Relays are something of a necessary evil in the electronics world. While LEDs and other very low power devices can be controlled directly by microcontroller outputs, if you want to switch motors, incandescent lights, and other power hungry items, you’ll need some way to handle current separately.
Mechanical relays do a good job of isolating the switched device from what controls it, but they have a few disadvantages like eventually wearing out. They also make a clicking noise which may or may not be an issue for your application. Solid-state relays, or SSRs, contain no moving parts, and accomplish the same type of power switching with a much longer life cycle and without any noise.
If you’d like to add SSRs your Arduino or Raspberry Pi projects, this 16-channel relay board from Megahome is a great solution. Each relay can handle over 2000W, and the board operates via I2C, meaning you only need two pins to control all 16 outputs. Also, each output is indicated by an LED for easy troubleshooting. Check out the video below to see it switch 16 of what appear to be small incandescent light bulbs on and off, forming a slow and very bright KITT/Cylon display. You might note that there’s no clicking noise, just beautiful glowing lights!
