Emil's Projects & Reviews

OpenHardware & OpenSource

Entries tagged "hc-sr04".

Making a better HC-SR04 Echo Locator 22nd January 2014

I have bought several cheap echo location circuits from AliExpress and I'm planning to use them in one of my robotics projects.

HC-SR04 Front ViewHC-SR04 Back View

They are very cheap especially if you buy a dozen you can get them bellow 2$ shipped. Once they've arrived, to test them, I wrote a quick C test program for an AVR board which displays the distance in cm to an obstacle. The results were pretty accurate for as far as 3-4m distance for hard obstacles. Unfortunately when there are no obstacles in front of this detector or when the obstacles don't have hard surfaces then erroneous results are returned.

I wanted to understand why this was happening so the first step was to reverse the HC-SR04 module schematic.

This entry has been cut, click to read on.

207 comments. Tags: avr, hc-sr04, ultrasound.

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