#include <REGX51.H>

//serial
void serialTransmit(unsigned char *ch,unsigned char len);	//To transmit cmd
void serialReceive(void);		//put incoming data into buffer and count cmdIndex

//serial receive
unsigned char cmd[10];			//receive buffer
unsigned char cmdIndex;			//receive buffer counter,if received ,then >0

void main(void)
{
	//serial
	SCON = 0x50;	//Mode 1 , receive enable
	TMOD = 0x20;	//Timer1 : Mode 2
	TH1 = 230;		//baudrate=1200
	TL1 = 230;		//baudrate=1200
	TR1 = 1;
	RI=0;

	while(1)
	{
		serialReceive();	//receive cmd
		
		if(cmdIndex>0)		//incoming cmd received
		{
			serialTransmit("CmdReceived",11);	//response
			
		}
	}
}

/*******************************************
To check if any incoming cmd,put incoming 
data into buffer and count cmdIndex (global)
*******************************************/
void serialReceive(void)
{
	cmdIndex=0;					//cmd length counter
	while(RI)					//check if any incoming data
	{
		cmd[cmdIndex] = SBUF;	//put into buffer
		cmdIndex++;
		RI=0;
		if(cmdIndex>=10)break;	//all 10 bytes received
		while(!RI);				//wait for the next byte
	}
}


/*****************************************
To tramsmit cmd :
*ch = command to be sent
len = length of cmd
*****************************************/
void serialTransmit(unsigned char *ch,unsigned char len)
{
	//transmit
	int i;
	for(i=0;i<len;i++)
	{
		TI = 0;
		SBUF = ch[i];		//send
		while(!TI);			//wait until finished
	}
}