Week10

# Week10 Output Devices

SSTM

Group Assignment: — on progress

Individual Assignment:

• Add an output device to a self-designed microcontroller board, my PCB board ready and am on searching from different source for XIAO ESP 32 C3
• Program the device to perform a specific action … I did to align the Alarm system with my FP and Buzzer as output device.

---

1. Introduction to Output Devices

Output devices are components that receive signals from a microcontroller and convert them into physical actions such as light, sound, or movement.

---

2. Selected Output Devices

• LED → Visual alert
• Buzzer → Sound alarm

---

3. Circuit Connection

• LED → Pin 8
• Buzzer → Pin 9
• Both connected to GND

---

4. Arduino Code to learn the output devices with code integration

// ===== PIN DEFINITIONS =====
int CLK = 2;        // Rotary encoder CLK pin (signal A)
int DT = 3;         // Rotary encoder DT pin (signal B)
int SW = 4;         // Rotary encoder push button

int redPin = 9;     // RGB LED - Red channel (PWM)
int greenPin = 10;  // RGB LED - Green channel (PWM)
int bluePin = 11;   // RGB LED - Blue channel (PWM)

// ===== STATE VARIABLES =====
int currentStateCLK;    // current reading of CLK
int lastStateCLK;       // previous reading of CLK

int brightness = 150;   // LED brightness (0–255)
int hue = 0;            // color position (0–360 degrees)

bool mode = 0;          // 0 = color mode, 1 = brightness mode

// ===== SETUP FUNCTION =====
void setup() {

  pinMode(CLK, INPUT);        // encoder CLK as input
  pinMode(DT, INPUT);         // encoder DT as input
  pinMode(SW, INPUT_PULLUP);  // button with internal pull-up

  pinMode(redPin, OUTPUT);    // RGB red output
  pinMode(greenPin, OUTPUT);  // RGB green output
  pinMode(bluePin, OUTPUT);   // RGB blue output

  Serial.begin(9600);         // start serial communication

  lastStateCLK = digitalRead(CLK); // store initial CLK state
}

// ===== MAIN LOOP =====
void loop() {

  currentStateCLK = digitalRead(CLK); // read encoder rotation

  // ===== DETECT ROTATION =====
  if (currentStateCLK != lastStateCLK) {   // if rotation detected

    if (digitalRead(DT) != currentStateCLK) {
      // Clockwise rotation

      if (mode == 0) {
        hue += 5;          // change color smoothly
      } else {
        brightness += 10;  // increase brightness
      }

    } else {
      // Counterclockwise rotation

      if (mode == 0) {
        hue -= 5;          // reverse color direction
      } else {
        brightness -= 10;  // decrease brightness
      }
    }

    // ===== LIMIT VALUES =====
    brightness = constrain(brightness, 0, 255); // keep valid PWM range
    hue = (hue + 360) % 360;                    // keep hue in 0–359

    // ===== DEBUG OUTPUT =====
    Serial.print("Mode: ");
    Serial.print(mode);          // show current mode
    Serial.print(" | Brightness: ");
    Serial.print(brightness);    // show brightness value
    Serial.print(" | Hue: ");
    Serial.println(hue);         // show color position
  }

  lastStateCLK = currentStateCLK; // update state

  // ===== BUTTON MODE SWITCH =====
  if (digitalRead(SW) == LOW) {  // button pressed
    delay(200);                  // debounce delay
    mode = !mode;                // toggle mode
  }

  // ===== UPDATE RGB OUTPUT =====
  HSVtoRGB(hue, brightness);     // convert and apply color
}

// ===== HSV → RGB FUNCTION =====
void HSVtoRGB(int hue, int value) {

  float h = hue / 60.0;   // divide color wheel into 6 regions
  int i = floor(h);       // get region index
  float f = h - i;        // fractional part

  int p = 0;              // base value (no color)
  int q = value * (1 - f);
  int t = value * f;

  // ===== SELECT COLOR REGION =====
  switch(i % 6) {
    case 0: setRGB(value, t, p); break; // Red → Yellow
    case 1: setRGB(q, value, p); break; // Yellow → Green
    case 2: setRGB(p, value, t); break; // Green → Cyan
    case 3: setRGB(p, q, value); break; // Cyan → Blue
    case 4: setRGB(t, p, value); break; // Blue → Magenta
    case 5: setRGB(value, p, q); break; // Magenta → Red
  }
}

// ===== APPLY RGB VALUES =====
void setRGB(int r, int g, int b) {

  analogWrite(redPin, r);     // set red brightness
  analogWrite(greenPin, g);   // set green brightness
  analogWrite(bluePin, b);    // set blue brightness
}

Code source AI (with prompt “generate and write a code for RGB LED control with Rotary) **

RGB SYS

---

5. How the Code Works

• The microcontroller continuously runs the loop() function
• It turns ON the LED and buzzer for 1 second
• Then turns them OFF for 1 second
• This repeats forever creating a blinking + beeping alert

---

7. Result

• LED blinks successfully
• Buzzer produces sound
• Outputs respond correctly to microcontroller signals

src=”Images/w10_image/Scanned_Mouse(1).mp4”

---

8. Conclusion

This assignment demonstrates how to:

• Control output devices
• Program microcontroller responses
• Build a simple RGB with rotary control system