Tag Archives: Arduino Nano

Buzz like a UPS

This is yet another simple test of a new hardware component that I haven’t played with before. Buzzer is an audio device which may be mechanical, electromechanical, or piezoelectric. It can generate from quite awful UPS-like siren to melodious tone; it really depends on how you want to use it. I just wanted to make noise like that of a UPS does when electricity goes off.

The rest of the post can be found here.

Blinking BiPolar LED

BiPolar LEDs have 3 three legs. One goes to ground, and the other 2 represents two different colors in the same LED. In my case, they are green and red. I have also used a variant of Arduino Nano in order to reduce the size of the experiment. Here’s the list of connections that I have made:

LED’s ground leg 220 ohm resistor
220 ohm resistor Arduino’s ground
LED’s one leg Arduino’s Digital Pin 12
LED’s other leg Arduino’s Digital Pin 13

My intention was to blink the colors alternatively. Green, red, green, red, green… with a 1-second delay in between. The code is as simple as one can imagine. There’s really nothing novel going on here:

int green = 12;
int red = 13;

void setup() {                
  pinMode(green, OUTPUT);     
  pinMode(red, OUTPUT);

void loop() {
  digitalWrite(green, HIGH);
  digitalWrite(red, LOW);

  digitalWrite(green, LOW);
  digitalWrite(red, HIGH);

Here’s the final outcome: