Fixed a bug of the pedestrain traffic timer where it would restart from

5 to 1 again and Added comments for the whole project and added timers
as a member of the Traffic struct to add more generlization of the

1 files changed, 78 insertions, 43 deletions

diff --git a/trafficlight.c b/trafficlight.c
index c46ae48..969ffae 100644
--- a/trafficlight.c
+++ b/trafficlight.c
@@ -1,5 +1,8 @@
 #include "trafficlight.h"
 
+/* 
+  Function to handle the state machine of each traffic light
+*/
 void set_tf_color(Traffic tf, uint8_t color) {
   uint32_t pins = 0xFF;
 	switch (color) {
@@ -15,6 +18,9 @@ void set_tf_color(Traffic tf, uint8_t color) {
 	}
 }
 
+/* 
+  Function that takes port base address and the clk of the port and the corresponding input and output pins
+*/
 void PortInit(uint32_t port, uint32_t clk, uint32_t input, uint32_t output) {
   uint32_t pins = 0xFF; 
   SysCtlPeripheralEnable(clk);
@@ -26,6 +32,18 @@ void PortInit(uint32_t port, uint32_t clk, uint32_t input, uint32_t output) {
   GPIO_STRENGTH_2MA,GPIO_PIN_TYPE_STD_WPU);
 }
 
+void portsInit() {
+  PortInit(GPIO_PORTA_BASE, SYSCTL_PERIPH_GPIOA, 0x0, 0xFF); // Initialize porta as all output
+  PortInit(GPIO_PORTB_BASE, SYSCTL_PERIPH_GPIOB, 0x0, 0xFF); // Initialize portb as all output
+  PortInit(GPIO_PORTD_BASE, SYSCTL_PERIPH_GPIOD, 0x0, 0xFF); // Initialize portb as all output
+  PortInit(GPIO_PORTE_BASE, SYSCTL_PERIPH_GPIOE, 0x0, 0xFF); // Initialize portb as all output
+  PortInit(GPIO_PORTF_BASE, SYSCTL_PERIPH_GPIOF, 0x1, 0x7E); // Initialize portf as the first pin input and the rest output
+}
+
+/*
+  Function that takes a timer address and the function that handler the timer interrupt flag, 
+  the clock of the timer and the intial delay of the timer
+*/
 void TimerInit(uint32_t timer, void(*timer_handler)(), uint32_t clk, uint32_t delay) {
   SysCtlPeripheralEnable(clk);
   while(!SysCtlPeripheralReady(clk)) {}
@@ -38,35 +56,45 @@ void TimerInit(uint32_t timer, void(*timer_handler)(), uint32_t clk, uint32_t de
   TimerIntEnable(timer, TIMER_TIMA_TIMEOUT | TIMER_TIMB_TIMEOUT);
 }
 
+/*
+  Function that handles traffic_1 timer 
+*/
 void Timer0_Handler() {
-  Traffic_Handler(&tf1, TIMER0_BASE);
+  Traffic_Handler(&tf1);
 }
 
+/*
+  Function that handles traffic_2 timer
+*/
 void Timer1_Handler() {
-  Traffic_Handler(&tf2, TIMER1_BASE);
+  Traffic_Handler(&tf2);
 }
 
