少废话直接贴代码：
软件环境：android studio 2.2 ;
NDK最好单独下载12r版本就可以； allwinner开发板
1、编写jni头文件及源文件
在main/java同级目录下创建jni文件夹用于存放.h,.c文件
.h文件如下：
/* DO NOT EDIT THIS FILE - it is machine generated */
#include
/* Header for class com_example_beep_GpioCtr */#ifndef _Included_com_example_beep_GpioCtr
#define _Included_com_example_beep_GpioCtr
#ifdef __cplusplus
extern "C" {
#endif
/*
* Class:com_example_beep_GpioCtr
* Method:exportGpio
* Signature: (I)I
*/
JNIEXPORT jint JNICALL Java_com_example_beep_GpioCtr_exportGpio
(JNIEnv *, jclass, jint);
/*
* Class:com_example_beep_GpioCtr
* Method:setGpioDirection
* Signature: (II)I
*/
JNIEXPORT jint JNICALL Java_com_example_beep_GpioCtr_setGpioDirection
(JNIEnv *, jclass, jint, jint);
/*
* Class:com_example_beep_GpioCtr
* Method:readGpioStatus
* Signature: (I)I
*/
JNIEXPORT jint JNICALL Java_com_example_beep_GpioCtr_readGpioStatus
(JNIEnv *, jclass, jint);
/*
* Class:com_example_beep_GpioCtr
* Method:writeGpioStatus
* Signature: (II)I
*/
JNIEXPORT jint JNICALL Java_com_example_beep_GpioCtr_writeGpioStatus
(JNIEnv *, jclass, jint, jint);
/*
* Class:com_example_beep_GpioCtr
* Method:unexportGpio
* Signature: (I)I
*/
JNIEXPORT jint JNICALL Java_com_example_beep_GpioCtr_unexportGpio
(JNIEnv *, jclass, jint);
#ifdef __cplusplus
}
#endif
#endif
.c文件如下：
//
// Created by Administrator on 2018/12/1.
//#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include #include "com_example_beep_GpioCtr.h"#define TAG "jni_gpio"
#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG,TAG ,__VA_ARGS__)
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO,TAG ,__VA_ARGS__)
#define LOGW(...) __android_log_print(ANDROID_LOG_WARN,TAG ,__VA_ARGS__)
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR,TAG ,__VA_ARGS__)
#define LOGF(...) __android_log_print(ANDROID_LOG_FATAL,TAG ,__VA_ARGS__)#define IN0
#define OUT1
#define LOW0
#define HIGH1#define BUFFER_MAX3
#define DIRECTION_MAX 48/*
* Class:com_zhuang_jnigpio_GPIOControl
* Method:exportGpio
* Signature: (I)I
*/
JNIEXPORT jint JNICALL Java_com_example_beep_GpioCtr_exportGpio(JNIEnv *env, jobject instance, jint gpio)
{
char buffer[BUFFER_MAX];
int len;
int fd;
fd = open("/sys/class/gpio/export", O_WRONLY);
if (fd < 0) {
LOGE("Failed to open export for writing!\n");
return(0);
}
LOGE("sizeof(buffer) : %d", sizeof(buffer));
len = snprintf(buffer, BUFFER_MAX, "%d", gpio);
LOGE("gpio : %d , len : %d, buffer : %s , sizeof(buffer) : %d", gpio, len, buffer, sizeof(buffer));
if (write(fd, buffer, len) < 0) {
LOGE("Fail to export gpio!\n");
return 0;
}close(fd);
return 1;
}/*
* Class:com_zhuang_jnigpio_GPIOControl
* Method:setGpioDirection
* Signature: (II)I
*/
JNIEXPORT jint JNICALL Java_com_example_beep_GpioCtr_setGpioDirection(JNIEnv *env, jobject instance, jint gpio, jint direction)
{
static const char dir_str[]= "in\0out";
char path[DIRECTION_MAX];
int fd;
snprintf(path, DIRECTION_MAX, "/sys/class/gpio/gpio%d/direction", gpio);
LOGE("path : %s", path);
fd = open(path, O_WRONLY);
if (fd < 0) {
LOGE("failed to open gpio direction for writing!\n");
return 0;
}if (write(fd, &dir_str[direction == IN ? 0 : 3], direction == IN ? 2 : 3) < 0) {
LOGE("failed to set direction!\n");
return 0;
}close(fd);
return 1;
}/*
* Class:com_zhuang_jnigpio_GPIOControl
* Method:readGpioStatus
* Signature: (I)I
*/
JNIEXPORT jint JNICALL Java_com_example_beep_GpioCtr_readGpioStatus(JNIEnv *env, jobject instance, jint gpio)
{
char path[DIRECTION_MAX];
char value_str[3];
int fd;
snprintf(path, DIRECTION_MAX, "/sys/class/gpio/gpio%d/value", gpio);
fd = open(path, O_RDONLY);
if (fd < 0) {
LOGE("failed to open gpio value for reading!\n");
return -1;
}if (read(fd, value_str, 3) < 0) {
LOGE("failed to read value!\n");
return -1;
}close(fd);
return (atoi(value_str));
}/*
* Class:com_zhuang_jnigpio_GPIOControl
* Method:writeGpioStatus
* Signature: (II)I
*/
JNIEXPORT jint JNICALL Java_com_example_beep_GpioCtr_writeGpioStatus(JNIEnv *env, jobject instance, jint gpio, jint value)
{
static const char values_str[] = "01";
char path[DIRECTION_MAX];
int fd;
snprintf(path, DIRECTION_MAX, "/sys/class/gpio/gpio%d/value", gpio);
fd = open(path, O_WRONLY);
if (fd < 0) {
LOGE("failed to open gpio value for writing!\n");
return 0;
}if (write(fd, &values_str[value =https://www.it610.com/article/= LOW ? 0 : 1], 1) < 0) {
LOGE("failed to write value!\n");
return 0;
}close(fd);
return 1;
}/*
* Class:com_zhuang_jnigpio_GPIOControl
* Method:unexportGpio
* Signature: (I)I
*/
JNIEXPORT jint JNICALL Java_com_example_beep_GpioCtr_unexportGpio(JNIEnv *env, jobject instance, jint gpio)
{
char buffer[BUFFER_MAX];
int len;
int fd;
fd = open("/sys/class/gpio/unexport", O_WRONLY);
if (fd < 0) {
LOGE("Failed to open unexport for writing!\n");
return 0;
}len = snprintf(buffer, BUFFER_MAX, "%d", gpio);
if (write(fd, buffer, len) < 0) {
LOGE("Fail to unexport gpio!");
return 0;
}close(fd);
return 1;
}
2、java初始化本地方法
package com.example.beep;
/**
* Created by Administrator on 2018/12/1.
