// ============================================================================= // esp32_hf_tuner.ino — Main Firmware for HF L/T/Pi Antenna Tuner // Project: RF-HFTuner / Motorized Antenna Tuner Suite // Device: ESP32-WROOM-32 // Rev: 1.0 2026-05-01 // // Libraries required (Arduino Library Manager): // AccelStepper >= 1.64.0 (Mike McCauley) // BluetoothSerial (ESP32 built-in, esp32 board package) // WiFi (ESP32 built-in) // WebServer (ESP32 built-in) // ArduinoJson >= 6.21.0 (Benoit Blanchon) // Preferences (ESP32 built-in) // Adafruit_SSD1306 >= 2.5.7 (Adafruit) // Adafruit GFX Library >= 1.11.9 (Adafruit) // Wire (ESP32 built-in) // // Pinout: see config.h // ============================================================================= #include #include #include #include #include #include #include #include #include #include #include "config.h" #include "swr.h" #include "tuner.h" // ============================================================================= // GLOBAL OBJECTS // ============================================================================= // Stepper motors (AccelStepper, DRIVER mode: external step/dir) AccelStepper stepperCap(AccelStepper::DRIVER, PIN_CAP_STEP, PIN_CAP_DIR); AccelStepper stepperInd(AccelStepper::DRIVER, PIN_IND_STEP, PIN_IND_DIR); // SWR measurement SWRMeter swrMeter; // Auto-tuner AutoTuner autoTuner; // Position managers CapPositionManager capMgr; InductorPositionManager indMgr; // Network (relay) controller NetworkController netCtrl; // Command parser TunerCommandParser cmdParser; // Band preset storage BandPresetStore presetStore; // Bluetooth Serial (SPP) BluetoothSerial SerialBT; // Web server on port 80 WebServer webServer(HTTP_PORT); // Non-volatile storage Preferences prefs; // OLED display (SSD1306, 128×64, I2C) Adafruit_SSD1306 oled(OLED_WIDTH, OLED_HEIGHT, &Wire, -1); // ============================================================================= // STATE VARIABLES // ============================================================================= FirmwareState firmwareState = STATE_INIT; int currentBand = BAND_40M; uint32_t lastSWRUpdate = 0; uint32_t lastOLEDUpdate = 0; uint32_t lastStatusBroadcast = 0; uint32_t lastLEDToggle = 0; bool ledState = false; float cachedSWR = 0.0f; float cachedFwdW = 0.0f; String btBuffer = ""; String serialBuffer = ""; bool homingDone = false; // ============================================================================= // HTML CONTROL PAGE (stored in PROGMEM to save heap) // ============================================================================= static const char HTML_PAGE[] PROGMEM = R"rawhtml( RF-HFTuner Control

RF-HFTuner

Motorized HF Antenna Tuner — 192.168.4.1

SWR Meter

--.-

FWD Power

-- W

Refl Power

-- W

Return Loss

-- dB

Gamma

Tuner State

Inductance

-- µH

Capacitance

-- pF

Band

Network

State

Manual L/C Control

Inductance: 0.0 µH

Capacitance: 10 pF

Band Select

160m

80m

60m

40m

30m

20m

17m

15m

12m

10m

6m (50 MHz)

