我使用Android USB主机连接USB磁盘，我想读写数据到USB磁盘，但是当我发送bulkTransfer失败时 .
收到的缓冲区 (strBuf) 为空，没有收到字节 . 我想这可能是发送到usb设备的字节 （bytes_w） 不对，但我不知道它 .
这是我的代码：
private String findInterface() {
boolean foreClaim = true;
byte[] bytes_w = null;
byte[] bytes_r = new byte[1024];
byte[] send_command = {(byte)0xef, 0x01,(byte) 0x80, 0x01, 0x00,0x00, 0x00,0x00,0x00,0x00 };
byte[] receive_result = {(byte) 0xef, 0x02};
int TIMEOUT = 0;
StringBuffer strBuf_send = new StringBuffer();
StringBuffer strBuf_receive = new StringBuffer();
if ( device == null ) {
return " " + -2;
}else {
intf = device.getInterface(0);
epIN = intf.getEndpoint(0); //0 -in read
epOUT = intf.getEndpoint(1); // 1- out write
connection = uManager.openDevice(device);
if ( !connection.claimInterface(intf, foreClaim)) {
connection.close();
}
bytes_w = send_command;
int w= connection.bulkTransfer(epOUT, bytes_w, bytes_w.length, 3000);
int r = connection.bulkTransfer(epIN, bytes_r, bytes_r.length, 3000);
for (int i=0; i<bytes_r.length; i++) {
if (bytes_r[i] != 0) {
strBuf_send.append(bytes_r[i] + "," );
}
}
bytes_w = receive_result;
int w2= connection.bulkTransfer(epOUT, bytes_w, bytes_w.length, 3000);
int r2 = connection.bulkTransfer(epIN, bytes_r, bytes_r.length, 3000);
// read returned buffer
for (int i=0; i<bytes_r.length; i++) {
if (bytes_r[i] != 0) {
strBuf_receive.append(bytes_r[i] + "," );
}
}
return " write: " + w + ", read:" + r + "read buffer " + strBuf_send.toString() +
" write: " + w2 + ", read:" + r2 + "read buffer " + strBuf_receive.toString() ;
}
1 回答
我无法确定您是否设置了发送和接收数据的波特率 . 当我尝试在我的应用程序中设置通信时，这是我第一次遇到的问题 .
如果您希望波特率为9600，请编写以下内容：