In this instructable, I will show you how to control outputs using PWM. The circuit that I am using uses a transistor rated at 700 mA. To control devices that use higher voltage/amperage, you will also need a relay.
Pulse Width Modulation simply turns an output on and of rapidly, which can be used for dimming LED's and changing speed on motors.
Step 1: Parts and Tools
Here are the parts and tools needed to build this project:
NPN transistor I'm using a (2222a)
1k Ohm resistor
Linkit ONE board
Small DC motor (Or any kind of output) OR an LED
Computer with linkit ONE drivers and latest version of the Arduino IDE
Step 2: Wiring
For this step, you can choose the difficulty, you can either plug the led directly into pin 9, or connect a transistor to control higher powered things, like motors.
LED: Put the ground pin of the LED (the shorter one) into the GND pin on the board, and the longer lead into pin 9 on the board.
Transistor: Plug the base of the transistor (centre pin) into pin 9 remembering to add a 1k resistor in between, then the emitter (right pin) to a ground pin, and the collector to the negative pin of the device that you are driving. In my case, the negative lead of a motor. Onto the next step.