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How set certain time for digitalwrite
Posted: Mon Nov 02, 2015 4:48 am
by girl71
I'm new in programming with wiring pi
and I want to set time for digital write with get time(NULL) after get key then stop writing (after certain time or with e key)and goto first of loop , my program doesn't work ,what is the problem??
I try with millis() but after 5sec val doesn't change auto to LOW until I press d or a val be LOW and goto first of the loop,Could this be another solution?
Code: Select all
void digital::loop(int motor_pin_1, int motor_pin_2, char key) {
time_t now,after;
time_t second=10;
printf("press 'd (<--open-->)' or 'a (-->close<--)' key OR 'e' to stop and change mode:\n");
do {
key = getchar();
now = time(NULL);
after= now+ second;
if (key == 'd') {
printf("<--open-->\n");
digitalWrite(motor_pin_1, HIGH);
digitalWrite(motor_pin_2, LOW);
}
else if (key == 'a') {
printf("-->close<--\n");
digitalWrite(motor_pin_2, HIGH);
digitalWrite(motor_pin_1, LOW);
//delayMicroseconds(200);
// digitalWrite(motor_pin_1, LOW);
// digitalWrite(motor_pin_2, LOW);
}
} while (key != 'e' || now<after);
}
Code: Select all
void digital::loop(int motor_pin_1, int motor_pin_2, char key) {
unsigned long startTime;
printf("press 'd (<--open-->)' or 'a (-->close<--)' key OR 'e' to stop and change mode:\n");
do{
key = getchar();
startTime = millis();
if (key == 'd') {
printf("<--open-->\n");
digitalWrite(motor_pin_1, HIGH);
digitalWrite(motor_pin_2, LOW);
}
else if (key == 'a') {
printf("-->close<--\n");
digitalWrite(motor_pin_2, HIGH);
digitalWrite(motor_pin_1, LOW);
}
else if (key == 'e') {
break;
}
}while (millis() - startTime <= 5000);
Re: How set certain time for digitalwrite
Posted: Mon Nov 02, 2015 11:45 am
by joan
The getchar function blocks until a carriage return is pressed.
Re: How set certain time for digitalwrite
Posted: Mon Nov 02, 2015 5:10 pm
by girl71
scanf, is the same does??
Re: How set certain time for digitalwrite
Posted: Mon Nov 02, 2015 5:20 pm
by joan
girl71 wrote:scanf, is the same does??
Yes, scanf does the same.
You will need to do raw IO. See the following example.
Call the file term.c
gcc term.c
./a.out
Press esc to finish.
Code: Select all
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/select.h>
#include <termios.h>
struct termios orig_termios;
void reset_terminal_mode()
{
tcsetattr(0, TCSANOW, &orig_termios);
}
void set_conio_terminal_mode()
{
struct termios new_termios;
/* take two copies - one for now, one for later */
tcgetattr(0, &orig_termios);
memcpy(&new_termios, &orig_termios, sizeof(new_termios));
/* register cleanup handler, and set the new terminal mode */
atexit(reset_terminal_mode);
cfmakeraw(&new_termios);
tcsetattr(0, TCSANOW, &new_termios);
}
int dataRdy(int fd)
{
struct timeval tv = { 0L, 0L };
fd_set fds;
FD_ZERO(&fds);
FD_SET(fd, &fds);
return select(fd+1, &fds, NULL, NULL, &tv);
}
int getch()
{
int r;
unsigned char c;
if ((r = read(0, &c, sizeof(c))) < 0)
{
return r;
}
else
{
return c;
}
}
int main(int argc, char *argv[])
{
int c;
set_conio_terminal_mode();
while(1)
{
if (dataRdy(0))
{
c = getch();
printf("%c (%d)\n", c, c);
if (c == 27) break; /* esc key */
}
usleep(1000);
}
reset_terminal_mode();
}
Re: How set certain time for digitalwrite
Posted: Mon Nov 02, 2015 7:38 pm
by girl71
your mean change 'd' to '100' of ascii value??If i change it the problem still exist
Re: How set certain time for digitalwrite
Posted: Mon Nov 02, 2015 9:13 pm
by joan
girl71 wrote:your mean change 'd' to '100' of ascii value??If i change it the problem still exist
No. I mean that you can not use getchar or scanf to do what you want. You must use non-blocking I/O as in the example I gave.
Re: How set certain time for digitalwrite
Posted: Tue Nov 03, 2015 5:59 am
by girl71
Thank you but,If I use part of your code, for stop program still need press key.......
Code: Select all
int digital:: getch()
{
int r;
unsigned char c;
if ((r = read(0, &c, sizeof(c))) < 0)
{
return r;
}
else
{
return c;
}
}
void digital::loop(int motor_pin_1, int motor_pin_2, char key) {
unsigned long startTime;
printf("press 'd (<--open-->)' or 'a (-->close<--)' key OR 'e' to stop and change mode:\n");
do{
key = getch();
startTime = millis();
if (key == 'd') {
printf("<--open-->\n");
digitalWrite(motor_pin_1, HIGH);
digitalWrite(motor_pin_2, LOW);
}
else if (key == 'a') {
printf("-->close<--\n");
digitalWrite(motor_pin_2, HIGH);
digitalWrite(motor_pin_1, LOW);
}
else if (key == 'e') {
break;
}
} while (millis() - startTime <= 5000);
}
Re: How set certain time for digitalwrite
Posted: Tue Nov 03, 2015 8:35 am
by joan
You need all the code (apart from main) to put the system into non-blocking I/O. You can't pick and choose which parts might look relevant.
In your main you need to make the calls to set_conio_terminal_mode() at the start, reset_terminal_mode() at the end, and check dataRdy(0) before the getch().
Re: How set certain time for digitalwrite
Posted: Tue Nov 03, 2015 9:24 am
by davenull
hey,
I just was running into this same issue,
now I found this code which is working fine, and even is quite quick:
Code: Select all
#include <termios.h>
#include <unistd.h>
#include <fcntl.h>
int kbhit(void)
{
struct termios oldt, newt;
int ch;
int oldf;
tcgetattr(STDIN_FILENO, &oldt);
newt = oldt;
newt.c_lflag &= ~(ICANON | ECHO);
tcsetattr(STDIN_FILENO, TCSANOW, &newt);
oldf = fcntl(STDIN_FILENO, F_GETFL, 0);
fcntl(STDIN_FILENO, F_SETFL, oldf | O_NONBLOCK);
ch = getchar();
tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
fcntl(STDIN_FILENO, F_SETFL, oldf);
if(ch != EOF)
{
ungetc(ch, stdin);
return 1;
}
return 0;
}
HTH!
Re: How set certain time for digitalwrite
Posted: Tue Nov 03, 2015 10:01 am
by girl71
oops it's better
Re: How set certain time for digitalwrite
Posted: Tue Nov 03, 2015 7:16 pm
by girl71
Re: How set certain time for digitalwrite
Posted: Tue Nov 03, 2015 7:26 pm
by girl71
@ davenull thank you
