Simply connect the red wire to the positive supply, and black to negative ground. The display has a microcontroller that will read the voltage, compare it to a stable reference and display the voltage with 0.1V precision on a 3-digit 0.56″ tall 7-segment display. It works from 4.5V up to 30V and is reverse-polarity protected so it will be good for nearly any electronic project! The meter draws 3-4mA to power the microcontroller and display. This particular LED display is a nice vivid green, which we found very readable. To mount to your enclosure, simply cut a 45.5mm × 26.5mm rectangle and snap it in.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.