57 lines
1 KiB
C
57 lines
1 KiB
C
#include "LPC17xx.h"
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unsigned long int duty_cycle = 0;
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int direction = 1;
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int step = 50;
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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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if (direction == 1)
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{
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duty_cycle += step;
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if (duty_cycle >= 3000)
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{
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duty_cycle = 3000;
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direction = 0;
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}
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}
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else
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{
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duty_cycle -= step;
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if (duty_cycle <= 0)
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{
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duty_cycle = 0;
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direction = 1;
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}
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}
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LPC_PWM1->MR4 = duty_cycle;
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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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LPC_PINCON->PINSEL3 |= (2 << 14);
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LPC_PWM1->TCR = (1 << 1);
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LPC_PWM1->CTCR = 0;
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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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while (1);
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}
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