Receiving AT command response from HC-05

Projects Programming
1

Hello All,
This is my first post so request mods to assist me in the right category if I have chosen the incorrect one.

My Arduino UNO is connected with the bluetooth module -HC-05 via TX/RX pins. So I am using hardware serial. I also connected a constant 3.3V on the PIN 34 of HC-05 to enable AT mode.

When I use the Serial monitor and send AT commands, everything works perfectly. Command "AT" receives a response "OK" in the serial monitor.

Now for my project I need to use the response of the AT command within my code.

I have tried to print the response in a serial monitor as well on LCD but result is same.
I know I am missing something. Any help would be highly appreciated.

Thanks in advance.

My code:

#include <LiquidCrystal.h>
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

void setup()
{
 lcd.begin(16, 2);
 lcd.setCursor(0, 0);
 lcd.print("Connecting..");
 lcd.setCursor(0, 1);
 lcd.print("                    ");
 delay(1000);
 Serial.begin(38400);

 ConnectHC();
}

void ConnectHC()
{
 char incoming;
 char incomingstr;
 char str[2];
 byte i = 0;
 lcd.clear();
 lcd.setCursor(0, 0);
 delay(1000);
 Serial.print("AT+RESET\r\n");                     //send to HC-05 RESET
 while (Serial.available() > 0)
 {

   if (i < 2)
   {
     incoming = Serial.read();
     str[i] = incoming;                             //put received char to str
     i++;
     str[i] = '\0';

     lcd.print(str[i]);                              //printing the return value
   }

 }
}

void loop()
{
 //Nothing here
}
2

The code you posted improperly does not even compile. So, any talk of it working is nonsense. Read the stickies at the top of the forum and post your real code properly.

3

Please post your whole program using code tags having read how to post a programming question

Apart from anything else the function in the code snippet that you posted has at least one error in it that would stop it compiling so we need to see the actual code that you are having problems with.

Another tip. Before posting your code use Ctrl/T in the IDE to format it.

4

It was just a code snippet to give you guys some idea.
Anyways, will post the entire code shortly. Thanks again.

5

It was just a code snippet to give you guys some idea.

We got some ideas, all right. Not ones that you wanted us to have, I imagine. Don't repeat that mistake again. Make new ones next time. 8)

6

updated with the complete code that I am using now.

7 
     i++;
     str[i] = '\0';

     lcd.print(str[i]);                              //printing the return value

Look, carefully, at this code. What, EXACTLY, are you printing?

8

PaulS:

     i++;

str[i] = '\0';

lcd.print(str[i]);                              //printing the return value



Look, carefully, at this code. What, EXACTLY, are you printing?

Aaah..Sorry. Ignore that. I was playing with different combinations.

9

May be I am too tired to figure out this. I used that function in the Loop and it was working.
So I knew the delay was required.
And then I started looking into other Serial commands and found out this wonderful - SerialreadString()

With Serial.readString(), I dont even need to have a while loop to get all the response.
Now its working :slight_smile:

Code, if it helps others

String incoming;
Serial.print("AT");                                    //Issue AT command to HC-05
Serial.print("\r\n");                                  //New line
delay(1000);                                           //This is required to wait for the serial activity

incoming = Serial.readStringUntil('\n\r');      //Reads entire response as a String 
lcd.print(incoming);                                //Finally prints the String