Android bluetooth Arduino data receive

/* Electronoobs Bluetooth data receive with
 * Android and Arduino. Small example.
 * Remember to disconnect the Rx and Tx pins of the HC-06 when
 * uploading the code
 * 
 * Subscribe: http://www.youtube.com/c/ELECTRONOOBS
 * Tutorial: http://www.electronoobs.com/eng_arduino_tut20_1.php
 */
//Inputs
int in = A0;

void setup() {
  Serial.begin(9600);
  pinMode(in,INPUT);

}

void loop() {
  //Map the value from 10 bits to 8 bits:
  
  byte val = map(analogRead(in),0,1024.0,0,255);    //Byte = 8 bits = 2 to the 8 = 255  
  Serial.write(val);                                //Serial.write will send only one byte at a time  
  delay(400);                                        //Small delay between each data send  
}

In this case I've used Serial.writet because the data type of the read value is now a byte so 8 bits. 2 to the 8 is 254 so the maximum height of the graph later will be 255. As you can see in the code, before we send the data I map the values from a range of 0 to 1024 to 0 to 255. After each data send I add a small delay in order to make sure I'll be syncronised with the App.

2.3 The App

The App is the same as in the previous aprt as you can see below. But now we add a new horiznotal arrangement and inside it we add a new Canvas with a height of 255 pixels. In the code later we will receive one byte number so the maximum value will be 255. Add the canvas as below and now let's jump to the code part of the app.

2.3.2 The App code Blocks

The time and connection code in this case is the same. We connect using the list piker. Once connected we have to mount the code blocks below. As you can see we have initialized 4 variables. Two for the present x and y data and two more for the previous data. In order to graph the receive data we need the difference between the present and previous data to create a line.

So we initialize those variables with a value of 0 in a number format. Inisde the timer loop as you can see we check for Bluetooth connection once again and if yes we check if there is data to receive. If yes we first give the previous value the present value and next we read the new received value.

As you can see now we receive data with the .ReceiveUnsigned1ByteNumber. In the previous part we received text so we have used the receivedText block. Now we send 1 byte data so we receive 1byte data.
We increase the "X" value each loop so we could plot over the entire graph. Once the "Y" data is saved we create a line between previous and present data using the DrawLine block. In that block the height bust be the total height of the graph minus the received data.

Finally we check if we have reached the maximum width of the graph. If yes, we reseet the Canvas and we start plotting once again from the beginning od the graph and also reset the "X" values to 0.
Now save the app, copy it to the smartphone, install it and open the App. Connect to HC06 and as you can see below we receive data with a range from 0 to 255 and we plot that value. Nice rght?

Quite easy right? You could improve the App any way you want. This was just a small example of what you could do and how to use the Receive.Text or Receive.Number blocks. In the next part we do sommenting a bit different, we receive characters and depending on the received value we control some blocks of the App. Sol let's go.