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

To program these chips, [Aaron] first had to wire up the microcontroller into a circuit. This was just a bit of perf board, a resistor, a few caps, and a USB A plug.

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.