从Arduino HC-05蓝牙向Android发送数据的正确方法是什么？

Question

我正在尝试将Arduino HC-05的浮动数据发送到Android。我接收数据的android代码是

format-number()

我无法将字节缓冲区解析为float。我试过谷歌搜索，但没有帮助。谁能告诉我我做错了什么？

我得到的字符串是一些带问号的未知字符。

下面是我的Aurdino代码：

byte buffer[];
            buffer = new byte[2048];
            int bytes = dataInputStream.read(buffer);
            if(bytes > 0) {
                String message = new String(buffer, 0, bytes);
                Log.i(TAG, "listen: " + message);
            }

void loop（） {

double duration, distance,FrontSensor,LeftSensor;

}

我得到的输出是：

Answer 1

我会改用以下代码：

rm(list = ls())
library(shiny)

ui <- fluidPage(
  sidebarPanel(
    div(style="display: inline-block;vertical-align:top; width: 150px;",selectInput("ddllgra", "Function:",c('mean','median','sd','count','min','max'), selected='mean')),
    div(style="display: inline-block;vertical-align:top; width: 100px;",HTML("<br>")),
    div(style="display: inline-block;vertical-align:top; width: 150px;",textInput(inputId="xlimitsmax", label="x-max", value = 0.5))),
  mainPanel()
)
server <- shinyServer(function(input,output){})
shinyApp(ui, server)

这对我来说是从Arduino获取蓝牙信息的！ ：）

编辑：要在arduino中使用double to string转换值：

//create new class for connect thread private class ConnectedThread extends Thread { private final InputStream mmInStream; private final OutputStream mmOutStream; //creation of the connect thread public ConnectedThread(BluetoothSocket socket) { InputStream tmpIn = null; OutputStream tmpOut = null; try { //Create I/O streams for connection tmpIn = socket.getInputStream(); tmpOut = socket.getOutputStream(); } catch (IOException e) { } mmInStream = tmpIn; mmOutStream = tmpOut; } public void run() { byte[] buffer = new byte[256]; int bytes; // Keep looping to listen for received messages while (true) { try { bytes = mmInStream.read(buffer); //read bytes from input buffer String readMessage = new String(buffer, 0, bytes); // Send the obtained bytes to the UI Activity via handler bluetoothIn.obtainMessage(handlerState, bytes, -1, readMessage).sendToTarget(); } catch (IOException e) { break; } } } //write method public void write(String input) { byte[] msgBuffer = input.getBytes(); //converts entered String into bytes try { mmOutStream.write(msgBuffer); //write bytes over BT connection via outstream } catch (IOException e) { //if you cannot write, close the application Toast.makeText(getBaseContext(), "Connection Failure", Toast.LENGTH_LONG).show(); finish(); } } }

Answer 2

这可能会有所帮助。

int charsRead = 0;
char[] buffer = new char[BUFFER_SIZE];
while (mRun)
{
    charsRead = in.read(buffer);
    serverMessage = new String(buffer).substring(0, charsRead);
        if (serverMessage != null && mMessageListener != null) {
             Log.e("RESPONSE FROM SERVER", "S: Received Message: '" + serverMessage + "'");
        }
    serverMessage = null;
}