116 lines
4.6 KiB
C
116 lines
4.6 KiB
C
#include <stdint.h>
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#include <stdbool.h>
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#include "tm4c123gh6pm.h"
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// Global Variables
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volatile int duty = 50; // Initial duty cycle
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volatile bool buttonPressed = false; // Button state
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volatile uint32_t pressDuration = 0; // Track how long the button is pressed
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const long int PWM_PERIOD = 1000; // Period for 100kHz in microseconds (10ms)
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#define STCTRL *((volatile uint32_t *) 0xE000E010) // Control and status
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#define STRELOAD *((volatile uint32_t *) 0xE000E014) // Reload value
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#define STCURRENT *((volatile uint32_t *) 0xE000E018) // Current value
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#define COUNT_FLAG (1 << 16) // Bit 16 of CSR automatically set to 1
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#define ENABLE (1 << 0) // Bit 0 of CSR to enable the timer
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#define CLKINT (1 << 2) // Bit 2 of CSR to specify CPU clock
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#define CLOCK_HZ 16000000 // Clock frequency
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#define INTEN (1 << 1) // Bit 1 of CSR to enable interrupt
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#define SYSTICK_RELOAD_VALUE(us) ((CLOCK_HZ / 1000000) * (us) - 1) // value in microseconds
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void GPIO_PORT_F_init(void) {
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SYSCTL_RCGC2_R |= 0x00000020; // Enable clock to GPIOF
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GPIO_PORTF_LOCK_R = 0x4C4F434B; // Unlock commit register
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GPIO_PORTF_CR_R = 0x1F; // Make PORTF0 configurable
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GPIO_PORTF_DEN_R = 0x1F; // Set PORTF digital enable
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GPIO_PORTF_DIR_R = 0x0E; // Set PF0, PF4 as input and PF1, PF2, PF3 as output
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GPIO_PORTF_PUR_R = 0x11; // PORTF PF0 and PF4 is pulled up
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NVIC_EN0_R |= 1 << 30; // Enable interrupt for PORTF
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GPIO_PORTF_IS_R = 0x00; // Make it edge-sensitive
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GPIO_PORTF_IBE_R = 0x00; // Trigger on one edge
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GPIO_PORTF_IEV_R = 0x00; // Falling edge event
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GPIO_PORTF_IM_R |= 0x11; // Unmask interrupts for switch 1 and Switch 2
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}
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void systick_setting(void) {
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STRELOAD = SYSTICK_RELOAD_VALUE(PWM_PERIOD/100); // Set reload value for 10 µs intervals (100 kHz)
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STCTRL |= (CLKINT | ENABLE | INTEN); // Set internal clock, enable the timer
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STCURRENT = 0; // Clear STCURRENT value
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}
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void delay(int us) // DEFINING DELAY FUNCTION
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{
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STRELOAD = SYSTICK_RELOAD_VALUE(us); // RELOAD VALUE FOR REQUIRED DELAY
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STCURRENT = 0; // Clear STCURRENT
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STCTRL |= (1 << 0) | (1 << 2); // Enable SysTick
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while ((STCTRL & (1 << 16)) == 0); // Wait until flag is set
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STCTRL &= 0x0; // Stop the timer
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}
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void SystickHandler(void)
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{ // SysTick interrupt handler
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static int ontime = 0;
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ontime++;
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if (ontime < duty)
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{
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GPIO_PORTF_DATA_R |= 0x02; // LED ON
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}
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else
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{
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GPIO_PORTF_DATA_R &= ~0x02; // LED OFF
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}
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if (ontime >= 100)
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{
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ontime = 0; // Reset counter after one period
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}
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if (buttonPressed) //Press Duration Measurement
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{
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pressDuration++;
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}
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}
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void GPIOF_interruptHandler(void) {
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// Check if PF0 (SW1) is pressed (interrupt)
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//long int i = 0;
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//for (i=0; i < 100000 ; i++){ }
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if (!(GPIO_PORTF_DATA_R & 0x01))
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{
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if (!buttonPressed) // If button was not pressed
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{
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buttonPressed = true;
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pressDuration = 0; // Reset press duration
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}
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} else { // Button released
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if (buttonPressed) { // Only if button was previously pressed
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buttonPressed = false;
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// Determine press duration
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if (pressDuration > 100)
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{ // Long press (>1 sec if using 10 ms ticks)
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duty -= 5; // Decrease duty cycle
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if (duty < 0)
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{duty = 0;
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}
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} else if (pressDuration < 100){ // Short press
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duty += 5; // decrease duty cycle
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if (duty > 100)
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{duty = 100;
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}
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}
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}
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GPIO_PORTF_ICR_R = 0x01; // Clear interrupt flag
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}
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}
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int main(void) {
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GPIO_PORT_F_init(); // GPIO initialization function
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systick_setting(); // SysTick setup
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while (1) {
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// Main loop does nothing; everything is handled in interrupts
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}
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}
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