port vin arduino ? question about HC-06 in proteus

Hello every one it's my first time in this forum I hope you will help me . I want to know please what the pin " vin" in arduino is for ? and my second question I want to simulate an RC boat with bluetooth in proteus i did the shema above but i didn't find this pin so i used a DC 5V instead. but when i activate bluetooth on my pc and when I choose the port 4 in my bluetooth card to connect it with my phone and then start the simulation, my app on android appears always disconnected even before simulation

I want to know please what the pin " vin" in arduino is for ?

For powering the Arduino instead of using the power input jack.

I want to simulate an RC boat with bluetooth in proteus

For most embedded projects simulators are useless because they don't simulate the external modules.

@Grumpy_Mike thank you very much but is it true that this "vin" dangerous for the arduino and it can destroy it ?

but is it true that this "vin" dangerous for the arduino and it can destroy it ?

No.
Well it is only true in the respect that any Arduino pin can destroy the Arduino if you do something stupid with it. What stupid thing are you thinking of doing?

HHHHHHHHHHHHHH the thing shown in the picture in the beginning

Then the answer is no there is no danger using the Vin. Although 6V is a bit low, you might need at least 6.5 to 7V minimum.

i have a battery of 9V. Thank you very very much again

i have a battery of 9V

Is it one of those small square ones used in smoke alarms? If so they are useless for driving motors as they have a very limited current capacity.

Also replace the motors at first with LEDs to test. Then add the motor. This is because motors generate interference that could stop the Arduino or the bluetooth receiver from working correctly. Especially as you have no supply decoupling on the motor's supply.

I tried to replace them with LEDs but it's not working !!!

What doesn't work?
The code you have not posted? The schematic you have not posted?

Have you tested each component one at a time? If so what sketch? If no why not?

I tried all what is in the schematic but when i make an order by my phone i heard a low sound coming from my DC motors I think that's because the value of resistances is too high (1M Ohms et 100K Ohms) what do you think @Grumpy_Mike

I have no idea what is happening round the 1M / 100K resistors. Why are you even feeding them into an analogue input. A layout diagram is almost impossible to read. You have to turn it into a schematic in your head and you have to look up what that pin does on the chip. That is why a schematic is much better. Also you have posted no code so I don't know if that analogue pin is being used as an input or an output.
In general for a potential divider the resistor from input to ground should be 10K.

Good morning Mike... well here is the code :

/*

  • Created by Vasilakis Michalis // 26-12-2014 ver.1
  • Project: Control RC Boat / Vessel via Bluetooth with Android Smartphone
  • More information at www.ardumotive.com
    */

//L293 Connection
const int motorA1 = 5; // Pin 2 of L293
const int motorA2 = 6; // Pin 7 of L293
const int motorB1 = 10; // Pin 10 of L293
const int motorB2 = 9; // Pin 14 of L293
//Bluetooth (HC-06 JY-MCU) State pin on pin 2 of Arduino
const int BTState = 2;
//Calculate Battery Level
const float maxBattery = 8.0;// Change value to your max battery voltage level!
int perVolt; // Percentage variable
float voltage = 0.0; // Read battery voltage
int level;
// Use it to make a delay... without delay() function!
long previousMillis = -100010;// -100010=-10sec. to read the first value. If you use 0 then you will take the first value after 10sec.
long interval = 100010; // interval at which to read battery voltage, change it if you want! (101000=10sec)
unsigned long currentMillis; //unsigned long currentMillis;
//Useful Variables
int state;
int vSpeed=200; // Default speed, from 0 to 255

void setup() {
// Set pins as outputs:
pinMode(motorA1, OUTPUT);
pinMode(motorA2, OUTPUT);
pinMode(motorB1, OUTPUT);
pinMode(motorB2, OUTPUT);
// Initialize serial communication at 9600 bits per second:
Serial.begin(9600);
}

void loop() {

//Save income data to variable 'state'
if(Serial.available() > 0){
state = Serial.read();
}

//Change speed if state is equal from 0 to 4. Values must be from 0 to 255 (PWM)
if (state == '0'){
vSpeed=0;}
else if (state == '1'){
vSpeed=100;}
else if (state == '2'){
vSpeed=180;}
else if (state == '3'){
vSpeed=200;}
else if (state == '4'){
vSpeed=255;}

/Forward*****/
//If state is equal with letter 'F', boat will go forward!
if (state == 'F') {
analogWrite(motorA1, vSpeed); analogWrite(motorA2, 0);
analogWrite(motorB1, vSpeed); analogWrite(motorB2, 0);
}
/Forward Left**/
//If state is equal with letter 'G', boat will go forward left
else if (state == 'G') {
analogWrite(motorA1, 100); analogWrite(motorA2, 0);
analogWrite(motorB1, vSpeed); analogWrite(motorB2, 0);
}
/Forward Right**/
//If state is equal with letter 'I', boat will go forward right
else if (state == 'I') {
analogWrite(motorA1, vSpeed); analogWrite(motorA2, 0);
analogWrite(motorB1, 100); analogWrite(motorB2, 200);
}
/Backward*****/
//If state is equal with letter 'B', boat will go backward
else if (state == 'B') {
analogWrite(motorA1, 0); analogWrite(motorA2, vSpeed);
analogWrite(motorB1, 0); analogWrite(motorB2, vSpeed);
}
/Backward Left**/
//If state is equal with letter 'H', boat will go backward left
else if (state == 'H') {
analogWrite(motorA1, 0); analogWrite(motorA2, 100);
analogWrite(motorB1, 0); analogWrite(motorB2, vSpeed);
}
/Backward Right**/
//If state is equal with letter 'J', boat will go backward right
else if (state == 'J') {
analogWrite(motorA1, 0); analogWrite(motorA2, vSpeed);
analogWrite(motorB1, 0); analogWrite(motorB2, 100);
}
/Left**/
//If state is equal with letter 'L', wheels will turn left
else if (state == 'L') {
analogWrite(motorA1, 0); analogWrite(motorA2, vSpeed);
analogWrite(motorB1, vSpeed);analogWrite(motorB2, 0);
}
/Right**/
//If state is equal with letter 'R', wheels will turn right
else if (state == 'R') {
analogWrite(motorA1, vSpeed);analogWrite(motorA2, 0);
analogWrite(motorB1, 0); analogWrite(motorB2, vSpeed);
}

/Stop*****/
//If state is equal with letter 'S', stop the boat
else if (state == 'S'){
analogWrite(motorA1, 0); analogWrite(motorA2, 0);
analogWrite(motorB1, 0); analogWrite(motorB2, 0);
}
/Battery******/
//Read battery voltage every 10sec.
currentMillis = millis();
if(currentMillis - (previousMillis) > (interval)) {
previousMillis = currentMillis;
//Read voltage from analog pin A0 and make calibration:
voltage = (analogRead(A0)*5.015 / 1024.0)11.132;
//Calculate percentage...
perVolt = (voltage
100)/ maxBattery;
if (perVolt<=75) { level=0; }
else if (perVolt>75 && perVolt<=80) { level=1; } // Battery level
else if (perVolt>80 && perVolt<=85) { level=2; } //Min ------------------------ Max
else if (perVolt>85 && perVolt<=90) { level=3; } // | 0 | 1 | 2 | 3 | 4 | 5 | >
else if (perVolt>90 && perVolt<=95) { level=4; } // ------------------------
else if (perVolt>95) { level=5; }
Serial.println(level);
}

}

how to control with bluetooth hc-05, any app??
i have arduino, 2 motor, bluetooth hc-05, l9110 motor controler, 1 servo, battery, then how to make?