Network Topology

Actions

Log

RF-HFTuner v1.0 — Updated: --

)rawhtml"; // ============================================================================= // SETUP // ============================================================================= void setup() { Serial.begin(115200); Serial.println("\n\n=== RF-HFTuner v" FW_VERSION_STRING " ==="); Serial.println("Device: " DEVICE_NAME); // --- Status LED --- pinMode(PIN_LED_STATUS, OUTPUT); digitalWrite(PIN_LED_STATUS, HIGH); // --- Limit switch GPIO (input-only, external pull-ups) --- pinMode(PIN_CAP_MIN, INPUT); pinMode(PIN_CAP_MAX, INPUT); pinMode(PIN_IND_MIN, INPUT); pinMode(PIN_IND_MAX, INPUT); // --- Band selector GPIO --- pinMode(PIN_BAND_BIT0, INPUT_PULLDOWN); pinMode(PIN_BAND_BIT1, INPUT_PULLDOWN); pinMode(PIN_BAND_BIT2, INPUT_PULLDOWN); pinMode(PIN_BAND_BIT3, INPUT_PULLDOWN); // --- NVS --- prefs.begin(NVS_NAMESPACE_CONFIG, false); currentBand = prefs.getInt(NVS_KEY_LAST_BAND, BAND_40M); Serial.print("Restoring band: "); Serial.println(BAND_TABLE[currentBand].name); // --- I2C & OLED --- Wire.begin(PIN_I2C_SDA, PIN_I2C_SCL); if (!oled.begin(SSD1306_SWITCHCAPVCC, OLED_I2C_ADDR)) { Serial.println("WARN: OLED not found"); } else { oled.clearDisplay(); oled.setTextSize(1); oled.setTextColor(SSD1306_WHITE); oled.setCursor(0, 0); oled.println("RF-HFTuner v" FW_VERSION_STRING); oled.println("Initializing..."); oled.display(); } // --- Capacitor stepper --- stepperCap.setMaxSpeed(2000.0f); stepperCap.setAcceleration(500.0f); stepperCap.setEnablePin(PIN_CAP_EN); stepperCap.setPinsInverted(false, false, true); // EN active-low stepperCap.disableOutputs(); // --- Inductor stepper --- stepperInd.setMaxSpeed(2000.0f); stepperInd.setAcceleration(500.0f); stepperInd.setEnablePin(PIN_IND_EN); stepperInd.setPinsInverted(false, false, true); stepperInd.disableOutputs(); // --- Position managers --- capMgr.begin(&stepperCap); indMgr.begin(&stepperInd); // --- Network controller --- netCtrl.begin(); netCtrl.setNetwork(BAND_TABLE[currentBand].preferred_net); // --- SWR meter --- swrMeter.begin(PIN_VFWD_ADC, PIN_VREV_ADC); swrMeter.loadCalibration(); // --- Auto-tuner --- autoTuner.begin(&swrMeter, &capMgr, &indMgr); // --- Band preset store --- presetStore.begin(&prefs); // --- Command parser --- cmdParser.begin(&swrMeter, &autoTuner, &capMgr, &indMgr, &netCtrl, &prefs); // --- Bluetooth SPP --- SerialBT.begin(BT_DEVICE_NAME); Serial.println("BT SPP started: " BT_DEVICE_NAME); // --- WiFi AP --- WiFi.softAP(WIFI_SSID, WIFI_PASSWORD, WIFI_CHANNEL, 0, WIFI_MAX_CLIENTS); WiFi.softAPConfig( IPAddress(192, 168, 4, 1), IPAddress(192, 168, 4, 1), IPAddress(255, 255, 255, 0) ); Serial.print("WiFi AP: "); Serial.print(WIFI_SSID); Serial.print(" IP: "); Serial.println(WiFi.softAPIP()); // --- Web server routes --- webServer.on("/", HTTP_GET, handleRoot); webServer.on("/status", HTTP_GET, handleStatus); webServer.on("/tune", HTTP_POST, handleTune); webServer.on("/setlc", HTTP_POST, handleSetLC); webServer.on("/bands", HTTP_GET, handleBands); webServer.on("/cal", HTTP_POST, handleCal); webServer.onNotFound([]() { webServer.send(404, "text/plain", "Not found"); }); webServer.begin(); Serial.println("HTTP server started"); // --- Home sequence --- Serial.println("Starting home sequence..."); oledShow("Homing...", "", "", ""); firmwareState = STATE_HOMING; bool capHomed = capMgr.homeToMin(); bool indHomed = indMgr.homeToMin(); if (capHomed && indHomed) { homingDone = true; firmwareState = STATE_IDLE; Serial.println("Homing complete."); // Load last preset float last_L, last_C, last_swr; if (presetStore.load(currentBand, &last_L, &last_C, &last_swr)) { capMgr.moveToPF(last_C); indMgr.moveToUH(last_L); Serial.printf("Restored band %s: L=%.2f µH, C=%.0f pF\n", BAND_TABLE[currentBand].name, last_L, last_C); } } else { firmwareState = STATE_FAULT; Serial.println("FAULT: Homing failed!"); } oledUpdate(); digitalWrite(PIN_LED_STATUS, LOW); Serial.println("Setup complete. Entering main loop."); } // ============================================================================= // LOOP // ============================================================================= void loop() { uint32_t now = millis(); // --- Run steppers (AccelStepper non-blocking) --- stepperCap.run(); stepperInd.run(); capMgr.update(); indMgr.update(); // --- Auto-tuner state machine --- if (autoTuner.isTuning()) { autoTuner.update(); if (!autoTuner.isTuning()) { // Tuning just finished TuningResult res = autoTuner.getResult(); if (res.success) { firmwareState = STATE_IDLE; presetStore.save(res.band, res.L_uh, res.C_pf, res.swr); prefs.putInt(NVS_KEY_LAST_BAND, currentBand); Serial.printf("AutoTune OK: SWR=%.2f L=%.2f C=%.0f\n", res.swr, res.L_uh, res.C_pf); } else { firmwareState = STATE_FAULT; Serial.println("AutoTune FAULT"); } } } // --- SWR polling --- if (now - lastSWRUpdate >= SWR_UPDATE_MS) { lastSWRUpdate = now; cachedSWR = swrMeter.readSWR(); cachedFwdW = swrMeter.readForward(); if (cachedSWR > SAFETY_MAX_SWR_FAULT && firmwareState == STATE_IDLE) { // High SWR detected; don't fault if tuning is in progress } } // --- Serial commands --- while (Serial.available()) { char c = (char)Serial.read(); if (c == '\n' || c == '\r') { if (serialBuffer.length() > 0) { String resp = cmdParser.process(serialBuffer); Serial.println(resp); serialBuffer = ""; } } else { serialBuffer += c; } } // --- Bluetooth commands --- while (SerialBT.available()) { char c = (char)SerialBT.read(); if (c == '\n' || c == '\r') { if (btBuffer.length() > 0) { String resp = cmdParser.process(btBuffer); SerialBT.println(resp); btBuffer = ""; } } else { btBuffer += c; } } // --- Web server --- webServer.handleClient(); // --- OLED update --- if (now - lastOLEDUpdate >= OLED_UPDATE_MS) { lastOLEDUpdate = now; oledUpdate(); } // --- LED blink --- ledBlink(now); } // ============================================================================= // LED BLINK HANDLER // ============================================================================= void ledBlink(uint32_t now) { uint32_t elapsed = now - lastLEDToggle; uint32_t onTime, offTime; switch (firmwareState) { case STATE_TUNING: case STATE_HOMING: onTime = LED_TUNING_ON_MS; offTime = LED_TUNING_OFF_MS; break; case STATE_FAULT: // Rapid double-blink pattern handled simply here onTime = LED_FAULT_ON_MS; offTime = LED_FAULT_OFF_MS; break; case STATE_IDLE: default: onTime = LED_IDLE_ON_MS; offTime = LED_IDLE_OFF_MS; break; } if (ledState && elapsed >= onTime) { ledState = false; digitalWrite(PIN_LED_STATUS, LOW); lastLEDToggle = now; } else if (!ledState && elapsed >= offTime) { ledState = true; digitalWrite(PIN_LED_STATUS, HIGH); lastLEDToggle = now; } } // ============================================================================= // OLED DISPLAY UPDATE // ============================================================================= void oledShow(const char* l1, const char* l2, const char* l3, const char* l4) { oled.clearDisplay(); oled.setTextSize(1); oled.setTextColor(SSD1306_WHITE); oled.setCursor(0, 0); oled.println(l1); oled.setCursor(0, 16); oled.println(l2); oled.setCursor(0, 32); oled.println(l3); oled.setCursor(0, 48); oled.println(l4); oled.display(); } void oledUpdate() { char line1[22], line2[22], line3[22], line4[22]; // Line 1: Band + frequency snprintf(line1, sizeof(line1), "%s %.3fMHz", BAND_TABLE[currentBand].name, BAND_TABLE[currentBand].freq_mhz); // Line 2: SWR if (cachedSWR >= 99.0f) snprintf(line2, sizeof(line2), "SWR: --- Fwd:%.0fW", cachedFwdW); else snprintf(line2, sizeof(line2), "SWR: %.2f Fwd:%.0fW", cachedSWR, cachedFwdW); // Line 3: L and C snprintf(line3, sizeof(line3), "L:%.2fuH C:%.0fpF", indMgr.getCurrentUH(), capMgr.getCurrentPF()); // Line 4: State + network const char* stateStr; switch (firmwareState) { case STATE_INIT: stateStr = "INIT"; break; case STATE_HOMING: stateStr = "HOMING"; break; case STATE_IDLE: stateStr = "TUNED"; break; case STATE_TUNING: stateStr = "TUNING"; break; case STATE_MOVING: stateStr = "MOVING"; break; case STATE_CALIBRATE:stateStr = "CAL"; break; case STATE_FAULT: stateStr = "FAULT"; break; default: stateStr = "???"; break; } snprintf(line4, sizeof(line4), "%s [%s]", stateStr, netCtrl.getNetworkName()); oledShow(line1, line2, line3, line4); } // ============================================================================= // WEB SERVER HANDLERS // ============================================================================= void handleRoot() { webServer.sendHeader("Cache-Control", "no-cache"); webServer.send_P(200, "text/html", HTML_PAGE); } void