#include #include #include #include #include #include #include #include #include "max6675.h" // ── Pinout (avoids C3 strapping pins GPIO2/8/9) ───────── #if defined(ARDUINO_ESP32C3_DEV) #define TC_SCK 4 #define TC_CS 6 #define TC_SO 5 #define OLED_SDA 10 #define OLED_SCL 7 #define BUZZER_PIN 1 #define BUTTON_PIN 3 #else #define TC_SCK 4 #define TC_CS 5 #define TC_SO 6 #define OLED_SDA 21 #define OLED_SCL 22 #define BUZZER_PIN 2 #define BUTTON_PIN 3 #endif // ── Display ───────────────────────────────────────────── #define SCREEN_WIDTH 128 #define SCREEN_HEIGHT 64 #define OLED_ADDR 0x3C // ── WiFi AP ───────────────────────────────────────────── #define AP_SSID "ClipThermo" #define AP_PASS "12345678" // ── Targets ───────────────────────────────────────────── #define TARGET_COUNT 4 float targets[TARGET_COUNT] = { 200, 250, 300, 350 }; int currentTarget = 2; // default 300°C float maxSafeTemp = 400; // ── Globals ───────────────────────────────────────────── Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1); MAX6675 thermocouple(TC_SCK, TC_CS, TC_SO); WebServer server(80); DNSServer dnsServer; float currentTemp = NAN; float maxTemp = 0; float minTemp = 9999; float lastTemp = 0; float heatRate = 0; bool targetReached = false; bool overheated = false; // ── Button state ──────────────────────────────────────── bool btnPressed = false; unsigned long btnDownTime = 0; unsigned long lastRelease = 0; bool graphMode = false; bool useFahrenheit = false; // toggle °C/°F // ── Conversion helper ─────────────────────────────────── float toDisplay(float celsius) { return useFahrenheit ? celsius * 9.0 / 5.0 + 32.0 : celsius; } const char* unitStr() { return useFahrenheit ? "F" : "C"; } // ── Graph buffer ──────────────────────────────────────── #define GRAPH_H 40 int graphY[128]; int graphIdx = 0; int graphCount = 0; // ── Timing ────────────────────────────────────────────── unsigned long lastRead = 0; unsigned long lastRate = 0; unsigned long lastDisplay = 0; unsigned long lastGraph = 0; // ── Forward declarations ─────────────────────────────── void drawScreen(); void drawGraph(); void splashScreen(); void beep(int ms); void longBeep(); void doubleBeep(); String jsonData(); // ── Setup ─────────────────────────────────────────────── void setup() { Serial.begin(115200); delay(500); // OLED Wire.begin(OLED_SDA, OLED_SCL); if (!display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR)) { Serial.println("OLED init failed!"); for (;;) delay(100); } display.clearDisplay(); display.display(); // Button + buzzer pinMode(BUTTON_PIN, INPUT_PULLUP); pinMode(BUZZER_PIN, OUTPUT); digitalWrite(BUZZER_PIN, LOW); // Graph buffer for (int i = 0; i < 128; i++) graphY[i] = -1; // WiFi AP WiFi.softAP(AP_SSID, AP_PASS); dnsServer.start(53, "*", WiFi.softAPIP()); Serial.printf("WiFi AP: %s / %s\n", AP_SSID, AP_PASS); Serial.print("IP: "); Serial.println(WiFi.softAPIP()); // Web routes server.on("/", []() { server.send(200, "text/html", R"raw( Clip Thermometer
--
--°C
Target
--°C Rate
--/s Max
--°C
--
)raw"); }); server.on("/data", []() { server.send(200, "application/json", jsonData()); }); server.begin(); // Captive portal detection — phones check these URLs server.onNotFound([]() { server.sendHeader("Location", "/", true); server.send(302, "text/plain", ""); }); splashScreen(); delay(1000); Serial.println("Clip Thermometer v3 ready"); } // ── Main Loop ─────────────────────────────────────────── void loop() { unsigned long now = millis(); // ── Button ── bool down = (digitalRead(BUTTON_PIN) == LOW); if (down && !btnPressed) { btnPressed = true; btnDownTime = now; } else if (down && btnPressed) { // Long press (>1s) = toggle graph mode if (now - btnDownTime > 1000 && !graphMode) { graphMode = true; beep(30); delay(50); beep(30); } } else if (!down && btnPressed) { btnPressed = false; unsigned long pressDuration = now - btnDownTime; unsigned long sinceLast = now - lastRelease; lastRelease = now; if (pressDuration < 1000) { if (sinceLast < 400) { // Double-click = toggle °C/°F useFahrenheit = !useFahrenheit; beep(30); delay(50); beep(30); delay(50); beep(30); } else { // Single short press = cycle target currentTarget = (currentTarget + 1) % TARGET_COUNT; targetReached = false; overheated = false; beep(50); } } if (graphMode) { graphMode = false; beep(30); } } // ── Read temperature (4Hz) ── if (now - lastRead >= 250) { lastRead = now; float raw = thermocouple.readCelsius(); if (isnan(raw) || raw < -50 || raw > 1100) { currentTemp = NAN; } else { currentTemp = raw; if (currentTemp > maxTemp) maxTemp = currentTemp; if (currentTemp < minTemp && currentTemp > 0) minTemp = currentTemp; } // Graph buffer (1 sample every 500ms) if (now - lastGraph >= 500) { lastGraph = now; if (!isnan(currentTemp)) { int graphMax = useFahrenheit ? 932 : 500; int y = map(constrain((int)toDisplay(currentTemp), 0, graphMax), 0, graphMax, GRAPH_H - 1, 0); graphY[graphIdx] = y; graphIdx = (graphIdx + 1) % 128; if (graphCount < 128) graphCount++; } else { graphY[graphIdx] = -1; graphIdx = (graphIdx + 1) % 128; } } } // ── Heating rate (1Hz) ── if (now - lastRate >= 1000 && lastRate > 0) { float dt = (now - lastRate) / 1000.0; if (!isnan(currentTemp) && !isnan(lastTemp)) { heatRate = (currentTemp - lastTemp) / dt; } lastTemp = currentTemp; lastRate = now; } if (lastRate == 0) { lastRate = now; lastTemp = currentTemp; } // ── Alarms ── if (!isnan(currentTemp) && !targetReached && !overheated) { if (currentTemp >= targets[currentTarget]) { targetReached = true; doubleBeep(); } if (currentTemp >= maxSafeTemp) { overheated = true; longBeep(); } } // ── Display ── if (now - lastDisplay >= 250) { lastDisplay = now; if (graphMode) drawGraph(); else drawScreen(); } // ── Web server ── server.handleClient(); dnsServer.processNextRequest(); } // ── Splash Screen ─────────────────────────────────────── void splashScreen() { display.clearDisplay(); display.setTextSize(1); display.setTextColor(SSD1306_WHITE); display.setCursor(10, 5); display.println("CLIP THERMOMETER"); display.drawLine(0, 17, 127, 17, SSD1306_WHITE); display.setCursor(10, 22); display.println("Hot Wire Cutter v3"); display.setCursor(10, 32); display.print("WiFi: " AP_SSID); display.setCursor(10, 42); display.print("TARGET: "); display.print((int)targets[currentTarget]); display.print("C"); display.setCursor(10, 55); display.print("Hold btn = graph"); display.display(); } // ── Normal Display ────────────────────────────────────── void drawScreen() { display.clearDisplay(); // Status bar (row 0) display.setTextSize(1); display.setCursor(0, 0); if (isnan(currentTemp)) display.print("NO PROBE"); else if (overheated) display.print("OVERHEAT!"); else if (currentTemp >= targets[currentTarget]) display.print("READY"); else display.print("HEATING"); // Heating rate (top right) if (!isnan(currentTemp)) { char buf[12]; snprintf(buf, sizeof(buf), "%+.1f/s", heatRate); int w = strlen(buf) * 6; display.setCursor(127 - w, 0); display.print(buf); } // Big temp (centered, rows ~12-48) if (isnan(currentTemp)) { display.setTextSize(2); display.setCursor(10, 24); display.print("NO PROBE"); } else { float showTemp = toDisplay(currentTemp); display.setTextSize(3); char buf[6]; snprintf(buf, sizeof(buf), "%.0f", showTemp); int w = strlen(buf) * 18; int x = (128 - w - 20) / 2; if (x < 0) x = 5; display.setCursor(x, 15); display.print(buf); // °C/°F display.setTextSize(2); display.setCursor(x + w + 2, 17); display.print(useFahrenheit ? "F" : "o"); if (!useFahrenheit) { display.setCursor(x + w + 10, 12); display.print("C"); } // Target indicator display.setTextSize(1); display.setCursor(2, 10); display.print("T:"); display.print((int)toDisplay(targets[currentTarget])); if (currentTemp >= targets[currentTarget]) display.print(" V"); } // Bottom bar: min / max display.setTextSize(1); display.setCursor(0, 56); if (!isnan(currentTemp)) { char line[22]; snprintf(line, sizeof(line), "L:%3.0f H:%4.0f M:%4.0f", minTemp > 9000 ? 0 : toDisplay(minTemp), toDisplay(maxTemp), toDisplay(maxSafeTemp)); display.print(line); } display.display(); } // ── Graph Display ─────────────────────────────────────── void drawGraph() { display.clearDisplay(); // Title display.setTextSize(1); display.setCursor(0, 0); display.print("TEMP GRAPH "); display.print(useFahrenheit ? "32-932F" : "0-500C"); // Current temp overlay if (!isnan(currentTemp)) { char buf[10]; snprintf(buf, sizeof(buf), "%.0f%s", toDisplay(currentTemp), unitStr()); int w = strlen(buf) * 6; display.setCursor(127 - w, 0); display.print(buf); } // Draw the scrolling graph int graphTop = 10; int graphH = GRAPH_H; int graphMax = useFahrenheit ? 932 : 500; // Grid lines for (int t = 0; t <= graphMax; t += graphMax / 5) { int gy = graphTop + map(t, 0, graphMax, graphH - 1, 0); if (gy >= graphTop && gy <= graphTop + graphH) { for (int x = 0; x < 128; x += 4) display.drawPixel(x, gy, SSD1306_WHITE); } } // Data line for (int i = 0; i < 128; i++) { int idx = (graphIdx - 1 - i + 256) % 128; int y = graphY[idx]; if (y >= 0) { int px = 127 - i; int py = graphTop + y; if (py >= graphTop && py < graphTop + graphH) display.drawPixel(px, py, SSD1306_WHITE); // Draw thicker line (vertical neighbor) if (py + 1 < graphTop + graphH) display.drawPixel(px, py + 1, SSD1306_WHITE); } } // Bottom info display.setTextSize(1); display.setCursor(0, 56); if (!isnan(currentTemp)) { char line[25]; snprintf(line, sizeof(line), "T:%.0f L:%.0f H:%.0f", toDisplay(targets[currentTarget]), minTemp > 9000 ? 0 : toDisplay(minTemp), toDisplay(maxTemp)); display.print(line); } display.display(); } // ── JSON API ──────────────────────────────────────────── String jsonData() { char buf[250]; snprintf(buf, sizeof(buf), "{\"c\":%s,\"cf\":%s,\"tg\":%.0f,\"r\":%.2f,\"mn\":%s,\"mx\":%s,\"safe\":%.0f,\"over\":%s,\"rdy\":%s,\"unit\":\"%s\"}", isnan(currentTemp) ? "null" : String(currentTemp, 1).c_str(), isnan(currentTemp) ? "null" : String(toDisplay(currentTemp), 1).c_str(), toDisplay(targets[currentTarget]), heatRate, minTemp > 9000 ? "null" : String(toDisplay(minTemp), 1).c_str(), String(toDisplay(maxTemp), 1).c_str(), toDisplay(maxSafeTemp), overheated ? "true" : "false", (!isnan(currentTemp) && currentTemp >= targets[currentTarget]) ? "true" : "false", unitStr() ); return String(buf); } // ── Buzzer ────────────────────────────────────────────── void beep(int ms) { digitalWrite(BUZZER_PIN, HIGH); delay(ms); digitalWrite(BUZZER_PIN, LOW); } void longBeep() { for (int i = 0; i < 3; i++) { digitalWrite(BUZZER_PIN, HIGH); delay(200); digitalWrite(BUZZER_PIN, LOW); delay(100); } } void doubleBeep() { digitalWrite(BUZZER_PIN, HIGH); delay(100); digitalWrite(BUZZER_PIN, LOW); delay(50); digitalWrite(BUZZER_PIN, HIGH); delay(200); digitalWrite(BUZZER_PIN, LOW); }