Doubt regarding usage of a certain function in 8051 based bluetooth home automation

I have read your project of 8051 based bluetooth control home automation.After understanding I implemented it but the bluetooth didn't give any response.Later I read your code and used the function Serialwrite(0x0d) and it worked.Without this statement the bluetooth is not responding.My question is transmitting 0x0d ,what does that signify?

Yes aditya you have to write 0x0d everytime  before you send a data.

Accordig to ASCII table the value 0x0d represetns carriage return (Enter key). So the blutooth module should recevice a carriage return everytime before you send the data 

  Joined May 19, 2015      213
Tuesday at 03:45 PM

I have read about carriage return.It is simply putting cursor to first position.Could you explain why just putting a cursor in first position (carriage return) is very much important?

  Joined April 19, 2018      5
Thursday at 09:41 AM

You net to read the bluetooth datasheet if you wanna get more into it.

During a communication data is always appended by /n/r where /n stands for new line this new line is given by the carriage return which is mandatory in our case. This is how the luetooth module will know that its the end of data and it should transmit what ever was received so far.

Hope you get the point 

  Joined May 19, 2015      213
Tuesday at 03:45 PM

The ASCII code 0x0d used in 8051 is similar to the press enter for completion of data, while using serial monitor on Arduino IDE to send serial data to sperfic board. In one of my projects, I used a new development board by SSLA, the board (EFB-IoT) is of IoTs functionality & as well as with Bluetooth BLE functionality, to access data over bluetooth. I suggest you to try this advanced product also in your projects.

  Joined April 09, 2020      55
Thursday at 02:40 PM