hey folks,
I've been building a line follower robot which picks up supplies(food,medicines)from the nurse, traverses to the patient's bed waits there till the person takes the supplies and returns to the start point.... it uses 2 sensors for following the line and 9 sensors in the form of 3x3 matrix to find the path it is supposed to go....using hc-05 Bluetooth module i can choose the path, it is supposed to go .... the problem i am facing is after the robot returns back to start point i can't make it stop 
.....I've called functions inside the loop, at the last else if statement in the below code i want the functions to break from the loop and stop the robot so that when i send different inputs like(4,5,6,7) for (forward,left,right,stop) manual mode(Bluetooth remote control).... here is my code
#include <SoftwareSerial.h>
const int ls1=8; //RIGHT
const int ls2=9; //LEFT
const int p1=10; // p1...p9 is matrix
const int p2=11;
const int p3=12;
const int p4=13;
const int p5=A0;
const int p6=A1;
const int p7=A2;
const int p8=A3;
const int p9=A4;
const int ts1=7;
SoftwareSerial BT(0,1); //TX, RX respetively
String readdata;
void linefollower()
{
if(digitalRead(ls1)==LOW&&digitalRead(ls2)==LOW) //moving forward follow the line
{
digitalWrite (3,LOW);
digitalWrite (4,HIGH);
digitalWrite (5,HIGH);
digitalWrite (6,LOW);
}
else if (digitalRead(ls1)==HIGH&&digitalRead(ls2)==LOW) //TURN left
{
digitalWrite (3,HIGH);
digitalWrite (4,LOW);
digitalWrite (5,HIGH);
digitalWrite (6,LOW);
}
else if(digitalRead(ls1)==LOW&&digitalRead(ls2)==HIGH) // TURN right
{
digitalWrite(3, LOW);
digitalWrite (4, HIGH);
digitalWrite(5,LOW);
digitalWrite(6,HIGH);
}
else if (digitalRead(ls1)==HIGH&&digitalRead(ls2)==HIGH) //move forward for 4 seconds
{
digitalWrite (3,LOW);
digitalWrite (4,HIGH);
digitalWrite (5,HIGH);
digitalWrite (6,LOW);
delay(4000);
}
}
void one()
{
if(digitalRead(p2)==HIGH&&digitalRead(p4)==HIGH&&digitalRead(p5)==HIGH&&digitalRead(p7)==HIGH&&digitalRead(p8)==HIGH&&digitalRead(p9)==HIGH&&digitalRead(p1)==LOW&&digitalRead(p3)==LOW&&digitalRead(p6)==LOW) // matrix =number 1
{
digitalWrite (3,LOW);
digitalWrite (4,LOW);
digitalWrite (5,HIGH);
digitalWrite (6,LOW);
delay(5000);
//turn left toward patient bed
}
}
void three()
{
if(digitalRead(p2)==HIGH&&digitalRead(p5)==HIGH&&digitalRead(p7)==HIGH&&digitalRead(p8)==HIGH&&digitalRead(p9)==HIGH&&digitalRead(p1)==LOW&&digitalRead(p3)==LOW&&digitalRead(p4)==LOW&&digitalRead(p6)==LOW) // matrix =number 3
{
digitalWrite (3,LOW);
digitalWrite (4,LOW);
digitalWrite (5,HIGH);
digitalWrite (6,LOW);
delay(5000);
//turn left toward patient bed
}
}
void five()
{
if(digitalRead(p1)==HIGH&&digitalRead(p2)==HIGH&&digitalRead(p4)==HIGH&&digitalRead(p5)==HIGH&&digitalRead(p7)==HIGH&&digitalRead(p8)==HIGH&&digitalRead(p3)==LOW&&digitalRead(p6)==LOW&&digitalRead(p9)==LOW) // matrix =number 5=stop
{
digitalWrite (3,LOW);
digitalWrite (4,LOW); // stop
digitalWrite (5,LOW);
digitalWrite (6,LOW);
delay(5000);
}
}
void tray() // this sensor detects if there is something on the tray or not
{
digitalWrite (3,LOW);
digitalWrite (4,HIGH);
digitalWrite (5,HIGH);
digitalWrite (6,LOW);
delay(5000);
}
void setup() {
// put your setup code here, to run once:
BT.begin(9600);
Serial.begin(9600);
pinMode(ls1,INPUT); //Pin 8 is connected to the output of ir sensor similarly the rest is self explanatory
pinMode(ls2,INPUT);
pinMode(p1,INPUT);
pinMode(p2,INPUT);
pinMode(p3,INPUT);
pinMode(p4,INPUT);
pinMode(p5,INPUT);
pinMode(p6,INPUT);
pinMode(p7,INPUT);
pinMode(p8,INPUT);
pinMode(p9,INPUT);
pinMode(ts1,INPUT);
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
pinMode(6, OUTPUT);
}
void loop() {
// put your main code here, to run repeatedly:
while (BT.available()){
delay(10);
char c = BT.read();
readdata += c; //standard protocol
}
if (readdata.length() > 0) {
Serial.println(readdata);
if(readdata == "1")
{
if (digitalRead(ts1)==LOW)
{ linefollower();
one(); //go to patient one only if there is somthing on the tray
linefollower();
five();
}
else if (digitalRead(ts1)==HIGH) // after the patient takes the food it comes back
{
linefollower();
}
}
else if(readdata == "2")
{
if (digitalRead(ts1)==LOW)
{
linefollower();
three();
linefollower();
five();
}
else if (digitalRead(ts1)==HIGH)
{
linefollower();
// same as readdata=1 here, so far the program runs the way i want to
}
}
else if (readdata == "4") // it should stop when i press 4 but,since everything is stacked on the loop it dosen't
{ // i am poor at programming so please help me instead of trolling
digitalWrite (3, LOW);
digitalWrite (4, LOW);
digitalWrite (5, LOW);
digitalWrite (6, LOW);
delay (100);
return; // i have no idea how to break and return the funtions i have called inside the loop
// or maybe that's not possible any ideas to reformat the program to make it stop and add remote control
}
// thanks 
}
}
