Checkpoint 2: Make the light blink

Goals:

· Learn how to create an Arduino program (known as a sketch),

· Learn how to upload an Ardunio program onto the Arduino board,

· Make an LED blink in a controlled fashion.

Step 1: Create the following circuit using your Arduino development board. As always, ask for help when you need it.

Note that in this case we are using a Resistor as a current limiter. Once you look up the specs of your device, you can choose a resistor that will give you a desired voltage via V=IR. In our case our LED’s spec sheet suggests a current of 1mA. The Arduino’s voltage is 5 Volts. This means that a 500Ohm resistor will give us the desired current. There are a variety of classes offered to help you learn more about circuits. For this workshop it is ok to follow the suggestions in this packet or to ask for help.

Step 2: Plug the Arduino into the computer via the USB port. If the USB port is working correctly, the green “ON” light on the UNO should come on. The first time you do this, the computer might also install drivers.

Step 3: Open up arduino.exe to write a new sketch.

Step 4: Make sure that under “Tools” you select the correct Board. Also under “Tools” make sure that you select the correct COM port – you can either simply guess the correct port and then try another one if your first guess doesn’t work, or, you can go to your computer’s hardware settings control panel to figure it out

Step 5: Type your program into the sketch area. Note that there are many example programs under “File”, “Example”. Below is a very basic “blink” program – a variation of this program should be available in the Example menu – or, you can type it in yourself:

/*Blink

Turns on an LED on and off repeatedly.

*/

void setup() {

// First, you must initialize the digital pin as an output.

// Note that Pin13 has an LED connected on most Arduino boards:

pinMode(13, OUTPUT);

}

void loop() {

digitalWrite(13, HIGH); // set the LED on

delay(1000); // wait for 1000ms

digitalWrite(13, LOW); // set the LED off

delay(1000); // wait for 1000ms

}

Step 6: Upload your program to the Arduino by clicking the “Upload” button. As you Upload the program, you should notice that one of the LEDs built into the board blinks rapidly.

Step 7: To convince yourself that you are really making the light blink the way you are meaning to, attempt to reprogram the Arduino to change the blink rate in a variety of ways.

Step 8: If time permits, borrow or purchase a 3-color LED and have fun experimenting.

Troubleshooting:

Some problems can be fixed by…:

a) …making sure that your computer has administrator rights to allow programs to run.

b) …going to the “device manager” and making sure that the Arduino is working properly and the drivers are correctly installed.