Lab 2: Digital I/O Breakout Boards
In this lab you will get set up with the Arduino prototyping environment and explore digital inputs and outputs using a microcontroller. You will also learn to solder and create two custom breakout boards, one input and one output.
Digital I/O Circuit
For this part of the lab, the idea was to use two buttons or switches in order to control a strip of NeoPixels through the use of an Arduino program. First, I soldered three wires to the end of the NeoPixel strip, one for power, one for ground, and a signal wire to connect directly to the Arduino. Then I connected my Arduino to the computer and ran a preset sketch just to test and see if my NeoPixels were working.
Quick schematic drawing of the circuit
Testing the NeoPixels first
After I got my NeoPixels to light up, I added another button and slightly changed the configuration. I had some trouble with my buttons at first, but I realized that I just had them turned sideways. Once I got my buttons in the right configuration, the code that I had written started to work. The red button turns the strips from the bottom to the top to one color, the black button turns the button to another color, and I tried to write code for when both buttons are pushed, and it worked! When neither of the buttons are pushed, the NeoPixels are off.
Final Code for the NeoPixels (scroll)
Soldered Breakout Boards
Digital Input Breakout Board
For the input breakout board, I soldered a wire to the two the outside pegs on a switch, and soldered a resistor (a standard 10K for the Arduino) to the middle peg. So there were three wires coming from this breakout board; power, ground and signal (which goes to a pin on the Arduino)
Schematic drawing of the digital input circuit
Back of the input board
Front of the input board
Digital Output Breakout Board
For the output breakout board, I soldered a wire to a resistor, and then soldered that to 2 LEDs that were in a series. Using Ohms law, I found out that I would need a resistor of about 50K, but I went up and used a 100 Ohm one. This breakout board was much more confusing together, so I made sure to keep all of the wires organized so I would mix anything up.
Schematic drawing of the digital output circuit
Back of the output board
Front of the output board
Then I connect one of the outside wires from the input board to the power pin on the Arduino, and I put the other one in a ground pin, then I stuck the signal wire into a pin. Then I took the side of the output board that would take in the power and lead to the resistors/LEDs and chose another pin. Lastly I put the second wire on another grounding pin. Then I wrote some simple code to turn the LED's on digitally from the switch. Since I had done the NeoPixels first, this part of the lab made so much more sense, and the code was decently easy to figure out.
