Android “为什么?”;tcsetattr(fd、TCSANOW、cfg)";总是失败?
我使用了Google的串口API,但是这个函数总是返回-1。我不知道该怎么办 这个项目在我的mac上运行成功,但在我的Windows和Ubuntu上运行错误。在Windows和Ubuntu上,代码总是在Android “为什么?”;tcsetattr(fd、TCSANOW、cfg)";总是失败?,android,c,serial-port,Android,C,Serial Port,我使用了Google的串口API,但是这个函数总是返回-1。我不知道该怎么办 这个项目在我的mac上运行成功,但在我的Windows和Ubuntu上运行错误。在Windows和Ubuntu上,代码总是在tcsettr()中停止,因为它返回-1 这是“SerialPort.c”: 静态速度\u t获得波特率(jint波特率){ 交换机(波特率){ 案例0:返回B0; 案例50:返回B50; 案例75:返回B75; 案例110:返回B110; 案例134:返回B134; 案例150:返回B150;
tcsettr()中停止,因为它返回-1
这是“SerialPort.c”:
静态速度\u t获得波特率(jint波特率){
交换机(波特率){
案例0:返回B0;
案例50:返回B50;
案例75:返回B75;
案例110:返回B110;
案例134:返回B134;
案例150:返回B150;
案例200:返回B200;
案例300:返回B300;
案例600:返回B600;
案例1200:返回B1200;
案例1800:返回B1800;
案例2400:返回B2400;
案例4800:返回B4800;
案例9600:返回B9600;
案例19200:返回B19200;
案例38400:返回B38400;
案例57600:返回B57600;
案例115200:返回B115200;
案例230400:返回B230400;
案例460800:返回B460800;
案例500000:返回B500000;
案例576000:返回B576000;
案例921600:返回B921600;
案例1000000:返回B1000000;
案例1152000:返回B1152000;
案例1500000:返回B1500000;
案例2000000:返回B2000000;
案例2500000:返回B2500000;
案例3000000:返回B3000000;
案例3500000:返回B3500000;
案例4000000:返回B4000000;
默认值:return-1;
}
}
/*
*类别:cedric_serial_SerialPort
*方法:开放式
*签名:(Ljava/lang/String;)V
*/
JNIEXPORT作业对象JNICALL Java\u android\u serialport\u serialport\u open
(JNIEnv*env,jobject-thiz,jstring-path,jint-baudrate)
{
int-fd;
速度;
jobject-mFileDescriptor;
/*检查参数*/
{
速度=getBaudrate(波特率);
如果(速度==-1){
/*TODO:引发异常*/
LOGE(“无效波特率”);
返回NULL;
}
}
/*开启装置*/
{
jboolean-iscopy;
const char*path_utf=(*env)->GetStringUTFChars(env、path和iscopy);
LOGD(“打开串行端口%s”,路径为utf);
fd=开放(路径utf,O_RDWR | O_同步);
LOGD(“open()fd=%d”,fd);
(*env)->释放StringUTFChars(env,path,path_-utf);
如果(fd==-1)
{
/*抛出异常*/
LOGE(“无法打开端口”);
/*TODO:引发异常*/
返回NULL;
}
}
/*配置设备*/
{
结构termios cfg;
LOGD(“配置串行端口”);
if(tcgetattr(fd和cfg))
{
LOGE(“tcgetattr()失败”);
关闭(fd);
/*TODO:引发异常*/
返回NULL;
}
cfmakeraw&cfg;
cfsetispeed(&cfg,速度);
cfsetospeed(和cfg,速度);
中频(tcsetattr(fd、TCSANOW和cfg))
{
//这地方总是有问题
LOGE(“tcsetar()失败”);
关闭(fd);
/*TODO:引发异常*/
返回NULL;
}
}
/* 创建一个相应的文件描述符 */
{
jclass-cFileDescriptor=(*env)->FindClass(env,“java/io/FileDescriptor”);
jMethodIfileDescriptor=(*env)->GetMethodID(env,cFileDescriptor,“,”()V”);
jfieldID descriptorID=(*env)->GetFieldID(env,cFileDescriptor,“descriptor”,“I”);
mFileDescriptor=(*env)->NewObject(env、cFileDescriptor、iFileDescriptor);
(*env)->SetIntField(env,mFileDescriptor,descriptorID,(jint)fd);
}
返回mFileDescriptor;
}
/*
*类别:cedric_serial_SerialPort
*方法:关闭
*签字:()五
*/
JNIEXPORT void JNICALL Java\u android\u serialport\u serialport\u close
(JNIEnv*env,jobject thiz)
{
jclass SerialPortClass=(*env)->GetObjectClass(env,thiz);
jclass FileDescriptorClass=(*env)->FindClass(env,“java/io/FileDescriptor”);
jfieldID mFdID=(*env)->GetFieldID(env,SerialPortClass,“mFd”,“Ljava/io/FileDescriptor;”);
jfieldID descriptorrid=(*env)->GetFieldID(env,FileDescriptorClass,“descriptor”,“I”);
jobject mFd=(*env)->GetObjectField(env,thiz,mFdID);
jint descriptor=(*env)->GetIntField(env,mFd,descriptorID);
LOGD(“关闭(fd=%d)”,描述符;
关闭(描述符);
}
试着用android-ndk-r11c和android.mk编译。。。那么peror
说了什么?如果你写了一个“,”,空格应该在它之后,而不是之前。没有,也没有。这个函数返回-1。我解决了这个问题,实际上问题是ndk的版本。我用了15个,现在是14个
static speed_t getBaudrate(jint baudrate) {
