notes/C code for Griffin Technology PowerMate USB Knob-Zz3UgjEu.sh
/*
* Copyright (c) 2017 Kris Occhipint.
* http://filmsbykris.com
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <linux/input.h>
#include <string.h>
#include <stdio.h>
static const char *const evval[2] = {
"RELEASED",
"PRESSED "
};
int main(void){
//get input device
const char *dev = "/dev/input/by-id/usb-Griffin_Technology__Inc._Griffin_PowerMate-event-if00";
struct input_event ev;
ssize_t n;
int fd;
//open device for reading
fd = open(dev, O_RDONLY);
//exit on error opening device
if (fd == -1) {
fprintf(stderr, "Cannot open %s: %s.\n", dev, strerror(errno));
return -1;
}
while (1) {
n = read(fd, &ev, sizeof ev);
//printf("%d\n",ev.type);
//printf("%d\n",(int)ev.value);
if(ev.type == 2 && (int)ev.value == 1){
printf("Clock Wise\n");
}else if(ev.type == 2 && (int)ev.value == -1){
printf("Counter Clock Wise\n");
}
if (ev.type == EV_KEY && ev.value >= 0 && ev.value <= 2){
printf("%s 0x%04x (%d)\n", evval[ev.value], (int)ev.code, (int)ev.code);
}
}
return 0;
}