Linkit ONE: Solving Low LED Brightness Problem

For all of you who have used the Mediatek Linkit ONE, you may have noticed that whenever you connect an LED to a digital pin, it's brightness is very low.

This happens because the output current voltage of linkit one's digital pin is very low as compared to arduino (3.3v, 2-3mA). This problem can be solved by using an NPN transistor for each digital pin. This instructable will guide you the same.

So let's get started.......

The following parts are required for attempting this instructable:

- Linkit ONE
- Battery
- Breadboard
- LEDs (As many as you want)
- BC547 transistors (= no. of LEDs)
- Jumper wires

The first very basic step for each Linkit ONE project is to connect the battery. Do so by simply plugging it to it's respective socket.

The next step is to connect all the LEDs to your Linkit ONE. You can use any number of LEDs from 1-12 but keep in mind that you must have a transistor for each.

Connect evertyhing as per the image given above. Use a breadboard and jumper wires to connect the LEDs.

Upload the code given below to your Linkit one. The switches should be in SPI, UART, and USB modes.

\\
void setup()
pinMode(2, OUTPUT);
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
pinMode(6, OUTPUT);
pinMode(7, OUTPUT);
void loop()
{
digitalWrite(2, HIGH);
digitalWrite(3, HIGH);
digitalWrite(4, HIGH);
digitalWrite(5, HIGH);
digitalWrite(6, HIGH);
digitalWrite(7, HIGH);
delay(3000);
digitalWrite(2, LOW);
digitalWrite(3, LOW);
digitalWrite(4, LOW);
digitalWrite(5, LOW);
digitalWrite(6, LOW);
digitalWrite(7, LOW);
delay(3000);
}
\\

Finally, switch your Linkit ONE on. All the LEDs will now blink every 3 seconds but their brighness will be much higher than before.

So this is the end of this instructable. Thanks for watching!!