Let's Make Robots!

HC-SR04 problems

Hi all,

About a year ago I bought a HC-SR04 ultrasonic sensor, when I got it I tested it using some code I found on the internet and everything worked fine. Now I finally need to use it, I've tested it again with several different pieces of code and none of them seem to work, all I am getting is a seemingly random number that doesn't change no matter what I put in front of the sensor! However I can still hear clicking, so surely the trig pin is working fine and the issue is the echo pin? Any other ideas what the problem could be?

Thanks :)


I want one.

Just an Idea that I don't want to forget :)

Ok so I've been playing around with my losi rc car and looking for a couple of hop up parts when I came across a video

Electronic suction pads/cups ?

Hi Everyone!

Does anyone know of any cheap suction pads that can be triggered electronically? I'm looking to build a robot that can climb smooth surfaces like glass and smooth walls, and suction pads are the only method that I can think of... If not does anyone know of alternative methods? It needs to be cheap, strong and quiet though!

Edit: What about using static electricity (like rubbing a balloon so it sticks to a wall) ? Any thoughts on that idea?  

Thanks :)



Hi All,

I was wondering if any of you had ever heard of folding at home? What it is is a website where Stanford university are using the power of distributed computing to 'fold' proteins and ultimately help to solve diseases such as Alzheimer's, Huntingdon's and Parkinson's disease. 


What is this?

Hi :)

I'm trying to make a simple IR transmitter and receiver circuit using the RX-B and the TX-2B chips. (http://www.elenota.pl/upload/TX-2B(RX-2B)AY.pdf on page 7) but I am unsure as to what the symbol with fosc=114Khz next to it means. It looks a bit like the symbol for a pot, and I'm assuming it has something to do with frequency? Any ideas?

Thanks :)



I was wondering how many of you guys used linux? I use Ubuntu on my laptop, but am ashamed to admit that I have to use Windows on my desktop for things like, well just sketchup... 

So how many of you use linux and which distro do you use and why ? :)

A complete new update :) Since the old robotic arm was so terrible I decided to spend a pound or two on some acrylic and make robot arm version two, and here it is. … Read more