De10 standard connects to esp8266 via uart communication by IP uart (rs-232 serial port)

Hello!

Hope you are doing well, need your help with the following issue!

Description:

What i am trying to test out receiving and transmitting with the code i have made the qsys design programmed it wrote the c code, etc. everything works fine as soon as i change the main() to take the data i.e., RX and copy it to char array of TX to write it back on the screen in this case putty it doesn't work idk why. Can you please help me this! Thank you very much!

Code:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/mman.h>
#include <sys/time.h>
#include "ARM_A9_HPS.h"
#include <string.h>

//lw bus; uart
#define HW_REGS_BASE 0xff200000
#define HW_REGS_SPAN 0x00001000
#define HW_REGS_MASK ( HW_REGS_SPAN - 1 )

void uart_putc(char c ,unsigned long *h2p_lw_uart_addr)
{
unsigned short uart_status;
do

{
uart_status = *(h2p_lw_uart_addr + 2);
}while(!(uart_status & 0x40));

*(h2p_lw_uart_addr + 1) = c;
}

void uart_printf(char *str ,unsigned long *h2p_lw_uart_addr)
{
while(*str != '\0')
{
uart_putc(*str ,h2p_lw_uart_addr);
str++;
}
}


int uart_getc(unsigned long *h2p_lw_uart_addr)

{
unsigned short uart_status;
do {
uart_status = *(h2p_lw_uart_addr + 2);
} while (!(uart_status & 0x80));
return *(h2p_lw_uart_addr + 0);
}

int uart_scanf(char *p,unsigned long *h2p_lw_uart_addr)

{
int cnt = 0;
while (1) {
*p = uart_getc(h2p_lw_uart_addr);
cnt++;
if (*p == '\n' || *p == '\r')
return cnt;
else
p++;
}
}

// /dev/mem file id
int fd;

int main()

{

void *virtual_base;

int i;
unsigned long *h2p_lw_uart_addr;

// === get FPGA addresses ==================
// Open /dev/mem
if( ( fd = open( "/dev/mem", ( O_RDWR | O_SYNC ) ) ) == -1 )

{
printf( "ERROR: could not open \"/dev/mem\"...\n" );
return( 1 );
}

//============================================
// get virtual addr that maps to physical
// for light weight AXI bus

virtual_base = mmap( NULL, HW_REGS_SPAN, ( PROT_READ | PROT_WRITE ), MAP_SHARED, fd, HW_REGS_BASE );

if( virtual_base == MAP_FAILED )

{
printf( "ERROR: mmap() failed...\n" );
close( fd );
return( 1 );
}


h2p_lw_uart_addr=(unsigned long*) (virtual_base);//uart
*(h2p_lw_uart_addr + 4) = (int) ((UART_0_FREQ / UART_0_BAUD)-1) ;

char c[20]="Transmitting";

char p[20] = "";

while( 1 )

{
uart_scanf(&p[0],h2p_lw_uart_addr);
usleep(100*1000);

p = c;
uart_printf(&c[0],h2p_lw_uart_addr);
usleep( 100*1000 );
}
}

As just TX works fine (from board) i think qsys implementation is correct and simple too.

Thanks,

Tarun_rai