RS485

There's one line that's not right:

LPC_USART3->LCR = 0x83;// Line Control Register LPC_USART3->FCR =0x07;//FIFO buffer

You seem to have code that's commented out.

It looks like that's not the only line like it.

If you want code to be compiled, you have to make sure it's not commented out.

PLEASE SORT OUT THIS PROBLEM AND GET BACK TO US. IT IS IMPERATIVE THAT YOU GET IT TO US AS SOON AS POSSIBLE. IT IS CRITICAL.

WHEN YOUR CHEQUE CLEARS YOUR APPLICATION WILL BE PROCESSED, THERE WILL BE NO EXCEPTIONS...

Hello, The code as follows. Sorry for the inconvenience.
void uart_rs485(void)
{ SCU_PinConfigure(2,3, SCU_CFG_MODE_FUNC2);// p2_3 for U3_TXD
SCU_PinConfigure(2,4, SCU_CFG_MODE_FUNC2);// p2_4 for U3_RXD GPIO_SetDir(4,11,GPIO_DIR_OUTPUT);// Set GIO_B1_RS485_DIR as output

LPC_USART3->LCR = 0x83;// Line Control Register
LPC_USART3->FCR =0x07;//FIFO buffer
LPC_USART3->FDR =0;// Fractional Divide
LPC_USART3->DLM =0;//Divide Latch MSB
LPC_USART3->DLL =98;//Divide Latch LSB
LPC_USART3->LCR =0x03;//Disable DLAB

}
void uart_rs485_transmit(void)
{ GPIO_PinWrite(4,11,1);//Making Transmit Enable high
if(LPC_USART3->LSR & 0x20)
{ LPC_USART3->THR = 83;
} }

void uart_rs485_receive(void)
{ GPIO_PinWrite(4,11,0);//Receive Enable
a = LPC_USART3->RBR;
}

Hi Rajesh,
I have a request to you. Please read the each and every line of the answers you get here. If it is not understandable in first read then read it again and again until it is completely making sense to you. yes sometimes it is difficult for us because of the too much english they use in the answers ;).

So from the first response your questions Andy,

Whoever trying to help you here did not find your post as well presented as they like every professionals do. Again too much expectations on us right..
Your code look like you have a map on scribbles. So he is trying to help you to improve in that area. It is not technically solving your URGENT problem. But believe me you will be needing that anytime soon in your career.

Next, from the second answer you got from B Carutt,
He asking you to uncomment an important line which seems to directly linked to your problem statement. But he also asking you to check the criticality of all other commented lines because he thinks those commented lines seem to be more than just comments.

Next, From the third answer you got from Westonsupermare Pier,
I do not understand the meaning of the sarcasm. If it same to you then just ignore that answer.

Next, from your response,
you did some clean up in your copy pasted code. And added some proper(I assume) register settings. But you failed to mention many information here. They do not know what is the result after you modified the code such as 1.Even after your code change still not able to load the FCR reg? and many more may be (i.e micro, hardware info, details of testing method etc).

And a final note from me, in this forum you do not get the right answers always but always learn something if you're willing. I was once in your shoes.

sorry Carrut. The code id given here. I think you can get it now.

void uart_rs485(void)
{ SCU_PinConfigure(2,3, SCU_CFG_MODE_FUNC2);
SCU_PinConfigure(2,4, SCU_CFG_MODE_FUNC2);
GPIO_SetDir(4,11,GPIO_DIR_OUTPUT);
LPC_USART3->LCR = 0x83;
LPC_USART3->FCR =0x07;
LPC_USART3->FDR =0;
LPC_USART3->DLM =0;
LPC_USART3->DLL =98;
LPC_USART3->LCR =0x03;

}
void uart_rs485_transmit(void)
{ GPIO_PinWrite(4,11,1);//Making Transmit Enable high
if(LPC_USART3->LSR & 0x20)
{ LPC_USART3->THR = 83;
} }

void uart_rs485_receive(void)
{ GPIO_PinWrite(4,11,0);//Receive Enable
a = LPC_USART3->RBR;
}

The chip I am using is LPC1857

void uart_rs485(void)
{ SCU_PinConfigure(2,3, SCU_CFG_MODE_FUNC2);
SCU_PinConfigure(2,4, SCU_CFG_MODE_FUNC2);
GPIO_SetDir(4,11,GPIO_DIR_OUTPUT);
LPC_USART3->LCR = 0x83;
LPC_USART3->FCR =0x07;
LPC_USART3->FDR =0;
LPC_USART3->DLM =0;
LPC_USART3->DLL =98;
LPC_USART3->LCR =0x03;

}
void uart_rs485_transmit(void)
{ GPIO_PinWrite(4,11,1);//Making Transmit Enable high
if(LPC_USART3->LSR & 0x20)
{ LPC_USART3->THR = 83;
} }

void uart_rs485_receive(void)
{ GPIO_PinWrite(4,11,0);//Receive Enable
a = LPC_USART3->RBR;
}

So you really don't believe in indentation for 'C' source code?

Sorry Neil, What you meant by this identation

K. I am following the above told identation.

Hello, Let me know about the PCLK value that should be given for UART communication. How to assign PCLK in mdk5

Hi Dharmaraj, Thanks a lot.I will check that link you have shared.