135 lines
2.6 KiB
C
135 lines
2.6 KiB
C
/*
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main.c
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raspberry pi zero GPIO read test
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For speedup run this example as root, either wis
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sudo ./main
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or by setting the superuser bit:
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sudo chown root:root ./main
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sudo chmod u+s ./main
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <signal.h>
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#include "bcm2835.h"
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#include "raspi_gpio_hal.h"
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void sigtermhandler(int x)
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{
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puts("SIGTERM");
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bcm2835_close();
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exit(0);
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}
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void siginthandler(int x)
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{
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puts("SIGINT");
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bcm2835_close();
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exit(0);
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}
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#define BUTTON_STATE_NOT_PRESSED 0
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#define BUTTON_STATE_HIGH_DETECT 1
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#define BUTTON_STATE_HIGH_WAIT 2
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#define BUTTON_STATE_LOW_DELAY 3
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struct button_struct
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{
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int state;
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int delay;
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uint8_t pin;
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};
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typedef struct button_struct button_t;
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#define BUTTON_DELAY_HIGH 2
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#define BUTTON_DELAY_LOW 2
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#define BUTTON_CNT 2
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button_t button_list[BUTTON_CNT];
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int button_init(void)
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{
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int i;
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for( i = 0; i < BUTTON_CNT; i++ )
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{
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bcm2835_gpio_fsel(button_list[i].pin, BCM2835_GPIO_FSEL_INPT);
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}
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}
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int button_get_event(void)
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{
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int button_value = -1;
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int i;
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for( i = 0; i < BUTTON_CNT; i++ )
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{
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switch(button_list[i].state)
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{
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case BUTTON_STATE_NOT_PRESSED:
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button_list[i].delay = 0;
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if ( bcm2835_gpio_lev(button_list[i].pin) != 0 )
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button_list[i].state = BUTTON_STATE_HIGH_DETECT;
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break;
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case BUTTON_STATE_HIGH_DETECT:
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if ( bcm2835_gpio_lev(button_list[i].pin) == 0 )
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{
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button_list[i].delay = 0;
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button_list[i].state = BUTTON_STATE_LOW_DELAY;
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}
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button_list[i].delay++;
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if ( button_list[i].delay >= BUTTON_DELAY_HIGH )
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{
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button_value = i;
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button_list[i].state = BUTTON_STATE_HIGH_WAIT;
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}
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break;
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case BUTTON_STATE_HIGH_WAIT:
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if ( bcm2835_gpio_lev(button_list[i].pin) == 0 )
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{
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button_list[i].delay = 0;
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button_list[i].state = BUTTON_STATE_LOW_DELAY;
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}
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break;
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case BUTTON_STATE_LOW_DELAY:
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button_list[i].delay++;
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if ( button_list[i].delay >= BUTTON_DELAY_LOW )
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button_list[i].state = BUTTON_STATE_NOT_PRESSED;
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break;
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}
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}
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return button_value;
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}
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int main(void)
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{
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int i = 0;
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int b = -1;
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int pins[4] = { 12, 13, 16, 17 };
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if (!bcm2835_init())
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exit(1);
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signal(SIGTERM, sigtermhandler);
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signal(SIGINT, siginthandler);
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atexit((void (*) (void))bcm2835_close);
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button_list[0].pin = 12;
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button_list[1].pin = 16;
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button_init();
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for( ;; )
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{
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b = button_get_event();
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if ( b >= 0 )
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printf("Button %d\n", b);
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}
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//delaynanoseconds(500000000UL);
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} |