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Altera_Forum
Honored Contributor I
787 Views

Writing to UART

Simple code, trying to write to UART from terminal and light an LED if character "A" is detected. What am i doing wrong? here is the code. The manual of UART is here under \devices: http://www-ug.eecg.toronto.edu/msl/nios.html 

# include <stdio.h># define RS232_UART_DATA ((volatile int*) 0x10001010)# define RS232_UART_CONTROL ((volatile int*) (0x10001010+4)) 

volatile int*LED =(int*)0x10000010; 

 

 

int main() 

 

 

unsigned char *pinput; 

 

while(*pinput){ 

//strings in C are zero terminated 

 

//if room in output buffer 

if((*RS232_UART_DATA)&0xffff0000 )  

//then read the next character 

*(pinput)= *RS232_UART_DATA;  

if (pinput =='A'){ 

*(LED)=1; } 

 

 

 

 

}
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2 Replies
Altera_Forum
Honored Contributor I
31 Views

Check your compiler warnings. 'pinput' is an uninitialized pointer variable and it's entirely possible it is pointing at garbage memory containing a zero when your program starts.

Altera_Forum
Honored Contributor I
31 Views

do confirm if the value that pinput is holding when any car detected.

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