switch(baudrate) {
case 0: return B0;
case 50: return B50;
case 75: return B75;
case 110: return B110;
case 134: return B134;
case 150: return B150;
case 200: return B200;
case 300: return B300;
case 600: return B600;
case 1200: return B1200;
case 1800: return B1800;
case 2400: return B2400;
case 4800: return B4800;
case 9600: return B9600;
case 19200: return B19200;
case 38400: return B38400;
case 57600: return B57600;
case 115200: return B115200;
case 230400: return B230400;
case 460800: return B460800;
case 500000: return B500000;
case 576000: return B576000;
case 921600: return B921600;
case 1000000: return B1000000;
case 1152000: return B1152000;
case 1500000: return B1500000;
case 2000000: return B2000000;
case 2500000: return B2500000;
case 3000000: return B3000000;
case 3500000: return B3500000;
case 4000000: return B4000000;
default: return -1;
}
}
/*
* Class: cedric_serial_SerialPort
* Method: open
* Signature: (Ljava/lang/String;)V
*/
JNIEXPORT jobject JNICALL Java_android_serialport_SerialPort_open
(JNIEnv *env, jobject thiz, jstring path, jint baudrate)
{
int fd;
speed_t speed;
jobject mFileDescriptor;
/* Check arguments */
{
speed = getBaudrate(baudrate);
if (speed == -1) {
/* TODO: throw an exception */
LOGE("Invalid baudrate");
return NULL;
}
}
/* Opening device */
{
jboolean iscopy;
const char *path_utf = (*env)->GetStringUTFChars(env, path, &iscopy);
LOGD("Opening serial port %s", path_utf);
fd = open(path_utf, O_RDWR | O_SYNC);
LOGD("open() fd = %d", fd);
(*env)->ReleaseStringUTFChars(env, path, path_utf);
if (fd == -1)
{
/* Throw an exception */
LOGE("Cannot open port");
/* TODO: throw an exception */
return NULL;
}
}
/* Configure device */
{
struct termios cfg;
LOGD("Configuring serial port");
if (tcgetattr(fd, &cfg))
{
LOGE("tcgetattr() failed");
close(fd);
/* TODO: throw an exception */
return NULL;
}
cfmakeraw(&cfg);
cfsetispeed(&cfg, speed);
cfsetospeed(&cfg, speed);
if (tcsetattr(fd, TCSANOW, &cfg))
{
//There's always a problem in this place
LOGE("tcsetattr() failed");
close(fd);
/* TODO: throw an exception */
return NULL;
}
}
/* 创建一个相应的文件描述符 */
{
jclass cFileDescriptor = (*env)->FindClass(env, "java/io/FileDescriptor");
jmethodID iFileDescriptor = (*env)->GetMethodID(env, cFileDescriptor, "<init>", "()V");
jfieldID descriptorID = (*env)->GetFieldID(env, cFileDescriptor, "descriptor", "I");
mFileDescriptor = (*env)->NewObject(env, cFileDescriptor, iFileDescriptor);
(*env)->SetIntField(env, mFileDescriptor, descriptorID, (jint)fd);
}
return mFileDescriptor;
}
/*
* Class: cedric_serial_SerialPort
* Method: close
* Signature: ()V
*/
JNIEXPORT void JNICALL Java_android_serialport_SerialPort_close
(JNIEnv *env, jobject thiz)
{
jclass SerialPortClass = (*env)->GetObjectClass(env, thiz);
jclass FileDescriptorClass = (*env)->FindClass(env, "java/io/FileDescriptor");
jfieldID mFdID = (*env)->GetFieldID(env, SerialPortClass, "mFd", "Ljava/io/FileDescriptor;");
jfieldID descriptorID = (*env)->GetFieldID(env, FileDescriptorClass, "descriptor", "I");
jobject mFd = (*env)->GetObjectField(env, thiz, mFdID);
jint descriptor = (*env)->GetIntField(env, mFd, descriptorID);
LOGD("close(fd = %d)", descriptor);
close(descriptor);
}