This 8051 microcontroller-based control circuit adjusts the speed of a small permanent-magnet dc motor via photosensors (see the figure).

Although this circuit connects the DS18S20 1-Wire temperature sensor to a Cypress CY8C26443 PSoC microcontroller, designers can easily adapt it to connect other 1-Wire devices to any microprocessor.

First, the motors may require a voltage that would fry your microcontroller, so you’ll usually need at least a transistor between the micro and the motor-driving transistors.