Test of the Electronics Project Page

Why Create This

I wanted to create this project to get back into my electronics hobby. As you can read on the electronics page, I first got into electronics / coding microcontrollers after realizing that my mechanical engineering coursework would not provide me with enough skill to build something sufficiently complex. I was interested in robotics so I ended up taking a mechatronics class during my undergraduate degree, and in this class, we coded a PIC microcontroller using BASIC to control a stepper motor and LCD screen based on inputs from a numerical keypad. Learning from the difficulty of this experience, which mainly arose due to the dearth of BASIC code to be found for controlling PICs, I decided to look into other microcontrollers. This is when I found out about Arduino and Raspberry Pis.

I created this project because it has been a while since I had really done much electronics related. Somewhat recently, I had replaced the motherboard on my 3D printer and added a BL Touch bed leveling sensor to my Creality Ender 3, but projects like these are more so following directions and just making sure that everything was put together correctly versus actually coming up with an idea, coding it, and designing the electrical system yourself. To get back into the electronics hobby, I worked with the Arduino some today. The result of me working with it can be seen below. I would have created something more complex, but I needed to move on to do something else, so I submitted what I had to this site (just to have at least one project on the site at all times).

The Project

A demonstration of the small project can be seen below. The project just outputs random colors to two RGB LEDs, controls a red LED with two switches, and plays some music on a active buzzer. The code for the project can be seen below.

RGB LED

Pulse With Modulation

Color

Switches

When you press a switch or flip a lever, these switch components connect two contacts together so that electricity can flow through them. Note: This is only for normally open switches. Using this principle and the ability to read voltage using an Arduino (see digitalRead in the code below), you can control components based on switch behavior.

Active Buzzer

Electronic buzzers are DC-powered and equipped with an integrated circuit. They are widely used in computers, printers, photocopiers, alarms, electronic toys, automotive electronic devices, telephone, timers, and other electronic products for voice devices.

Buzzers can be categorized as active and passive buzzers. The difference between the two is that an active buzzer has a built-in oscillating source, so it will generate a sound when electrified. A passive buzzer does not have such a source so it will not make a sound if DC signals are used - you have to use square waves with frequency between 2K and 5K to drive them,

Code

Explanation of Some Arduino Functions and Constants Below

The Arduino language reference can be found on this page.

• pinMode
• • Configures the pin to behave either as an INPUT or OUTPUT
• A#
• • A reference to an analog pin on the board
• OUTPUT
• • Pin used as output
• INPUT_PULLUP
• • The ATmega microcontroller on the Arduino has internal pull-up resistors (resistors that connect to power internally) that you can access. If you prefer to use these instead of external pull-up resistors, you can use the INPUT_PULLUP argument in pinMode
• analogWrite
• • Writes an analog value (PWM wave) to a pin.
• random
• • The random function generates pseudo-random numbers.
• digitalRead
• • Reads the value from the specified pin, either HIGH or LOW
• digitalWrite
• • Writes a HIGH or a LOW to a digital pin.
• delay
• • Pauses the program for the amount of time (in milliseconds) specified as parameter.

Code

int ledPin = 5; // Red LED involved with switches is connected to pin 5
int buttonApin = 9;// Button 1 connected to PIN 9
int buttonBpin = 8; // Button 2 connected to PIN 8

byte leds = 0;
int buzzer = 12;//the pin of the active buzzer

void setup() {
  // set the mode of the pins
  pinMode(A1,OUTPUT);
  pinMode(A2,OUTPUT);
  pinMode(A3,OUTPUT);
  pinMode(A4,OUTPUT);
  pinMode(A5,OUTPUT);
  pinMode(A6,OUTPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(buttonApin, INPUT_PULLUP);  
  pinMode(buttonBpin, INPUT_PULLUP);  
  pinMode(buzzer,OUTPUT);//initialize the buzzer pin as an output
}

void loop() {
  // put your main code here, to run repeatedly:
  analogWrite(A1,random(255));
  analogWrite(A2,random(255));
  analogWrite(A3,random(255));
  analogWrite(A4,random(255));
  analogWrite(A5,random(255));
  analogWrite(A6,random(255));
  if (digitalRead(buttonApin) == LOW) {
    digitalWrite(ledPin, HIGH);
  }
  if (digitalRead(buttonBpin) == LOW) {
    digitalWrite(ledPin, LOW);
  }
  unsigned char i;
  //output an frequency
  for(i=0;i<200;i++) {
    digitalWrite(buzzer,HIGH);
    delay(1);//wait for 1ms
    digitalWrite(buzzer,LOW);
    delay(1);//wait for 1ms
  }
  //output another frequency
  for(i=0;i<200;i++) {
    digitalWrite(buzzer,HIGH);
    delay(2);//wait for 2ms
    digitalWrite(buzzer,LOW);
    delay(2);//wait for 2ms
  }
  delay(100);
}

Project Video