main.cpp

Author: jank

src/main.cpp

@@ -0,0 +1,250 @@
+#include <Arduino.h>
+#include <WiFi.h>
+
+// Mode configuration - uncomment to run in bare bone mode
+// will advance the tile every 2.5 sec.
+//#define BARE_BONE_MODE
+
+// Log configuration - comment out to get rid of any serial out
+#define DEBUG_ENABLED
+#ifdef DEBUG_ENABLED
+#define DEBUG_PRINTLN(x) Serial.println(x)
+#define DEBUG_PRINT(x) Serial.print(x)
+#else
+#define DEBUG_PRINTLN(x)
+#define DEBUG_PRINT(x)
+#endif
+
+// Board parameters
+static const int enable_pin = 21;
+static const int input1_pin = 23;
+static const int input2_pin = 22;
+
+// WiFi parameters
+static const char *ssid = "WLAN SSID";
+static const char *password = "secret";
+
+// NTP parameters
+static const char *ntp_pool = "de.pool.ntp.org";
+static const char *cet_tz = "CET-1CEST,M3.5.0/02,M10.5.0/03";
+
+/** Global varibales */
+bool setup_completed = false;
+// used to alternate DC flow
+bool direction = false;
+// Keeps the number of flips to perform on the minute tile to adjust for DST changes.
+// Values can be positive, 0, or negativ.
+// It is assumed that the main loop is performed at a higher frequency than a minute (e.g. once every 500ms)
+// Positive values indicate the number of minutes to advance the clock.
+// A 0 indicates that the clock does not need to get changed.
+// Negative values indicate that the clock must be paused for -n minutes.
+// Positive values larger than one and negative values can be used to perform summer/winter time adjustment.
+int dst_adjustment = 0;
+// keeps the last time assumed to be displayed on clock
+struct tm clock_time;
+
+/**
+ * Setup NTP and set local time zone
+ */
+void initTime(String timezone)
+{
+  struct tm timeinfo;
+
+  DEBUG_PRINTLN("Setting up time");
+  // First connect to NTP server, with 0 TZ offset
+  configTime(0, 0, ntp_pool);
+  int ntp_retries = 3;
+  while (ntp_retries > 0)
+  {
+    if (!getLocalTime(&timeinfo))
+    {
+#ifdef DEBUG_ENABLED
+      Serial.println("  Failed to obtain time");
+      Serial.print("  Retry attempts left: ");
+      Serial.println(ntp_retries);
+#endif
+      ntp_retries -= 1;
+    }
+    else
+    {
+#ifdef DEBUG_ENABLED
+      Serial.println("  Got time from NTP");
+      Serial.printf("  Setting Timezone to %s\n", timezone.c_str());
+#endif
+      // Set the timezone
+      setenv("TZ", timezone.c_str(), 1);
+      tzset();
+      break;
+    }
+  }
+}
+
+// Function to alternate the direction of current to drive the clock motor
+void advanceMinuteTile()
+{
+  direction = !direction;
+#ifdef DEBUG_ENABLED
+  if (direction)
+  {
+    Serial.println("DC >>>");
+  }
+  else
+  {
+    Serial.println("DC <<<");
+  }
+#endif
+  digitalWrite(input1_pin, direction);
+  digitalWrite(input2_pin, !direction);
+  digitalWrite(enable_pin, HIGH); // Enable the motor
+}
+
+/**
+ * Setup Bodet Clock Driver
+ */
+// cppcheck-suppress unusedFunction
+void setup()
+{
+  Serial.begin(115200);
+  // Initializte the GPIO pins as output and set voltage
+  pinMode(enable_pin, OUTPUT);
+  pinMode(input1_pin, OUTPUT);
+  pinMode(input2_pin, OUTPUT);
+  //better without? advanceMinuteTile();
+  // just plugin in clock a few seconds after the minute switched to what is shown on the clock.
+
+#ifdef BARE_BONE_MODE
+  return;
+#endif
+
+  // Connect to WiFi network
+  WiFi.begin(ssid, password);
