Let's Make Robots!
Most students and hobbyist will use servos at some stage when building a robot. This tutorial uses Arduino sample code but the concepts are the same with any micro … Read more

Problem with HC-SR04 distance sensors

Hi Everyone,

I have been finding that I get erratic distance measurements on my tests with the HC-SR04 sensors. I put together a circuit with 128x64 OLED SSD1306 I2C display (Really like that module, by the way) connected on a breadboard to Arduino Nano v3.

The idea behind the circuit is:

Use the NewPing library to generate a distance measurement in centimeters.

Print the distance value to the screen, and keep on repeating.

As the sensor is moved around (8V lipo battery connected to Vin and Ground) you can see the distance updated on the tiny screen.

Gets your robot up and running through a Python App
UPDATE : 7/14/2014 : 1) Controlling a robot via a Python GUI added 2) Video demonstrating GUI control added. Read more

Homemade Laser Rangefinder

My laser range finder got a lot of interest so I thought I'd try to explain it in more detail.

Laser_rangefinder.jpg

It's not finished yet as it still needs to be mounted on it's stepper motor with a home position switch.

The sensor side has been tested on an oscilliscope. When I moved my hand in front of it, the pulse width varied to match.  Below is a diagram showing how the sensor works.