Reading Multiple Sensor Values via Bluetooth

[ahmet_satilmis]

Hi, I have reading 2 sensor values via Bluetooh and send them to App Inventor. To display this values i used clock but the both sensor values writed on the same label.Please help.

//Arduino Code
//Subscribe if u feel it is helpful

// code starts here
char Incoming_value = 0; // for bluetooth
int sensor_pin = A0; // Soil Sensor input at Analog PIN A0
int output_value ;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
pinMode(13, OUTPUT);
Serial.begin(9600);
pinMode(4,OUTPUT);
Serial.begin(9600);
Serial.println("Reading From the Sensor ...");
delay(2000);
}

// put your main code here, to run repeatedly:

void loop() {
output_value= analogRead(sensor_pin);
output_value = map(output_value,550,10,0,100);

Serial.print(output_value);
Serial.println("%");
if(Serial.available() > 0)
{
Incoming_value = Serial.read();
Serial.print(Incoming_value);

if(Incoming_value == '1')             
  digitalWrite(13, HIGH);  
else if(Incoming_value == '0')       
  digitalWrite(13, LOW);   

}

 Serial.print("|"); 

if(output_value<0){
digitalWrite(4,HIGH);
}
else{
digitalWrite(4,LOW);
}
delay(1000);

int val = analogRead(A1); // read input value

Serial.println(val);

delay(1000);
}
//Code ends here

//Btech Kids

[Joel]

In your arduino code you are sending the values separately not together are you not?

So I believe what's happening is half is sending then you app clock goes and you only have half the data so it sets it as label one then it's called again and the second half has printed so that is also set to label one. Try sending all the data on arduino at once and that should fix it

[ABG]

Standard advice:

Please see the Delimiter article in FAQ

FAQ Section: Bluetooth < version 4 (BlueTooth Client) and Arduino

Arduino HC-06 tutorials Arduino USB - Pavitra and Thunkable Arduino via USB Delimiter usage for receiving one message per ReadText DHT22 Temperature or Humidity, no Clock - kio4.com How to send CR the hard way http://www.martyncurrey.com/android-mit-app-inventor-auto-connect-to-bluetooth/ Instructables YouTube course on Arduino/AI2 - Magesh Jayakumar Martyn Arduino Bluetooth sketch Sending Slider Data to Arduino - Neil Kenyon Turning a LED on and off with an Arduino, a HC-06 and Andr…

Be sure to use println() at the end of each message to send from the sending device, to signal end of message. Do not rely on timing for this, which is unreliable.

In the AI2 Designer, set the Delimiter attribute of the BlueTooth Client component to 10 to recognize the End of Line character.

Also, return data is not immediately available after sending a request,
you have to start a Clock Timer repeating and watch for its arrival in the Clock Timer event. The repeat rate of the Clock Timer should be faster than the transmission rate in the sending device, to not flood the AI2 buffers.

In your Clock Timer, you should check

  Is the BlueTooth Client still Connected?
  Is Bytes Available > 0?
     IF Bytes Available > 0 THEN
       set message var  to BT.ReceiveText(-1) 

This takes advantage of a special case in the ReceiveText block:

ReceiveText(numberOfBytes)
Receive text from the connected Bluetooth device. If numberOfBytes is less than 0, read until a delimiter byte value is received.

If you are sending multiple data values per message separated by | or comma, have your message split into a local or global variable for inspection before trying to select list items from it. Test if (length of list(split list result) >= expected list length) before doing any select list item operations, to avoid taking a long walk on a short pier. This bulletproofing is necessary in case your sending device sneaks in some commentary messages with the data values.