch and deactivated by the light sensor. I am not sure if that is the right approach and how I would set it all up if it is. Any help would be great!