Hello, this is my first instructable and I hope you like it. It's a simple project, using MAKE Controller (a very useful controller from www.makezine.com), that makes a persistence-of-vision-effect using LEDs. When you move the board quickly you can see two parallel lines drawing 'mountains' or continuous triangles.
The list of materials:
2 220ohm resistors
Step 1: Preparing the Circuit
First, you'll have to take 4 LEDs, 1 220ohm resistor and a few cm of wire and make the circuit shown below. When you finish the first circuit, just make a second one.
Step 2: Connecting to the Board
Now, you have to attach the two circuits to the board. One to the first 4 digital outs (0-3), and the other to the 4-7 digital outs.
Step 3: Programming the Board
Now, we have to code the little task that will make the effect. I attached a '.c' file with the code and the instructions inside.
Notice that you'll need the Make Controller firmware source code, downloadable from http://www.makingthings.com/makecontrollerkit/software/index.htm. You may also want to have a C editor. For the MAKE Controller source code I really recommend you CrossStudio (http://www.rowley.co.uk/arm/) because it includes the source editor, a compiler, and the project manager. There's an alternative instead: using GNU ARM compiler together with cygwin. Read the make controller tutorials to get more information about these topics ;-)
Step 4: Upload the Firmware and Test!
And... that's all. You could improve it a lot, for example make the first line green and the second red, or make a character display, showing a message.
If you have found any mistake, please let me know so I can correct it. I'm also open to suggestions ;-)