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--- products:sbc:common:applications:gsensor [2022/06/29 21:51]
127.0.0.1 external edit
+++ products:sbc:common:applications:gsensor [2026/02/03 22:53] (current)
gray update by using AI
@@ Line 1: / Line 1: @@
-# Gsensor
+====== G-Sensor ======
+===== Introduction =====
+This guide explains how to identify the G-Sensor device node and read acceleration data from it using a C program.
+===== System Configuration =====
+Verify the G-Sensor device node exists:
+```shell
+$ ll /dev/accel
+```
+Expected output:
+```shell
+crw-rw-rw- 1 root root 10, 50 Mar 18 12:17 /dev/accel
+```
+===== Demo Source Code =====
+The following sample program demonstrates reading data from the G-Sensor using default settings. You can extend it to implement other functions.
+```c gsensor_sample_data.c
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#define GBUFF_SIZE                12
+#define GSENSOR_IOCTL_MAGIC       'a'
+#define GSENSOR_IOCTL_INIT              _IO(GSENSOR_IOCTL_MAGIC, 0x01)
+#define GSENSOR_IOCTL_RESET             _IO(GSENSOR_IOCTL_MAGIC, 0x04)
+#define GSENSOR_IOCTL_CLOSE             _IO(GSENSOR_IOCTL_MAGIC, 0x02)
+#define GSENSOR_IOCTL_START             _IO(GSENSOR_IOCTL_MAGIC, 0x03)
+#define GSENSOR_IOCTL_GETDATA           _IOR(GSENSOR_IOCTL_MAGIC, 0x08, char[GBUFF_SIZE+1])
+#define GSENSOR_IOCTL_APP_SET_RATE      _IOW(GSENSOR_IOCTL_MAGIC, 0x10, short)
+#define GSENSOR_IOCTL_GET_CALIBRATION   _IOR(GSENSOR_IOCTL_MAGIC, 0x11, int[3])
+struct sensor_axis {
+    int x;
+    int y;
+    int z;
+};
+char *gsensor_device = "/dev/accel";
+int gsensor_fd = -1;
+int main(int argc, char **argv){
+        struct sensor_axis gsensor_data;
+        gsensor_fd = open(gsensor_device, O_RDWR);
+        if (0 > gsensor_fd){
+                printf("gsensor node open failed ...\n");
+                exit(-1);
+        }else{
+                printf("gsensor node open success!!!\n");
+        }
+        if(ioctl(gsensor_fd, GSENSOR_IOCTL_START, NULL) == -1) {
+                printf("gsensor start failed ... \n");
+                close(gsensor_fd);
+                exit(-1);
+        }else{
+                printf("gsensor start sueecss !!!\n");
+        }
+        printf("start to get gsensor data ...\n");
+        while(1){
+                if(ioctl(gsensor_fd, GSENSOR_IOCTL_GETDATA, &gsensor_data) == -1) {
+                        printf("gsensor get data faile ... \n");
+                        close(gsensor_fd);
+                        exit(-1);
+                }
+                printf("gsensor_data -- x:%d,y:%d,z:%d \n", gsensor_data.x, gsensor_data.y, gsensor_data.z);
+                sleep(1);
+        }
+        close(gsensor_fd);
+		return 0;
+}
+```
+Compile the program:
+```shell
+$ gcc -o gsensor_sample_demo gsensor_sample_demo.c
+```
+===== Demonstrate =====
+Run the compiled program. While it is running, tilt or move the board to observe changes in the acceleration values.
+```shell
+$ sudo ./gsensor_sample_demo
+gsensor node open success!!!
+gsensor start sueecss !!!
+start to get gsensor data ...
+gsensor_data -- x:-2112,y:16,z:16448
+gsensor_data -- x:-2128,y:176,z:16128
+gsensor_data -- x:-1632,y:2784,z:15968
+gsensor_data -- x:7440,y:-3760,z:14608
+gsensor_data -- x:-512,y:-7280,z:12128
+gsensor_data -- x:-14384,y:-2336,z:11280
+gsensor_data -- x:9952,y:-5264,z:15216
+gsensor_data -- x:-6432,y:3760,z:24896
+```

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