Files
modbusmaster/pyserialext/writec.c

27 lines
468 B
C

#include <unistd.h>
#include <sys/ioctl.h>
#include <stdint.h>
#include <wiringPi.h>
const uint8_t DE_PIN = 0;
int init() {
wiringPiSetup();
pinMode(DE_PIN, OUTPUT);
digitalWrite(DE_PIN, LOW);
}
ssize_t writec(int fd, char *buf, size_t count) {
digitalWrite(DE_PIN, HIGH);
ssize_t r = write(fd, buf, count);
uint8_t lsr;
do {
int r = ioctl(fd, TIOCSERGETLSR, &lsr);
} while (!(lsr & TIOCSER_TEMT));
digitalWrite(DE_PIN, LOW);
return r;
}