*/
public class GpioCtr {static {
System.loadLibrary("GpioCtr");
}public final static native int exportGpio(int gpio);
public final static native int setGpioDirection(int gpio, int direction);
public final static native int readGpioStatus(int gpio);
public final static native int writeGpioStatus(int gpio, int value);
public final static native int unexportGpio(int gpio);
}
3、app调用部分代码
package com.example.beep;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.RequiresApi;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
Buzzer bz = new Buzzer();
static int BEEP = 228 ;
static int LED5 = 362;
static int LED6 = 361;
static int flag1 = 0;
static int flag2 = 0;
static int flag3 = 0;
//String out="out";
//String in ="in";
static int out = 1;
static int in = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//bz.export(BEEP);
//bz.export(LED5);
//bz.export(LED6);
GpioCtr.exportGpio(BEEP);
GpioCtr.exportGpio(LED5);
GpioCtr.exportGpio(LED6);
setContentView(R.layout.activity_main);
final Button mybutton1 = (Button) findViewById(R.id.beep);
final Button mybutton2 = (Button) findViewById(R.id.led5);
final Button mybutton3 = (Button) findViewById(R.id.led6);
mybutton1.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
public void onClick(View v) {
if(flag1==0){
flag1 = 1;
v.setBackground(getResources().getDrawable(R.drawable.beep_on));
//bz.gpio(BEEP,out,flag1);
GpioCtr.setGpioDirection(BEEP, out);
GpioCtr.writeGpioStatus(BEEP, flag1);
}else {
flag1 = 0;
v.setBackground(getResources().getDrawable(R.drawable.beep_off));
//bz.gpio(BEEP,in,flag1);
GpioCtr.setGpioDirection(BEEP, in);
GpioCtr.writeGpioStatus(BEEP, flag1);
}
}
});
mybutton2.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
public void onClick(View v) {
if(flag2==0){
flag2=1;
v.setBackground(getResources().getDrawable(R.drawable.light_on));
GpioCtr.setGpioDirection(LED5, out);
GpioCtr.writeGpioStatus(LED5, flag2);
//bz.gpio(LED5,out,flag2);
}else {
flag2=0;
v.setBackground(getResources().getDrawable(R.drawable.light_off));
GpioCtr.setGpioDirection(LED5, in);
GpioCtr.writeGpioStatus(LED5, flag2);
//bz.gpio(LED5,in,flag2);
}
}
});
mybutton3.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
public void onClick(View v) {
if(flag3==0){
flag3=1;
v.setBackground(getResources().getDrawable(R.drawable.light_on));
//bz.gpio(LED6,out,flag3);
GpioCtr.setGpioDirection(LED6, out);
GpioCtr.writeGpioStatus(LED6, flag3);
}else {
flag3=0;
v.setBackground(getResources().getDrawable(R.drawable.light_off));
//bz.gpio(LED6,in,flag3);
GpioCtr.setGpioDirection(LED6, in);
GpioCtr.writeGpioStatus(LED6, flag3);
}
}
});
}
protected void onStop() {
super.onStop();
//bz.unexport(BEEP);
//bz.unexport(LED5);
//bz.unexport(LED6);
GpioCtr.unexportGpio(BEEP);
GpioCtr.unexportGpio(LED5);
GpioCtr.unexportGpio(LED6);
}}4、app/gradle里面添加ndk配置
ndk{
moduleName "GpioCtr" //so文件: lib+moduleName+.so
ldLibs "log", "z", "m" // 添加android日志引用
//abiFilters "all"//cpu的类型
abiFilters "armeabi-v7a", "x86"
}5、local.properties中添加sdk和ndk目录
ndk.dir=D\:\\Users\\Administrator\\AppData\\Local\\Android\\android-ndk-r12b-windows-x86_64\\android-ndk-r12b sdk.dir=D\:\\Users\\Administrator\\AppData\\Local\\Android\\sdk
6、gradle.properties中添加配置
android.useDeprecatedNdk=true（我自己试了这句不加也可以，你们也试试看）
【android|android通过JNI控制GPIO】最后运行安装完成
