从蓝牙hc05到Android接收传感器值

Question

I'm sending sensor values from Arduino via an HC-05 Bluetooth module to Android. I'm receiving the values but they are not showing properly in my textviews.

I'm using 2 sensors and their values are like this (example first sensor = 120, 97, 110 etc)

Sensor2 values are like this (97, 96, 100 etc) ie values are changing.

Now my Android code is:

if (msg.what == handlerState) {
  //if message is what we want
  String readMessage = (String) msg.obj;
  // msg.arg1 = bytes from connect thread
  recDataString.append(readMessage);
  //keep appending to string until ~
  int endOfLineIndex = recDataString.indexOf("~");
  // determine the end-of-line
  if (endOfLineIndex > 0) {
    // make sure there data before ~
    String dataInPrint = recDataString.substring(0, endOfLineIndex);
    // extract string
    if (recDataString.charAt(0) == '#') {
      //if it starts with # we know it is what we are looking for
      String sensor0 = recDataString.substring(1, 3);
      //get sensor value from string between indices 1-5
      String sensor1 = recDataString.substring(4, 6);
      //same again...
      heart_rate.setText(sensor0);
      // update the textviews with sensor values
      temperature.setText(sensor1);
    }
    recDataString.delete(0, recDataString.length());
    //clear all string data
    dataInPrint = " ";
  }
}

When I receive 2-digit data on sensor 1 like this (76) and 2-digit data also on sensor 2 (97) it shows the data properly. But if values are greater than 3 digits the values don't show up properly and some digits of the first textview appear on the second textview. I think the problem is getting the data between the indices. How can I manage this? Please help me.

Sorry for my bad English, I'm not a native speaker.

Answer 1

It looks like your current substring statements will only get 2 digits worth of information per sensor since the function excludes final index. You are currently only getting chars at 2,3 and then 5,6. Consider sending an individual string for each sensor value and then using a certain character to denote the end of the value so that the length of the value doesn't matter.