ESP32 펌웨어 - DIY RF 버그 탐지기용

/* * ESP32 RF Bug Detector * * Hardware: * - AD8317 logarithmic RF detector on analog pin 34 * - SSD1306 OLED screen on I2C pins 21 and 22 * - Buzzer on pin 25 * - Calibration button on pin 4 * - LiPo battery powered * * Tuning parameters are marked with [TUNE] comments. */ #include <Wire.h> #include <Adafruit_SSD1306.h> #include <Adafruit_GFX.h> // OLED configuration #define SCREEN_WIDTH 128 #define SCREEN_HEIGHT 64 #define OLED_ADDR 0x3C Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1); // Pin definitions #define RF_DETECTOR_PIN 34 #define BUZZER_PIN 25 #define CAL_BUTTON_PIN 4 // [TUNE] AD8317 characteristics // AD8317 output is typically 0.5V to 2.5V for -60dBm to +10dBm // Slope: ~22mV/dB, Intercept: ~-60dBm at 0.5V #define AD8317_SLOPE_MV_PER_DB 22.0 #define AD8317_INTERCEPT_DBM -60.0 #define AD8317_VREF 0.5 // Reference voltage at intercept // [TUNE] Sampling and timing #define SAMPLE_RATE_HZ 20 #define SAMPLE_INTERVAL_MS (1000 / SAMPLE_RATE_HZ) // [TUNE] Buzzer behavior #define MIN_BEEP_INTERVAL_MS 500 // Slowest beep (weak signal) #define MAX_BEEP_INTERVAL_MS 50 // Fastest beep (strong signal) #define BEEP_DURATION_MS 30 // Length of each beep // [TUNE] Display thresholds #define BAR_MIN_DBM -70.0 // Bottom of bar graph #define BAR_MAX_DBM -20.0 // Top of bar graph #define ALERT_THRESHOLD_DB 6.0 // dB above baseline to trigger alert // Calibration state float baseline_dbm = -60.0; // Default baseline bool calibrated = false; unsigned long last_cal_time = 0; // Timing variables unsigned long last_sample_time = 0; unsigned long last_beep_time = 0; // Signal processing float current_dbm = 0.0; float smoothed_dbm = 0.0; float alpha = 0.3; // [TUNE] Smoothing factor (0.1-0.5) void setup() { Serial.begin(115200); // Initialize pins pinMode(BUZZER_PIN, OUTPUT); pinMode(CAL_BUTTON_PIN, INPUT_PULLUP); analogReadResolution(12); // ESP32 ADC is 12-bit // Initialize OLED Wire.begin(21, 22); if (!display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR)) { Serial.println("SSD1306 allocation failed"); for (;;); // Don't proceed if OLED fails } display.clearDisplay(); display.setTextSize(1); display.setTextColor(SSD1306_WHITE); // Show startup screen display.setCursor(20, 25); display.println("RF Bug Detector"); display.setCursor(30, 40); display.println("Starting..."); display.display(); delay(1000); // Initial calibration after 2 seconds delay(2000); calibrateBaseline(); } void loop() { unsigned long now = millis(); // Sample at fixed rate if (now - last_sample_time >= SAMPLE_INTERVAL_MS) { last_sample_time = now; // Read and convert to dBm int raw = analogRead(RF_DETECTOR_PIN); float voltage = (raw / 4095.0) * 3.3; current_dbm = voltageToDbm(voltage); // Apply smoothing smoothed_dbm = (alpha * current_dbm) + ((1.0 - alpha) * smoothed_dbm); // Update display updateDisplay(); // Update buzzer updateBuzzer(); } // Check calibration button (debounced) if (digitalRead(CAL_BUTTON_PIN) == LOW && (now - last_cal_time > 500)) { last_cal_time = now; calibrateBaseline(); } } float voltageToDbm(float voltage) { // [TUNE] Adjust this conversion for your specific AD8317 // Formula: dBm = (V - VREF) / slope + intercept // For AD8317: slope is ~22mV/dB, VREF is 0.5V at -60dBm float dbm = ((voltage - AD8317_VREF) * 1000.0 / AD8317_SLOPE_MV_PER_DB) + AD8317_INTERCEPT_DBM; return dbm; } void calibrateBaseline() { // Average several readings for stable baseline float sum = 0.0; int samples = 20; for (int i = 0; i < samples; i++) { int raw = analogRead(RF_DETECTOR_PIN); float voltage = (raw / 4095.0) * 3.3; sum += voltageToDbm(voltage); delay(10); } baseline_dbm = sum / samples; calibrated = true; // Visual feedback on OLED display.clearDisplay(); display.setCursor(15, 20); display.println("Calibrated!"); display.setCursor(10, 35); display.print("Baseline: "); display.print(baseline_dbm, 1); display.println(" dBm"); display.display(); delay(1000); } void updateDisplay() { display.clearDisplay(); // Title display.setCursor(0, 0); display.print("RF Detector"); // Signal strength value display.setCursor(0, 10); display.print("Signal: "); display.print(smoothed_dbm, 1); display.print(" dBm"); // Baseline indicator display.setCursor(0, 20); display.print("Base: "); display.print(baseline_dbm, 1); display.print(" dBm"); // Alert indicator if (calibrated && (smoothed_dbm > (baseline_dbm + ALERT_THRESHOLD_DB))) { display.setCursor(80, 20); display.print("ALERT!"); } // Bar graph int bar_width = SCREEN_WIDTH - 10; int bar_height = 20; int bar_x = 5; int bar_y = 35; // Draw bar background display.drawRect(bar_x, bar_y, bar_width, bar_height, SSD1306_WHITE); // Calculate bar fill based on dBm range float bar_percent = (smoothed_dbm - BAR_MIN_DBM) / (BAR_MAX_DBM - BAR_MIN_DBM); bar_percent = constrain(bar_percent, 0.0, 1.0); // Fill bar int fill_width = (int)(bar_percent * (bar_width - 2)); if (fill_width > 0) { display.fillRect(bar_x + 1, bar_y + 1, fill_width, bar_height - 2, SSD1306_WHITE); } // Draw scale markers for (int i = 0; i <= 4; i++) { int marker_x = bar_x + (i * (bar_width - 2) / 4); display.drawLine(marker_x, bar_y + bar_height, marker_x, bar_y + bar_height + 3, SSD1306_WHITE); } // Scale labels display.setCursor(5, 58); display.print((int)BAR_MIN_DBM); display.setCursor(100, 58); display.print((int)BAR_MAX_DBM); display.display(); } void updateBuzzer() { // Calculate beep interval based on signal strength float signal_above_baseline = smoothed_dbm - baseline_dbm; // [TUNE] Adjust these thresholds for your environment float min_signal = 0.0; // dB above baseline for slowest beep float max_signal = 20.0; // dB above baseline for fastest beep // Map signal strength to beep interval float beep_interval = mapFloat(signal_above_baseline, min_signal, max_signal, MIN_BEEP_INTERVAL_MS, MAX_BEEP_INTERVAL_MS); beep_interval = constrain(beep_interval, MAX_BEEP_INTERVAL_MS, MIN_BEEP_INTERVAL_MS); // Only beep if signal is above baseline if (signal_above_baseline > 0.5) { unsigned long now = millis(); if (now - last_beep_time >= beep_interval) { last_beep_time = now; tone(BUZZER_PIN, 2000, BEEP_DURATION_MS); // [TUNE] Adjust frequency } } else { // No beep when below baseline noTone(BUZZER_PIN); } } float mapFloat(float x, float in_min, float in_max, float out_min, float out_max) { return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min; }