Nano SWR Power Meter VHF

Kode Program dan Wiring

Wiring

Sensor Forward                A0           Tegangan maju (via coupler)

Sensor Reflected             A1           Tegangan pantul (via coupler)

OLED SDA            A4           Data I2C

OLED SCL             A5           Clock I2C

OLED VCC            5V           Power 5V

OLED GND           GND      Ground

Buzzer (+)           D4           Alarm SWR tinggi

Buzzer (–)           GND      Ground

 

Kode Program

#include <Wire.h>

#include <Adafruit_GFX.h>

#include <Adafruit_SSD1306.h>

 

#define PIN_FORWARD A0

#define PIN_REFLECTED A1

#define BUZZER_PIN 4

 

#define SCREEN_WIDTH 128

#define SCREEN_HEIGHT 64

#define OLED_RESET -1

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

 

// Kalibrasi daya

const float forwardScale = 1.28;

const float reflectedScale = 1.28;

 

// Fungsi pembacaan rata-rata analog

float readAverage(int pin, int samples = 10) {

  long total = 0;

  for (int i = 0; i < samples; i++) {

    total += analogRead(pin);

    delay(2); // delay kecil antar pembacaan

  }

  return (float)total / samples;

}

 

void setup() {

  Serial.begin(9600);

  pinMode(PIN_FORWARD, INPUT);

  pinMode(PIN_REFLECTED, INPUT);

  pinMode(BUZZER_PIN, OUTPUT);

  digitalWrite(BUZZER_PIN, LOW);

 

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {

    Serial.println(F("OLED tidak ditemukan"));

    while (true);

  }

 

  display.clearDisplay();

  display.display();

}

 

void loop() {

  // Baca tegangan dari coupler dengan rata-rata

  float vForward = readAverage(PIN_FORWARD) * (5.0 / 1023.0);

  float vReflected = readAverage(PIN_REFLECTED) * (5.0 / 1023.0);

 

  // Hitung daya

  float pForward = vForward * forwardScale;

  float pReflected = vReflected * reflectedScale;

 

  // Hitung SWR

  float swr;

  if (pForward == 0) {

    swr = 1.0;

  } else {

    float sqrtR = sqrt(pReflected / pForward);

    if (sqrtR >= 1.0) sqrtR = 0.999;

    swr = (1 + sqrtR) / (1 - sqrtR);

  }

 

  // Alarm jika SWR tinggi

  digitalWrite(BUZZER_PIN, (swr > 1.5) ? HIGH : LOW);

 

  // Tampilan OLED

  display.clearDisplay();

 

  // Judul

  display.setTextSize(2);

  display.setTextColor(SSD1306_WHITE);

  display.setCursor(0, 0);

  display.print("PILIHAN");

  display.setCursor(0, 16);

  display.print("ONLINE");

 

  // Data daya & SWR

  display.setTextSize(1);

  display.setCursor(0, 34);

  display.print("FWD:");

  display.print(pForward, 1);

  display.print("W");

 

  display.setCursor(64, 34);

  display.print("REF:");

  display.print(pReflected, 1);

  display.print("W");

 

  display.setCursor(0, 44);

  display.print("SWR:");

  display.print(swr, 2);

 

  // Bar SWR

  int barWidth = map(constrain(swr, 1, 5) * 10, 10, 50, 10, 120);

  display.drawRect(0, 56, 128, 6, SSD1306_WHITE);

  display.fillRect(0, 56, barWidth, 6, SSD1306_WHITE);

 

  display.display();

  delay(300);

}