/challenges-projects/design-challenges/hats-off/b/blog/posts/sherlock-holmes-case-hat---2-debugging-values-on-the-gemma-using-an-ledToday, I was going to do a video and post on how to use the HCSR04 Ultransonic Rangefinder, but I may have accidentally set it down on some energized wires and fried it. That's alright though, I have a box of them over at my local hackerspace, Makersen-USTelligent Community 12