USB Serial for Android - 用Arduino Uno R3發送/接收數據的問題

Question

我正嘗試從Android應用程序向Arduino發送諸如「c」或「s」之類的命令。設備已被識別，但我不確定是否正確發送/接收數據。我正在使用USBSerialforAndroid庫。

當我點擊我的按鈕來開始和停止測量時，吐司通知彈出來表示他們正在經歷，但是當數據「收到」時，我收回「7.00」或「0.00」，我知道這是錯誤的。我覺得它可能在我的Arduino代碼中，或者我是如何從應用程序發送字節的。

下面是相關的Android代碼：

startMeasurement.setOnClickListener(new View.OnClickListener() { 
    @Override 
    public void onClick(View view) { 
     if (selectedSensorType.equals("grade")) { 
     //do nothing 
     } else if (selectedSensorType.equals("height")) { 
      startCode = "c"; 

      heightStart = serialUser(startCode); //get heightFloor from Arduino    
     } else if (selectedSensorType.equals("distance")) { 
      startCode ="s"; 

      distanceStart = 0;    
     } 
    } 
}); 

saveMeasurement.setOnClickListener(new View.OnClickListener() { 
    @Override 
    public void onClick(View view) { 
     if (selectedSensorType.equals("grade")) { 
     check.setText(String.format("%.2f", outputGrade)); 
     } else if (selectedSensorType.equals("height")) { 
     endCode = "c"; 
     heightEnd = serialUser(endCode); //get heightCurb from Arduino 

     double measuredHeight = heightEnd - heightStart; 
     check.setText(String.format("%.2f", measuredHeight)); 
     } else if (selectedSensorType.equals("distance")) { 
     endCode = "e"; 
     distanceEnd = serialUser(endCode); //get distanceEnc from Arduino 

     double measuredDistance = distanceEnd - distanceStart; 
     check.setText(String.format("%.2f", measuredDistance)); 
     } 
    } 
}); 

這裏是我的serialUser（）方法：

private double serialUser(String command) { 
     double output = 0; 
     if (mSerialDevice != null) { 
      byte[] commandArray = command.getBytes(); 
      byte[] returnArray = new byte[8]; 

      try { 
       mSerialDevice.setBaudRate(115200); 
       mSerialDevice.write(commandArray, 1000); 
       output = mSerialDevice.read(returnArray, 2500); 
      } catch (IOException e) { 
       e.printStackTrace(); 
      } 
     } 
     return output; 
    } 

這裏是我的Arduino代碼：

void setup() 
{ 
    Serial.begin(115200); 
    Dist.begin(2,3); 
} 

const double Pi = 3.14159265359; // 3.141593, set to 1 for testing purposes 
double encoderPosition = -999; 

void loop() 
{ 
    double newPosition = abs(myEnc.read()); // gets raw data, 1440 ticks = 1 rev 
    double revs = newPosition/(double)960; // calculates number of revs 
    double diameter = 15; // specify wheel diameter 
    double distanceEnc = diameter*Pi*revs; // calculates distance 
    double heightDiff; 
    int timesum = 0; 

    distanceEnc = round(distanceEnc*1000.0l)/1000.0l; // round distance to 3 decimal places 

    if (newPosition != encoderPosition) { // write new position to serial 
    encoderPosition = newPosition;  
    //Serial.println(distanceEnc,3); 
    //Serial.println(revs,3); 
    } 

    while (Serial.available()) { // if a character is sent to the device, the encoder reading resets to zero 

    byte incomingCommand = Serial.read(); 
    if (incomingCommand == 's'){   
     myEnc.write(0); 
     revs = 0; 
    } 
    if (incomingCommand == 'e'){   
     Serial.println(distanceEnc,3); 
    } 
    if (incomingCommand == 'f'){ 
     time = Dist.getDistanceTime(); 
     heightFloor = (float) time/(148.00);  
     Serial.println(heightFloor); 
    } 
    if(incomingCommand =='c'){  
     for(int i=1; i<11; i++){ 
     times[i] = Dist.getDistanceTime(); 
     delay(100); 
     timesum = timesum+times[i];} 

    time = timesum/(int)10; 
     heightCurb = (float) time/(148.00); 
     heightDiff = heightFloor - heightCurb;  
     Serial.println(heightCurb); 
    } 
    } 
} 

Answer 1

我用來自開發人員示例文件夾的示例來構建工作應用程序。

https://github.com/mik3y/usb-serial-for-android/tree/master/usbSerialExamples

檢查這些了，看你可以用它來做什麼。