How to switch program in arduino using android app?

Question

I have 2 programs made for my arduino.The first one is for solving a maze automatically and the second one is for controlling the robot with a android app.I wanted to control the robot with the app I made as soon as it has finished solving the maze. Is it possible to upload both the program in the arduino and run it one at a time?If so can you tell me how?

• Butzke: Why don't you make just one program to run all?
• U Zuno Kunno: Never mind I just found the solution.Thank you for your reply though.
• Majenko: If you know the solution you should post it as an answer.
• U Zuno Kunno: The answer is a little bit complicated.I'll post it as soon as possible.

Answer 1

Once I made a sketch to run multiple programs. I wrote a setup and loop function for every different "program", (e.g. setup_p1, setup_p2, ... loop_p1, ...) and then wrote a simple main sketch to handle them all.

In my application I choose the program at startup with a 3-dipswitch, but you can easily switch this to allow "on the fly" switching.

I choose to use a callback because it's faster than just checking the mode every time, at least in my case

// callback for loop function
typedef void (*loopfunction)();
loopfunction currentloop;
void setup()
{
 // Set dip-switch pins as input
 pinMode(MODE_PIN2,INPUT_PULLUP);
 pinMode(MODE_PIN1,INPUT_PULLUP);
 pinMode(MODE_PIN0,INPUT_PULLUP);
 // Concatenate the dip-switch values
 byte mode = 7 - ((digitalRead(MODE_PIN2) << 2) | (digitalRead(MODE_PIN1) << 1) | digitalRead(MODE_PIN0));
 // choose the correct mode
 switch(mode)
 {
 case 0: // Shutdown - do nothing
 break;
 case 1: // Program 1
 setup_p1();
 currentloop = loop_p1;
 break;
 case 2: // Program 2
 setup_p2();
 currentloop = loop_p2;
 break;
 ...
 }
 // Not a valid program: halt
 if (!currentloop)
 {
 while(1);
 }
}
void loop()
{
 // Execute the current loop
 currentloop();
}