Using serial communication without pc

Can you provide a block diagram of what your describing, ie. do you have two arduino's one in the car and one for the remote control, both with radios , the one in the car connected to the speed and steering im assuming with PWM control. the other with buttons or something to act as user controls because without the connection to the PC there is no commands going to the transmitter.

also (And sorry if this is obvious), if the one connected to the PC was powered by the PC then it wont have power once disconnected ?

hence a block diagram would help us help you

You're a bit confusing, serial communication means sending data on a single communication channel bit by bit, hence it's name. Usb also does serial communication as rs232 but at a way faster rates and using different protocols. You want your robot to be controlled from a computer or from a remote control? If you want to get rid of your arduino's and just use the microcontrollers (atmega328), well you can either way (pc or remote), you just have to adapt the software on both microcontrollers and setup the fuses for external clock to use without arduino boards. Here's a useful link Arduino - ArduinoToBreadboard

This is the block diagram of the system I wanted to build. the remote control contains the buttons I require and the receiver end is mounted on my car.

I used the command Serial.print to transmit the data and the command Serial.read to receive the data. These two commands work only when the serial monitors are open. I wanted to know if there is a way to use these two commands without keeping the serial monitor open.

Thank you sir, the link was helpful. I wanted to use my arduino as remote control and receiver on the car which works without a computer. I want my robot to be controlled by a remote control. Sorry for the confusion with the serial communication, I just wanted to tell about the Serial.print and Serial.read commands.

What are the radio modules and also the Arduino models, there are many alternatives but I would be reluctant  to say without knowing what your working with

And to answer your original question, yes there is a way to do it without the PC connected, just need the info requested to get it right for you

Thanks

There are many considerations to take in account:

-instead of using "serial.print" which is a display command, try using "serial.write" to transmit data (http://arduino.cc/en/Serial/Print#.UyoIPIXPsvw)

-have you used the virtualwire library?

-it's well known that cheap 434MHz rf modules are "what you pay is what you get" so you might aswell get delays and corrupted transmission from them even with the increase of the length of the antenna, when you have obstacles and interference. Don't expect large distances operations, these modules work in amplitude shift keying for low performance applications (http://en.wikipedia.org/wiki/Amplitude-shift_keying)

Hi,
I have same problem.
what  I am doing.wifi module connect with arduino and use Software serial communication,
when I plug arduino to pc and open serial monitor then my programe is execute.
but I dont want this."I want to directly start my program when i applied the power to the arduino".

so plz suggest me
thanks

The program should always start the moment you connect power, once uploaded

When you plug in a PC is will reset the program and start it again and if your monitoring the hardware serial it will reflect that

If your using software serial for the WIFI then this should not be impacted, so my only conclusion is you may have something in your code testing to see if the hardware serial is connected and if not it waits

Please provide your code so we can check it

#include <SoftwareSerial.h>

String str;

int c=1;

SoftwareSerial mySerial(10, 11); // RX, TX

void setup() {

  setpins();

pinMode(13,OUTPUT);

  // set the data rate for the SoftwareSerial port

  mySerial.begin(4800);

  wificonnect();

  gotIP();

  delay(3000);

}

void setpins()

{

  pinMode(1,OUTPUT);

  pinMode(2,OUTPUT);

  pinMode(3,OUTPUT);

  pinMode(4,OUTPUT);

  pinMode(5,OUTPUT);

  pinMode(6,OUTPUT);

  pinMode(7,OUTPUT);

  pinMode(8,OUTPUT);

  pinMode(9,OUTPUT);

}

void gotIP()

{

if(mySerial.find("GOT IP"))

{

}else{

  gotIP();

  }

}

void wificonnect()

{

if(mySerial.find("CONNECTED"))

{

}

else{

   mySerial.println("AT+CWJAP=\"ganesh\",\"123456789gg\"");

delay(2000);

wificonnect();

}

}

void loop() { // run over and over

  delay(1000);

  if(c==1)

  {

    mySerial.println("AT+CIPMUX=1");

  }

  if(c==2)

  {

   mySerial.println("AT+CIPSTART=0,\"TCP\",\"GANESH.XP3.BIZ\",80");

  delay(2000);

  }

  if(c==3)

  {

     mySerial.println("AT+CIPSEND=0,50");

delay(2000);

    mySerial.println("POST /index.php HTTP/1.0");

    mySerial.println("HOST: GANESH.XP3.BIZ");

    mySerial.println();mySerial.println();mySerial.println();mySerial.println();

  }

if(mySerial.available())

{

  String str1=mySerial.readString();

if(str1.indexOf("OK") and c==1)

{

  c=2;

}

if(str1.indexOf("NECT")>0 and c==2)

{

  c=3;

}

if(str1.indexOf("IPD")>0)

{int temp1=0,temp=0;

  for(int i=str1.indexOf(";");i<str1.length();i++)

  {

    if(str1[i]==',')

    {

      if(temp1!=0)

      {

        if(temp==0){

        digitalWrite(temp1,LOW);         

        }

        if(temp==1){

        digitalWrite(temp1,HIGH); 

        }

      }

      temp1=0;temp=0;

    }

    else if(str1[i]==':')

    {

      temp1=temp;

      temp=0;

    }

    else

    {

      temp=temp*10+(((int)str1[i])-48);

    }

  }

  c=1;

}

if(str1.indexOf("ERROR")>0 or str1.indexOf("is not valid")>0)

{

  c=1;

  delay(3000);

}

}

}

:this code run after serail monitor open......if its close then only LED 13 blink ...no data transfer or receive from the esp8266 module

thanks

When working with wifi or RF communication devices, you should first make sure that they work over a hardline, where it is easier to resolve the protocol and message traffic.

Then you can go to freespace with a level of uncertainty eliminated so that you only need to debug the RF devices.

DAB