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#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) {
case RED:
GPIOPinWrite(tf.port, pins, (1 << tf.red));
break;
case YELLOW:
GPIOPinWrite(tf.port ,pins, (1 << tf.yellow));
break;
case GREEN:
GPIOPinWrite(tf.port ,pins, (1 << tf.green));
break;
}
}
/*
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);
while(!SysCtlPeripheralReady(clk)) {};
GPIOUnlockPin(port, pins);
GPIOPinTypeGPIOInput(port, input);
GPIOPinTypeGPIOOutput(port, output);
GPIOPadConfigSet (port, pins,
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)) {}
TimerDisable(timer, TIMER_BOTH);
TimerConfigure(timer, (TIMER_CFG_PERIODIC));
TimerLoadSet(timer, TIMER_BOTH, delay);
TimerIntUnregister(timer, TIMER_BOTH);
TimerEnable(timer, TIMER_BOTH);
TimerIntRegister(timer, TIMER_BOTH, timer_handler);
TimerIntEnable(timer, TIMER_TIMA_TIMEOUT | TIMER_TIMB_TIMEOUT);
}
/*
Function that handles traffic_1 timer
*/
void Timer0_Handler() {
Traffic_Handler(&tf1);
}
/*
Function that handles traffic_2 timer
*/
void Timer1_Handler() {
Traffic_Handler(&tf2);
}
/*
Function that handles pedestrian traffic timer
*/
void Timer2_Handler() {
TimerIntClear(tf_ped.timer, TIMER_BOTH);
switch(tf_ped.cur_color) {
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(tf_ped.timer, TIMER_BOTH, GREEN_PERIOD);
break;
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);
// Re enable traffic1 and 2 timers
TimerEnable(tf1.timer, TIMER_BOTH);
TimerEnable(tf2.timer, TIMER_BOTH);
switch_pressed = false;
break;
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(tf_ped.timer, TIMER_BOTH, YELLOW_PERIOD);
break;
}
}
void Switch_Handler() {
GPIOIntClear(GPIO_PORTF_BASE, GPIO_PIN_0);
switch_pressed = true;
// 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(tf_ped.timer, Timer2_Handler, SYSCTL_PERIPH_TIMER2, period_3); // Intialize Timer2 with period_3
}
void TrafficInit() {
portsInit(); // Used ports intialization
__asm("CPSID I"); // Disable all interrupts
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
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
IntMasterEnable();
__asm("CPSIE I"); // Enable all interrupts
while(1) {
if(switch_pressed) {
BcdWrite(bcd_ped, tf_ped.timer, true);
} else {
BcdWrite(bcd1, tf1.timer, false);
BcdWrite(bcd2, tf2.timer, false);
}
}
}
/*
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: // If I am here it means I finished my red period
tf->cur_color = GREEN;
set_tf_color(*tf, GREEN);
TimerLoadSet(tf->timer, TIMER_BOTH, GREEN_PERIOD);
break;
case YELLOW: // If I am here it means I finished my yellow period
tf->cur_color = RED;
set_tf_color(*tf, RED);
TimerLoadSet(tf->timer, TIMER_BOTH, RED_PERIOD);
break;
case GREEN: // If I am here it means I finished my green period
tf->cur_color = YELLOW;
set_tf_color(*tf, YELLOW);
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) {
// 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;
}
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]);
DIO_WritePin(&GPIO_PORTE_DATA_R, bcd.D, bin[3]);
}
else {
for(int i = 0; i < 4; i++) {
bin[i] = n % 2;
n /= 2;
}
GPIOPinWrite(bcd.port, 0xFF, ((bin[0]) << bcd.A) | ((bin[1]) << bcd.B) | (bin[2] << bcd.C) | (bin[3] << bcd.D));
}
}
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