handleStatus() { StaticJsonDocument<512> doc; doc["swr"] = swrMeter.readSWR(); doc["fwd_w"] = swrMeter.readForward(); doc["rev_w"] = swrMeter.readReverse(); doc["return_loss"] = swrMeter.readReturnLoss(); doc["gamma"] = swrMeter.readGamma(); doc["L_uh"] = indMgr.getCurrentUH(); doc["C_pf"] = capMgr.getCurrentPF(); doc["band_index"] = currentBand; doc["band_name"] = BAND_TABLE[currentBand].name; doc["network"] = netCtrl.getNetworkName(); doc["state"] = (firmwareState == STATE_IDLE) ? "IDLE" : (firmwareState == STATE_TUNING) ? "TUNING" : (firmwareState == STATE_HOMING) ? "HOMING" : (firmwareState == STATE_FAULT) ? "FAULT" : "BUSY"; doc["uptime_ms"] = millis(); doc["fw_version"] = FW_VERSION_STRING; doc["is_tuning"] = autoTuner.isTuning(); doc["homed"] = (capMgr.isHomed() && indMgr.isHomed()); String body; serializeJson(doc, body); webServer.sendHeader("Access-Control-Allow-Origin", "*"); webServer.send(200, "application/json", body); } void handleTune() { if (!webServer.hasArg("plain")) { webServer.send(400, "application/json", "{\"message\":\"No body\"}"); return; } StaticJsonDocument<256> req; DeserializationError err = deserializeJson(req, webServer.arg("plain")); if (err) { webServer.send(400, "application/json", "{\"message\":\"JSON error\"}"); return; } StaticJsonDocument<128> resp; const char* action = req["action"] | ""; if (strcmp(action, "home") == 0) { firmwareState = STATE_HOMING; capMgr.homeToMin(); indMgr.homeToMin(); firmwareState = STATE_IDLE; resp["message"] = "Homing started"; } else if (strcmp(action, "stop") == 0) { autoTuner.stop(); stepperCap.stop(); stepperInd.stop(); firmwareState = STATE_IDLE; resp["message"] = "Stopped"; } else if (strcmp(action, "save") == 0) { int band = req["band"] | currentBand; presetStore.save(band, indMgr.getCurrentUH(), capMgr.getCurrentPF(), swrMeter.readSWR()); resp["message"] = "Preset saved"; } else if (strcmp(action, "load") == 0) { int band = req["band"] | currentBand; float L, C, swr; if (presetStore.load(band, &L, &C, &swr)) { capMgr.moveToPF(C); indMgr.moveToUH(L); resp["message"] = "Preset loaded"; } else { resp["message"] = "No preset"; } } else if (strcmp(action, "network") == 0) { int n = req["network"] | 0; netCtrl.setNetwork((NetworkType)n); resp["message"] = "Network set"; } else { // auto_tune or band select int band = req["band"] | currentBand; if (band >= 0 && band < NUM_BANDS) currentBand = band; netCtrl.setNetwork(BAND_TABLE[currentBand].preferred_net); bool doAutoTune = req["auto_tune"] | false; if (doAutoTune) { firmwareState = STATE_TUNING; if (!autoTuner.startAutoTune(currentBand)) { firmwareState = STATE_FAULT; resp["message"] = "Tune start failed"; } else { resp["message"] = "Auto-tune started"; } } else { // Just select band, load preset if available float L, C, swr; if (presetStore.load(currentBand, &L, &C, &swr)) { capMgr.moveToPF(C); indMgr.moveToUH(L); } resp["message"] = "Band selected"; } } String body; serializeJson(resp, body); webServer.sendHeader("Access-Control-Allow-Origin", "*"); webServer.send(200, "application/json", body); } void handleSetLC() { if (!webServer.hasArg("plain")) { webServer.send(400, "application/json", "{\"message\":\"No body\"}"); return; } StaticJsonDocument<128> req; deserializeJson(req, webServer.arg("plain")); float L = req["L_uh"] | indMgr.getCurrentUH(); float C = req["C_pf"] | capMgr.getCurrentPF(); capMgr.moveToPF(C); indMgr.moveToUH(L); StaticJsonDocument<64> resp; resp["message"] = "LC set"; String body; serializeJson(resp, body); webServer.sendHeader("Access-Control-Allow-Origin", "*"); webServer.send(200, "application/json", body); } void handleBands() { StaticJsonDocument<1024> doc; JsonArray arr = doc.to(); for (int i = 0; i < NUM_BANDS; i++) { JsonObject b = arr.createNestedObject(); b["index"] = i; b["name"] = BAND_TABLE[i].name; b["freq_mhz"] = BAND_TABLE[i].freq_mhz; float L, C, swr; b["has_preset"] = presetStore.load(i, &L, &C, &swr); if (presetStore.hasPreset(i)) { b["preset_swr"] = presetStore.getBestSWR(i); } } String body; serializeJson(doc, body); webServer.sendHeader("Access-Control-Allow-Origin", "*"); webServer.send(200, "application/json", body); } void handleCal() { swrMeter.calibrate(); swrMeter.saveCalibration(); StaticJsonDocument<64> resp; resp["message"] = "Calibration done"; String body; serializeJson(resp, body); webServer.sendHeader("Access-Control-Allow-Origin", "*"); webServer.send(200, "application/json", body); } // ============================================================================= // END OF esp32_hf_tuner.ino // =============================================================================