Initial commit

dcf77.ino

@@ -0,0 +1,129 @@
+const int signalPin = 0;
+const int sampleInterval = 10; // milliseconds
+const int ledPin = 13;
+
+int secondIndex = -1;
+byte bits[59]; // being lazy
+int lastValue;
+unsigned long lowStart = 0;
+unsigned long highStart = 0;
+int ledState = LOW;
+
+int readSignalPin() {
+  return analogRead(signalPin) > 400 ? LOW : HIGH;
+}
+
+boolean sampleSignal() {
+  boolean result = false;
+  int value = readSignalPin();
+
+  if (lastValue == HIGH) {
+    if (value == LOW) { // new second starts
+      Serial.println("new second starts");
+      unsigned long time = millis(); // FIXME: need to handle overflow
+
+      lowStart = time;
+
+      if (highStart > 0) {
+        unsigned long highDuration = time - highStart;
+
+        if (highDuration > 1500) { // new minute starts
+          Serial.println("new minute starts");
+          secondIndex = 0;
+        }
+      }
+
+      if (ledState == LOW) {
+        ledState = HIGH;
+      } else {
+        ledState = LOW;
+      }
+
+      digitalWrite(ledPin, ledState);
+    }
+  }
+  else { // lastValue == LOW
+    if (value == HIGH) {
+      unsigned long time = millis(); // FIXME: need to handle overflow
+
+      highStart = time;
+
+      if (lowStart > 0 && secondIndex >= 0 && secondIndex <= 58) {
+        unsigned long lowDuration = time - lowStart;
+
+        if (lowDuration < 150) { // bit is 0
+          Serial.println("bit is 0");
+          bits[secondIndex] = 0;
+        }
+        else { // bit is 1
+          Serial.println("bit is 1");
+          bits[secondIndex] = 1;
+        }
+
+        ++secondIndex;
+
+        if (secondIndex == 59) {
+          result = true;
+        }
+      }
+    }
+  }
+
+  lastValue = value;
+
+  return result;
+}
+
+void setup() {
+  Serial.begin(115200);
+  Serial.println("setup");
+
+  pinMode(ledPin, OUTPUT);
+
+  lastValue = readSignalPin();
+}
+
+void loop() {
+  delay(sampleInterval); // FIXME: need to account for the actual time it takes to do the sampling
+
+  if (sampleSignal()) {
+    Serial.print("full: ");
+
+    for (int i = 0; i < 59; ++i) {
+      Serial.print(bits[i]);
+      Serial.print(" ");
+    }
+
+    Serial.println("");
+
+    int day = bits[41] * 20 + bits[40] * 10 + bits[39] * 8 + bits[38] * 4 + bits[37] * 2 + bits[36] * 1;
+    int month = bits[49] * 10 + bits[48] * 8 + bits[47] * 4 + bits[46] * 2 + bits[45] * 1;
+    int year = bits[57] * 80 + bits[56] * 40 + bits[55] * 20 + bits[54] * 10 + bits[53] * 8 + bits[52] * 4 + bits[51] * 2 + bits[50] * 1;
+    int hour = bits[34] * 20 + bits[33] * 10 + bits[32] * 8 + bits[31] * 4 + bits[30] * 2 + bits[29] * 1;
+    int minute = bits[27] * 40 + bits[26] * 20 + bits[25] * 10 + bits[24] * 8 + bits[23] * 4 + bits[22] * 2 + bits[21] * 1;
+
+    Serial.print(day);
+    Serial.print(".");
+
+    if (month < 10) {
+      Serial.print(0);
+    }
+
+    Serial.print(month);
+    Serial.print(".");
+
+    Serial.print("20");
+    Serial.print(year);
+    Serial.print(" ");
+
+    Serial.print(hour);
+    Serial.print(":");
+
+    if (minute < 10) {
+      Serial.print(0);
+    }
+
+    Serial.print(minute);
+    Serial.println("");
+  }
+}