+/*
+  Function that handles pedestrian traffic timer
+*/
 void Timer2_Handler() {
-  TimerIntClear(TIMER2_BASE, TIMER_BOTH);
+  TimerIntClear(tf_ped.timer, TIMER_BOTH);
   switch(tf_ped.cur_color) {
-    case RED: 
+    case RED: // If I am here it means I finished my red period
       tf_ped.cur_color = GREEN;
       set_tf_color(tf_ped, GREEN);
-      TimerLoadSet(TIMER2_BASE, TIMER_BOTH, GREEN_PERIOD);
+      TimerLoadSet(tf_ped.timer, TIMER_BOTH, GREEN_PERIOD);
       break;
-    case YELLOW: 
+    case YELLOW: // If I am here it means I finished my yellow period
+      // set both traffic1 and traffic2 to their previous color before the pedestrian pushed the button
       set_tf_color(tf1, tf1.cur_color);
       set_tf_color(tf2, tf2.cur_color);
       set_tf_color(tf_ped, RED);
-      TimerEnable(TIMER0_BASE, TIMER_BOTH);
-      TimerEnable(TIMER1_BASE, TIMER_BOTH);
-      // TimerDisable(TIMER2_BASE, TIMER_BOTH);
+      // Re enable traffic1 and 2 timers
+      TimerEnable(tf1.timer, TIMER_BOTH);
+      TimerEnable(tf2.timer, TIMER_BOTH);
       switch_pressed = false;
       break;
-    case GREEN: 
+    case GREEN: // If I am here it means I finished my green period
       tf_ped.cur_color = YELLOW;
       set_tf_color(tf_ped, YELLOW);
-      TimerLoadSet(TIMER2_BASE, TIMER_BOTH, YELLOW_PERIOD);
+      TimerLoadSet(tf_ped.timer, TIMER_BOTH, YELLOW_PERIOD);
       break;
   }
 }
@@ -74,74 +102,83 @@ void Timer2_Handler() {
 void Switch_Handler() {
   GPIOIntClear(GPIO_PORTF_BASE, GPIO_PIN_0);
   switch_pressed = true;
-  TimerDisable(TIMER0_BASE, TIMER_BOTH);
-  TimerDisable(TIMER1_BASE, TIMER_BOTH);
+  // Disable the timers of both tf1 and tf2
+  TimerDisable(tf1.timer, TIMER_BOTH);
+  TimerDisable(tf2.timer, TIMER_BOTH);
+  // set both traffic light to red
   set_tf_color(tf1, RED);
   set_tf_color(tf2, RED);
+  // set pedestrian traffic light to green
   set_tf_color(tf_ped, GREEN);
   tf_ped.cur_color = RED; 
-  TimerInit(TIMER2_BASE, Timer2_Handler, SYSCTL_PERIPH_TIMER2, period_3); // Intialize Timer2 with period_3
+  TimerInit(tf_ped.timer, Timer2_Handler, SYSCTL_PERIPH_TIMER2, period_3); // Intialize Timer2 with period_3
 }
 
 void TrafficInit() {
-  PortInit(GPIO_PORTF_BASE, SYSCTL_PERIPH_GPIOF, 0x1, 0x7E); // Initialize portf
-  PortInit(GPIO_PORTA_BASE, SYSCTL_PERIPH_GPIOA, 0x0, 0xFF); // Initialize porta
-  PortInit(GPIO_PORTB_BASE, SYSCTL_PERIPH_GPIOB, 0x0, 0xFF); // Initialize portb
-  PortInit(GPIO_PORTE_BASE, SYSCTL_PERIPH_GPIOE, 0x0, 0xFF); // Initialize portb
-  PortInit(GPIO_PORTD_BASE, SYSCTL_PERIPH_GPIOD, 0x0, 0xFF); // Initialize portb
+  portsInit(); // Used ports intialization
   __asm("CPSID I"); // Disable all interrupts
-  GPIOIntUnregister(GPIO_PORTF_BASE);
-  GPIOIntRegister(GPIO_PORTF_BASE, Switch_Handler);
-  GPIOIntEnable(GPIO_PORTF_BASE, GPIO_INT_PIN_0);
-	GPIOIntTypeSet(GPIO_PORTF_BASE, GPIO_PIN_0, GPIO_RISING_EDGE);
-	IntEnable(INT_GPIOF_TM4C123);
+  GPIOIntUnregister(GPIO_PORTF_BASE); // unregister interrupts for portf as a precaution
+  GPIOIntRegister(GPIO_PORTF_BASE, Switch_Handler); // Set Switch_handler as the interrupt handler for portf
+  GPIOIntEnable(GPIO_PORTF_BASE, GPIO_INT_PIN_0); // Enable interrupts for pin0 of portf
+	GPIOIntTypeSet(GPIO_PORTF_BASE, GPIO_PIN_0, GPIO_RISING_EDGE); // Make interrupts happen with rising edge
+	IntEnable(INT_GPIOF_TM4C123); // Enable CPU interrupts
   IntMasterEnable();
-  TimerInit(TIMER0_BASE, Timer0_Handler, SYSCTL_PERIPH_TIMER0, period_1); // Intialize Timer0 with period_1
-  TimerInit(TIMER1_BASE, Timer1_Handler, SYSCTL_PERIPH_TIMER1, period_2); // Intialize Timer1 with period_2
+  TimerInit(tf1.timer, Timer0_Handler, SYSCTL_PERIPH_TIMER0, period_1); // Intialize Timer0 with period_1
+  TimerInit(tf2.timer, Timer1_Handler, SYSCTL_PERIPH_TIMER1, period_2); // Intialize Timer1 with period_2
   __asm("CPSIE I"); // Enable all interrupts
   while(1) {
-    BcdWrite(bcd1, TIMER0_BASE, false);
-    BcdWrite(bcd2, TIMER1_BASE, false);
     if(switch_pressed) {
-      BcdWrite(bcd_ped, TIMER2_BASE, true);
-    } 
+      BcdWrite(bcd_ped, tf_ped.timer, true);
+    } else {
+      BcdWrite(bcd1, tf1.timer, false);
+      BcdWrite(bcd2, tf2.timer, false);
+    }
   }
 }
 
