70 lines
1.4 KiB
C
70 lines
1.4 KiB
C
#include "LPC17xx.h"
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#include <stdio.h>
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unsigned long int duty_cycle = 0;
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unsigned long int new_duty = 0;
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int press_count = 0;
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void delayMs(unsigned int ms)
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{
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unsigned int i, j;
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for (i = 0; i < ms; i++)
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for (j = 0; j < 20000; j++);
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}
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void PWM1_IRQHandler(void)
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{
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if (LPC_PWM1->IR & (1 << 0))
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{
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LPC_PWM1->MR4 = new_duty;
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LPC_PWM1->LER = (1 << 4);
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LPC_PWM1->IR = (1 << 0);
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}
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}
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int main(void)
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{
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char key;
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LPC_PINCON->PINSEL3 |= (2 << 14);
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LPC_PWM1->TCR = (1 << 1);
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LPC_PWM1->CTCR = 0x00;
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LPC_PWM1->PR = 0;
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LPC_PWM1->MR0 = 3000;
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LPC_PWM1->MR4 = duty_cycle;
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LPC_PWM1->MCR = (1 << 1) | (1 << 0);
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LPC_PWM1->PCR = (1 << 12);
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LPC_PWM1->LER = (1 << 0) | (1 << 4);
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NVIC_EnableIRQ(PWM1_IRQn);
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LPC_PWM1->TCR = (1 << 0) | (1 << 3);
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printf("Press any key to change brightness...\n");
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while (1)
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{
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key = getchar();
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if (key)
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{
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press_count++;
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if (press_count == 1)
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new_duty = 300;
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else if (press_count == 2)
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new_duty = 1500;
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else if (press_count == 3)
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new_duty = 2700;
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else
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{
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new_duty = 0;
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press_count = 0;
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}
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printf("Duty cycle set to %lu\r\n", new_duty);
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delayMs(500);
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}
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}
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}
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