[SOLVED] Uart1_Data_Ready() always returns true

[K33rg4t3]

Hey!
I am creating RS232 communication on PIC16F628A.
I am able to send a string to the computer and receive it in hyper terminal.
But I am haveing troubles with doing "Echo" application. It looks like Uart1_Data_Ready() is always returning true, and my PIC is spamming empty "Letter received" messages to PC.
Here is my code:

void main() {
　　 int count;
　　 char buff[64];
　CMCON = 7;　　　 // Disable Comparators
　UART1_Init(9600);　　 // Baud Rate 9600
　Delay_ms(100);
　TRISA = 0;　　　　　
　TRISB = 0;　　　
　count = 0;
　while(1) {
　　// every some time send the string
　　if(count >= 255) {
　　　　　UART1_Write_Text(" UART Test Successful! ");　 // Character Message to be Sent
　　　　　UART1_Write(10); // Line Feed
　　　　　UART1_Write(13); // Carriage Return
　　　　　 count = 0;
　　　　　　PORTA ^= 0x7;
　　}
// if something is received
　　if(UART1_Data_Ready())
　　{
   // read and reply
　　 int r = UART1_Read();
　　 buff[0] = r;
　　 buff[1] = 0;
　　　　　UART1_Write_Text("Letter: ");
　　　　　UART1_Write_Text(buff);
　　　　　UART1_Write(10); // Line Feed
　　　　　UART1_Write(13); // Carriage Return
　　　　　 count = 0;
　　}
　　count++;
　　delay_ms(1);　　
　}
}

The problem is that I am getting "Letter: " messages all the time in the PC. Please help.

 

[pic.programmer]

Problem with TRISB ?

Rx pin on PORTB should be configured as input pin using TRISB.

 

[K33rg4t3]

Problem with TRISB ?

Rx pin on PORTB should be configured as input pin using TRISB.

Exacly! It works now! Thanks!

 

[andre_luis]

I'm intrigued to know how the portB pin would be related to the original question.

 

[K33rg4t3]

I'm intrigued to know how the portB pin would be related to the original question.

RB1 has RX function and RB2 is TX. And I was setting TRISB after initializing the UART, thus overwriting the correct settings...

 

[andre_luis]

Sure, I forgot to complete the argument, that a priori would be not necessary to thange PortB settings. It is a good practice to place initialization functions for peripherals right after I/O pins configuration.