32 lines
590 B
C
32 lines
590 B
C
#include <unistd.h>
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#include <termios.h>
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#include <sys/ioctl.h>
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#include <stdio.h>
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#include <linux/serial.h>
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#include <errno.h>
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#include <string.h>
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#include <stdint.h>
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#include <wiringPi.h>
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const uint8_t DE_PIN = 0;
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int set_rs485_mode(int fd) {
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wiringPiSetup();
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pinMode(DE_PIN, OUTPUT);
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digitalWrite(DE_PIN, HIGH);
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}
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ssize_t writec(int fd, char *buf, size_t count) {
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digitalWrite(DE_PIN, LOW);
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ssize_t r = write(fd, buf, count);
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uint8_t lsr;
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do {
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int r = ioctl(fd, TIOCSERGETLSR, &lsr);
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} while (!(lsr & TIOCSER_TEMT));
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digitalWrite(DE_PIN, HIGH);
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return r;
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}
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