Initial version

3 files changed, 117 insertions, 0 deletions

diff --git a/README.txt b/README.txt
new file mode 100644
index 0000000..b4c028a
--- /dev/null
+++ b/README.txt
@@ -0,0 +1,7 @@
+Simple program, that read from interrupt generated by connecting the
+selected pin to a rotary dial.
+
+Use init_3.4.sh to enable the pin in the kernel, and then run "rotor".
+
+Please note that this program is written for linux-sunxi kernel.
+
diff --git a/init_3.4.sh b/init_3.4.sh
new file mode 100755
index 0000000..9852ddf
--- /dev/null
+++ b/init_3.4.sh
@@ -0,0 +1,5 @@
+modprobe gpio-sunxi
+
+echo 15 > /sys/class/gpio/export 
+echo in > /sys/class/gpio/gpio15_pb2/direction
+echo rising > /sys/class/gpio/gpio15_pb2/edge 
diff --git a/rotor.c b/rotor.c
new file mode 100644
index 0000000..f6121f4
--- /dev/null
+++ b/rotor.c
@@ -0,0 +1,105 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <poll.h>
+
+#include <sys/time.h>
+#include <time.h>
+
+#define MAX_BUF 64
+
+struct timespec diff(struct timespec start, struct timespec end)
+{
+	struct timespec temp;
+	if ((end.tv_nsec-start.tv_nsec)<0) {
+		temp.tv_sec = end.tv_sec-start.tv_sec-1;
+		temp.tv_nsec = 1000000000+end.tv_nsec-start.tv_nsec;
+	} else {
+		temp.tv_sec = end.tv_sec-start.tv_sec;
+		temp.tv_nsec = end.tv_nsec-start.tv_nsec;
+	}
+	return temp;
+}
+
+int main( int argc, char** argv )
+{
+    struct pollfd fdset[2];
+
+    int nfds = 2;
+    int gpio_fd, timeout, rc;
+    char buf[MAX_BUF];
+    int len;
+    int number=0;
+    struct timespec now_ts, then_ts, diff_ts;
+    bool firstInt; // the next interrupt is the first of the sequence
+    
+
+    gpio_fd = open( "/sys/class/gpio/gpio15_pb2/value", O_RDONLY | O_NONBLOCK );
+    timeout = 500;
+    
+
+    clock_gettime(CLOCK_MONOTONIC, &then_ts);
+    
+    firstInt=true;    
+
+    while (1) {
+
+	memset((void*)fdset, 0, sizeof(fdset));
+	memset((void*)buf,0,sizeof(buf));
+
+	fdset[0].fd = 0;
+	fdset[0].events = POLLIN;
+     
+	fdset[1].fd = gpio_fd;
+	fdset[1].events = POLLPRI;
+
+	rc = poll(fdset, nfds, timeout);      
+
+	if (rc < 0) {
+		fprintf(stderr,"\npoll() failed!\n");
+		return -1;
+	}
+	
+        // scaduto il timeout senza interrupt
+	if (rc == 0) {
+		// printf(".");
+		if (number > 0) {
+        		printf("%d\n\n", number % 10);
+        		number=0;
+                }
+	}
+            
+	if (fdset[1].revents & POLLPRI) {
+                clock_gettime(CLOCK_MONOTONIC, &now_ts);
+                // printf("%d %d - ", now_ts.tv_sec, now_ts.tv_nsec);
+                diff_ts = diff(then_ts, now_ts);
+                then_ts = now_ts;
+	        lseek(fdset[1].fd,0,SEEK_SET);
+		len = read(fdset[1].fd, buf, MAX_BUF);
+//		printf("\npoll() GPIO %d interrupt occurred\n", 34);
+                strtok(buf,"\n");
+
+                int sec=diff_ts.tv_sec;
+                float msec=diff_ts.tv_nsec/1000000.0;
+
+
+                printf("value [%s] sec %d msec %f\n",buf,sec,msec);
+                
+                if (firstInt || msec > 90) number++;
+                firstInt=false;
+	}
+
+	if (fdset[0].revents & POLLIN) {
+		(void)read(fdset[0].fd, buf, 1);
+		fprintf(stderr, "\npoll() stdin read 0x%2.2X\n", (unsigned int) buf[0]);
+	}
+
+        fflush(stdout);
+    }
+    
+
+}