Initial commit

traffic-light-arduino.ino

+// Traffic light controller
+//  Date: 1/10/2019
+//  Author: Jakub Kolodziejski
+
+#define NS_GREEN 12
+#define NS_YELLOW 14
+#define NS_RED 15
+
+#define EW_GREEN 21
+#define EW_YELLOW 22
+#define EW_RED 23
+
+#define STATUS_LED 13
+
+// Built-in LED blink rate
+#define LED_BLINK_INTERVAL  1000
+unsigned long led_blink_next = 0;
+
+// Traffic light intervals
+unsigned long green_time = 10000;      // time (milliseconds) to stay green
+unsigned long yellow_time = 3000;      // time (milliseconds) to stay yellow
+unsigned long red_safety_time = 2000;  // time (milliseconds) to stay red in all directions for safety
+unsigned long traffic_light_next = red_safety_time;
+int state = 0;
+
+unsigned long t_start;
+unsigned long t_now;
+unsigned long t_status;
+unsigned long t_dot;
+
+bool auto_run = true;
+unsigned long uptime = 0;
+
+// Function to reset the Arduino
+void(* resetArduino) (void) = 0; //declare reset function @ address 0
+
+// the setup routine runs once when you press reset:
+void setup() {
+  // initialize the serial connection
+  Serial.begin(115200);
+
+  Serial.println(F("\n# Serial started"));
+  
+  // initialize the light contols pins as an output.
+  pinMode(LED_BUILTIN, OUTPUT);
+  pinMode(NS_RED, OUTPUT);
+  pinMode(NS_YELLOW, OUTPUT);  
+  pinMode(NS_GREEN, OUTPUT);
+  pinMode(EW_RED, OUTPUT);
+  pinMode(EW_YELLOW, OUTPUT);  
+  pinMode(EW_GREEN, OUTPUT);
+
+  // set all lights off
+  all_off();
+
+  // initialize time keeping
+  t_now = millis();
+  t_start = t_now;
+  t_status = t_now;
+  t_dot = t_now;
+
+  Serial.println(F("# Ready"));
+}
+
+// the loop routine runs over and over again forever:
+void loop() {
+//  // Prototype for fixed interval occurence
+//  if (millis() >= foo_next or force_update) {
+//    foo_next += FOO_INTERVAL;
+//    // do stuff
+//  }
+
+  // Prototype for fixed interval occurence
+  if (auto_run && millis() >= traffic_light_next) {
+    state = (state < 6) ? state + 1 : 1;    // increment state or loop back to state 1 
+    set_state();
+  }
+
+  // Blink the built-in LED at a fixed rate only to indicate the code is running
+  if (millis() >= led_blink_next) {
+    led_blink_next += LED_BLINK_INTERVAL;
+    toggle(LED_BUILTIN);
+//    Serial.print(F("state: "));
+//    Serial.println(state);
+  }
+
+  // do stuff only when you receive data:
+  if (Serial.available() > 0) {
+    // read the incoming byte:
+    int incomingByte = Serial.read();
+    switch (incomingByte) {
+      case '?':
+        help();
+        break;
+      case 'r':
+        resetArduino();
+        break;
+      case 'a':
+        Serial.println(F("# Auto-run enabled"));
+        auto_run = true;
+        traffic_light_next = millis();
+        break;
+      case '1':
+      case '2':
+      case '3':
+      case '4':
+      case '5':
+      case '6':
+        auto_run = false;
+        state = incomingByte - 48;    // -48 converts the ASCII to the proper integer
+        set_state();
+        break;
+      default:
+        Serial.println(F("# Unrecognized command"));
+        break;
+    }
+  }
+}
+
+void help() {
+  Serial.println(F("# Command List"));
+  Serial.println(F("# ? - Print this help screen"));
+  Serial.println(F("# r - Reset the Arduino"));
+  Serial.println(F("# a - Run lights automatically"));
+  Serial.println(F("# 1 - State 1: NS red, EW red (safety delay)"));
+  Serial.println(F("# 2 - State 2: NS green, EW red"));
+  Serial.println(F("# 3 - State 3: NS yellow, EW red"));
+  Serial.println(F("# 4 - State 4: NS red, EW red (safety delay)"));
+  Serial.println(F("# 5 - State 5: NS red, EW green"));
+  Serial.println(F("# 6 - State 6: NS red, EW yellow"));
+}
+
+void all_off() {
+  digitalWrite(NS_RED, LOW);
+  digitalWrite(NS_YELLOW, LOW);
+  digitalWrite(NS_GREEN, LOW);
+  digitalWrite(EW_RED, LOW);
+  digitalWrite(EW_YELLOW, LOW);
+  digitalWrite(EW_GREEN, LOW);
+}
+
+void on(int pin) {
+  digitalWrite(pin, HIGH);
+}
+
+void toggle(int pin) {
+  digitalWrite(pin, !digitalRead(pin));
+}
+
+void set_state() {
+  switch (state) {
+    case 1:
+      Serial.println(F("# State 1: NS red, EW red (safety delay)"));
+      traffic_light_next += red_safety_time;
+      all_off();
+      on(NS_RED);
+      on(EW_RED);
+      break;
+    case 2:
+      Serial.println(F("# State 2: NS green, EW red"));
+      traffic_light_next += green_time;
+      all_off();
+      on(NS_GREEN);
+      on(EW_RED);
+      break;
+    case 3:
+      Serial.println(F("# State 3: NS yellow, EW red"));
+      traffic_light_next += yellow_time;
+      all_off();
+      on(NS_YELLOW);
+      on(EW_RED);
+      break;
+    case 4:
+      Serial.println(F("# State 4: NS red, EW red (safety delay)"));
+      traffic_light_next += red_safety_time;
+      all_off();
+      on(NS_RED);
+      on(EW_RED);
+      break;
+    case 5:
+      Serial.println(F("# State 5: NS red, EW green"));
+      traffic_light_next += green_time;
+      all_off();
+      on(NS_RED);
+      on(EW_GREEN);
+      break;
+    case 6:
+      Serial.println(F("# State 6: NS red, EW yellow"));
+      traffic_light_next += yellow_time;
+      all_off();
+      on(NS_RED);
+      on(EW_YELLOW);
+      break;
+  }
+}