Many products use solenoids to open and close valves. A microcontroller can control solenoids programmatically using a GPIO pin and a simple circuit.
Using LEDs in Embedded Designs
LEDs are a common element of many embedded designs. Though the devices are simple; their implementation is not always simplistic. Optimizing LED cost and performance includes ensuring the driving circuitry is providing the correct voltage and current.
Motor Control using PWM and PID
Bi-directional motor control can be done using an H-bridge circuit with pulse-width modulation (PWM) from a microcontroller to vary the speed. Several design challenges include preventing shoot-through, implementing a snubber circuit, as well as open and closed loop (such as PID) control mechanisms.