-void Traffic_Handler(Traffic *tf, uint32_t timer) {
-  TimerIntClear(timer, TIMER_BOTH);
+/*
+  Function that handles the timers of each traffic light
+*/
+void Traffic_Handler(Traffic *tf) {
+  TimerIntClear(tf->timer, TIMER_BOTH);
   if(switch_pressed) {
     set_tf_color(*tf, RED);
   } else {
     switch(tf->cur_color) {
-      case RED: 
+      case RED: // If I am here it means I finished my red period
         tf->cur_color = GREEN;
         set_tf_color(*tf, GREEN);
-        TimerLoadSet(timer, TIMER_BOTH, GREEN_PERIOD);
+        TimerLoadSet(tf->timer, TIMER_BOTH, GREEN_PERIOD);
         break;
-      case YELLOW: 
+      case YELLOW: // If I am here it means I finished my yellow period
         tf->cur_color = RED;
         set_tf_color(*tf, RED);
-        TimerLoadSet(timer, TIMER_BOTH, RED_PERIOD);
+        TimerLoadSet(tf->timer, TIMER_BOTH, RED_PERIOD);
         break;
-      case GREEN: 
+      case GREEN: // If I am here it means I finished my green period
         tf->cur_color = YELLOW;
         set_tf_color(*tf, YELLOW);
-        TimerLoadSet(timer, TIMER_BOTH, YELLOW_PERIOD);
+        TimerLoadSet(tf->timer, TIMER_BOTH, YELLOW_PERIOD);
         break;
     }
   }
 }
 
+/*
+  A function that takes a bcd(decoder) and a timer and flag ped which states if the bcd is a pedestrian bcd or not,
+  and the function writes the current value of the timer in the right pins of the right port
+*/
 void BcdWrite(Bcd bcd, uint32_t timer, bool ped) {
-  uint8_t n = (TimerValueGet(timer, TIMER_A) / TIVA_CLK) + 1;
-  int bin[4];
+  // n is the current value of the timer, we add one because we don't want 0 indexing
+  uint8_t n = (TimerValueGet(timer, TIMER_A) / TIVA_CLK) + 1; 
+  int bin[4]; // An array that will contain the binary representation of the current value of the timer in seconds
+  // treat pedestrian as a special case because it contains pins in two different ports 3 in A and 1 in E
   if(ped) {
+    // loop to get the binary representation of current timer
     for(int i = 0; i < 4; i++) {
       bin[i] = n % 2;
       n /= 2;
     }
-    // GPIOPinWrite(GPIO_PORTA_BASE, 0xFF, (((bin[1]) << bcd.B) | ((bin[2]) << bcd.C)));
     DIO_WritePin(&GPIO_PORTA_DATA_R, bcd.A, bin[0]);
     DIO_WritePin(&GPIO_PORTA_DATA_R, bcd.B, bin[1]);
     DIO_WritePin(&GPIO_PORTA_DATA_R, bcd.C, bin[2]);
@@ -153,7 +190,5 @@ void BcdWrite(Bcd bcd, uint32_t timer, bool ped) {
       n /= 2;
     }
     GPIOPinWrite(bcd.port, 0xFF, ((bin[0]) << bcd.A) | ((bin[1]) << bcd.B) | (bin[2] << bcd.C) | (bin[3] << bcd.D));
-    // GPIOPinWrite(bcd.port, 0xFF, (1 << bcd.pins[i]));
-
   }
 }