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.......

Step 1: Parts Required

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

Step 2: Connect the Battery

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.

Step 3: Connect All the LEDs

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.

Step 4: Upload the Code

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);
}
\\

Step 5: Test

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!!