For that assignment I decided to make a Neil's Charlieplex LED Array.
Using charlie plexing we can simply increase the number of LED's we can drive with a limited number of microcontroller pins. the good thing about this
system is that we can control 20 leds mesh with only 5 pins.
Milling, and Soldering
First of all i downloaded the images of the board, and i milled and then i soldered.
Download: Board, Traces, Cut.
- Is not a complicated board but it's very entertaining welding, has about 50 components to solder!
- Take your time and do not despair.
- Be careful to not join two welds, because the LEDs and resistors are close together.
Connecting to battery
I used a 9v battery, to provide voltage to the board.
Be careful with the polarity of the battery!! The first time that I connected the battery to the board, something bad happened.
White smoke came out of the voltage regulator and burned it completely.
I had to replace a new one noticing as i connect the positive and negative pole correctly.
Attached is a picture which is connected properly.
Programing Neil's code
Just i downloaded the C and make files and i tested.
I followed the normal steps to program by Cygwin:
- make -f ***.make
- make -f ***.make program-usbtiny
Programing Mari Robles code
To better understand how it worked the Neil's code, I decided to find another example and compare them to decipher each part.
I found this code in Mari Robles 's webpage. This code provides the possibility to write letters on the LED array.
I have not had time to edit but I hope to do soon.