HC-SR04 Ultrasonic Module Distance Sensor 10pcs Proximity Sensor for Arduino with 2cm - 500cm Ranging Distance 5V DC Power Supply

Easy setup & accurate

These ultrasonic transducers are a fantastic deal - I literally had it plugged in and measuring distance within 5 minutes. With some libraries (e. G., NewPing) you can even run the trigger and echo off the same pin. Measurements seem very repeatable, with only a few cm little jitter even at 200cm, and it seemed to support ping at least every 40ms. They do have some side lobes to watch out for though - I was getting some pings off objects up to about 30 degrees off-center. Not usually a problem for clear areas, but may complicate indoor navigation (rather than obstacle avoidance, for which it may simply generate false triggers). I'm a happy hardware hacker, and plan to incorporate several of these into the little rover in working on with my daughter.

My son is working on a 4H project requiring proximity sensors. We ordered this 10-pack of HC-SR04 sensors from EC Buying, and they have been great so far.We've tested every single sensor, and they all work. Their values are all in line with one another which adds to our confidence in their accuracy. We are using these with an Arduino Uno R3.I'm not a fan of how these get shipped (all thrown in a plastic pouch), but it must be fine because they all work!