Traffic light with stop request
Probably one of the most easier project I've made since a while... you don't have to be an electronic engineer to make something like this, but if you want to get into the world of Arduino and the DIY electronics stuff, you could find this experiment pretty useful. In this circuit, as you can see by the photos, there are two pseudo-traffic lights, which are synchronized among them, and it's also placed a push button which will be used as a stop request made by a pseudo-pedestrian :-)
The first series of LEDs will be used for the pedestrians, and the second one for the vehicles. When you push the push button, the delay of the traffic light for the pedestrians with the red light, will be lower and so faster than the normal delay of a traffic light without stop request. It is also connected a 2.2kOhm resistor before the check led, which is yellow in the picture, and a speaker which will be used as a sound notification.
Here's a simple demonstration:
[here] you can find the Arduino sketch to upload on your Arduino board...
Oh, if you want you can leave a comment on the [Fritzing.org] website, where I also uploaded this project ;-)