How to use ArduDroid App – Control Arduino from Android via Bluetooth

In this post we’ll learn how to use ArduDroid to control Arduino board in two way communication via Bluetooth using Android smartphone.

This Android App uses Bluetooth to connect Arduino to Android phone using serial Bluetooth Module HC-05 or HC-06.

Using this App, you can read and write to and from all Arduino board pins and ports.

You can read and write to digital ports, you can control PWM ports to write Analog signals, read Analog values from Analog ports and read/write serial data to the Arduino board.

By connecting Arduino board to the Bluetooth module you can gain full control of it.

Normally, the code is opensource so the solution can be customized to your needs and configuration.

Components
Arduino Board
Bluetooth Module HC-05 or HC-06
Android Phone
ArduDroid App

Connection
Connect Arduino to the Bluetooth module as the author has chosen or use your own configuration by changing the Arduino code.

Circuit

Code

/*
PROJECT: ArduDroid 
PROGRAMMER: Hazim Bitar (techbitar at gmail dot com)
DATE: Oct 31, 2013
FILE: ardudroid.ino
LICENSE: Public domain
*/
#define START_CMD_CHAR '*'
#define END_CMD_CHAR '#'
#define DIV_CMD_CHAR '|'
#define CMD_DIGITALWRITE 10
#define CMD_ANALOGWRITE 11
#define CMD_TEXT 12
#define CMD_READ_ARDUDROID 13
#define MAX_COMMAND 20  // max command number code. used for error checking.
#define MIN_COMMAND 10  // minimum command number code. used for error checking. 
#define IN_STRING_LENGHT 40
#define MAX_ANALOGWRITE 255
#define PIN_HIGH 3
#define PIN_LOW 2
String inText;
void setup() {
Serial.begin(9600);
Serial.println("ArduDroid 0.12 Alpha by TechBitar (2013)");
Serial.flush();
}
void loop()
{
Serial.flush();
int ard_command = 0;
int pin_num = 0;
int pin_value = 0;
char get_char = ' ';  //read serial
// wait for incoming data
if (Serial.available() < 1) return; // if serial empty, return to loop().
// parse incoming command start flag 
get_char = Serial.read();
if (get_char != START_CMD_CHAR) return; // if no command start flag, return to loop().
// parse incoming command type
ard_command = Serial.parseInt(); // read the command
// parse incoming pin# and value  
pin_num = Serial.parseInt(); // read the pin
pin_value = Serial.parseInt();  // read the value
// 1) GET TEXT COMMAND FROM ARDUDROID
if (ard_command == CMD_TEXT){   
inText =""; //clears variable for new input   
while (Serial.available())  {
char c = Serial.read();  //gets one byte from serial buffer
delay(5);
if (c == END_CMD_CHAR) { // if we the complete string has been read
// add your code here
break;
}              
else {
if (c !=  DIV_CMD_CHAR) {
inText += c; 
delay(5);
}
}
}
}
// 2) GET digitalWrite DATA FROM ARDUDROID
if (ard_command == CMD_DIGITALWRITE){  
if (pin_value == PIN_LOW) pin_value = LOW;
else if (pin_value == PIN_HIGH) pin_value = HIGH;
else return; // error in pin value. return. 
set_digitalwrite( pin_num,  pin_value);  // Uncomment this function if you wish to use 
return;  // return from start of loop()
}
// 3) GET analogWrite DATA FROM ARDUDROID
if (ard_command == CMD_ANALOGWRITE) {  
analogWrite(  pin_num, pin_value ); 
// add your code here
return;  // Done. return to loop();
}
// 4) SEND DATA TO ARDUDROID
if (ard_command == CMD_READ_ARDUDROID) { 
// char send_to_android[] = "Place your text here." ;
// Serial.println(send_to_android);   // Example: Sending text
Serial.print(" Analog 0 = "); 
Serial.println(analogRead(A0));  // Example: Read and send Analog pin value to Arduino
return;  // Done. return to loop();
}
}
// 2a) select the requested pin# for DigitalWrite action
void set_digitalwrite(int pin_num, int pin_value)
{
switch (pin_num) {
case 13:
pinMode(13, OUTPUT);
digitalWrite(13, pin_value);  
// add your code here      
break;
case 12:
pinMode(12, OUTPUT);
digitalWrite(12, pin_value);   
// add your code here       
break;
case 11:
pinMode(11, OUTPUT);
digitalWrite(11, pin_value);         
// add your code here 
break;
case 10:
pinMode(10, OUTPUT);
digitalWrite(10, pin_value);         
// add your code here 
break;
case 9:
pinMode(9, OUTPUT);
digitalWrite(9, pin_value);         
// add your code here 
break;
case 8:
pinMode(8, OUTPUT);
digitalWrite(8, pin_value);         
// add your code here 
break;
case 7:
pinMode(7, OUTPUT);
digitalWrite(7, pin_value);         
// add your code here 
break;
case 6:
pinMode(6, OUTPUT);
digitalWrite(6, pin_value);         
// add your code here 
break;
case 5:
pinMode(5, OUTPUT);
digitalWrite(5, pin_value); 
// add your code here       
break;
case 4:
pinMode(4, OUTPUT);
digitalWrite(4, pin_value);         
// add your code here 
break;
case 3:
pinMode(3, OUTPUT);
digitalWrite(3, pin_value);         
// add your code here 
break;
case 2:
pinMode(2, OUTPUT);
digitalWrite(2, pin_value); 
// add your code here       
break;      
// default: 
// if nothing else matches, do the default
// default is optional
} 
}

Source: Instructables