Learning Arduino – project 6 – Interactive chase light

Over the weekend i had some time to take out the Arduino board out of the box and onto my desk for some starter kit exercises.

I went trough exercise 5, which introduced the concept of a tactile button (basically just a switch). I had a bit of trouble as the diagram on the manual seems to be layed out incorrectly, i could never get it to work the way it was drawn there. It would seem that the digital pin that goes to the ground (in yellow wire in the graphic bellow), is positioned just after the resistor and connected directly to it (am i missing something?)

It was only until i did some googling and found other examples, ( this one was very useful ), where i found the correct wiring that made the tactile button work.

After this it was not hard to understand how the button worked and i moved on to project #6 on the manual, which introduces an analog input playing together with a bunch of shinny LEDS. You turn the knob and you can read it’s value and use that on your circuits. In this case, it makes the lights go faster.

At this point, i have made a couple of notes to make wiring the physical prototype easier:

• The holes in the breadboard are stiff the first time you use them. This is really annoying when you are trying to connect a resistor because its legs are very weak and will bend out of shape trying to go into the stiff hole. Also the legs are way too long and start to get in the way if you are connecting things next to them.
• The best way to prevent this is by pre-opening the breadboard holes with the tip of the jump wire before attempting to connect the resistors.
• Also it helps to cut the legs of the resistors to about half the length so they are bit sturdier and don’t bend so easily.
• Talking about jumper wires, i have separated them by length so that it’s easy to use the shorter ones whenever possible and not end up with a mess of wires all over the place.