+  DEBUG_PRINT("Connecting to WiFi.");
+  while (WiFi.status() != WL_CONNECTED)
+  {
+    delay(200);
+    DEBUG_PRINT(".");
+  }
+  DEBUG_PRINTLN("");
+  DEBUG_PRINTLN("Connected to WiFi.");
+  DEBUG_PRINT("IP Address: ");
+  DEBUG_PRINTLN(WiFi.localIP());
+
+  // Configure NTP and clock time
+  initTime(cet_tz);
+  if (!getLocalTime(&clock_time))
+  {
+    DEBUG_PRINTLN("Failed to obtain clock time");
+    return;
+  }
+
+#ifdef DEBUG_ENABLED
+  Serial.print("Clock time is: ");
+  Serial.println(&clock_time, "%A, %B %d %Y %H:%M zone %Z %z ");
+  Serial.println("Setup completed.");
+#endif
+
+  setup_completed = true;
+}
+
+/**
+* Loop for bare bone testing mode.
+*/
+void bare_bone_loop()
+{
+  DEBUG_PRINT("Advance Tile in bare bone mode.");
+  advanceMinuteTile();
+  delay(500);
+}
+
+/**
+ * Main loop driving the minute tile flip. This loop should be run more often than once per minute.
+ * Otherwise the calcuation of minutes to flip will not work.
+ */
+void main_loop()
+{
+  // check if time advanced by a minute
+  bool advanced_by_minute = false;
+  struct tm system_time;
+  if (!getLocalTime(&system_time))
+  {
+    DEBUG_PRINTLN("Failed to obtain new system time. Using last clock time.");
+    system_time = clock_time;
+  }
+  if (system_time.tm_min != clock_time.tm_min)
+  {
+    advanced_by_minute = true;
+  }
+
+  // check for DST change
+  if (system_time.tm_isdst && !clock_time.tm_isdst)
+  {
+    // switch to summer time (DST / CEST)
+    dst_adjustment += 60;
+  }
+  else if (!system_time.tm_isdst && clock_time.tm_isdst)
+  {
+    // switch to winter time (non-DST / CET)
+    dst_adjustment -= 60;
+  }
+
+  // advance the clock per minute or to catch up after switch to DST
+  if (advanced_by_minute)
+  {
+#ifdef DEBUG_ENABLED
+    Serial.print("System time: ");
+    Serial.println(&system_time, "%A, %B %d %Y %H:%M:%S zone %Z %z ");
+    Serial.print("Clock time : ");
+    Serial.println(&clock_time, "%A, %B %d %Y %H:%M:%S zone %Z %z ");
+    Serial.print("Advance minute: ");
+    Serial.print(advanced_by_minute);
+    Serial.print("DST adjustments: ");
+    Serial.println(dst_adjustment);
+#endif
+    // set clock time to system time
+    clock_time = system_time;
+
+    if (dst_adjustment < 0)
+    {
+      // clock time is ahead of system time (DST to normal), do not flip minute tile.
+      dst_adjustment += 1;
+#ifdef DEBUG_ENABLED
+      Serial.print(" > DST adjustment: *not* advancing minute, left: ");
+      Serial.println(dst_adjustment);
+#endif
+    }
+    else
+    {
+      // clock time is in sync (normal) or behind system time, flip minute tile.
+      advanceMinuteTile();
+      // do not reduce dst_adjustment as this is a regular minute
+    }
+  }
+  else if (dst_adjustment > 0)
+  {
+    // if clock time is running behind (DST change), catch up
+    advanceMinuteTile();
+    dst_adjustment -= 1;
+#ifdef DEBUG_ENABLED
+    Serial.print(" > DST adjustment: advancing minute, delta left: ");
+    Serial.println(dst_adjustment);
+#endif
+  }
+
+  // 500ms delay is the result of tests with the clock.
+  // This results in tiles quickly for testing or during DST switch.
+  delay(500);
+}
+
+// cppcheck-suppress unusedFunction
+void loop()
+{
+  // To allow testing without WiFi and/or NTP
+  if (!setup_completed)
+  {
+    bare_bone_loop();
+    return;
+  }
+  else {
+    main_loop();
+  }  
+}