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How to run the Nios II Hello world small example using the rs232 module in combintation with max232?

//---------------------------------------- // C program for controlling BERTv1_0 // Author: Michael James Basford // Created: 29/06/2018 // Version: 1.0 // Date last edited: 21/11/2019 //----------------------------------------     //Include headers #include "sys/alt_stdio.h" #include <stdio.h> //#include "altera_avalon_uart_regs.h" #include "altera_avalon_pio_regs.h" #include <stdlib.h> #include <string.h> #include <stdint.h>     //Definitions #define CONTROL_BASE 0x9030 #define TOTAL_BIT_BASE 0x9040 #define INC_BIT_BASE 0x9050   //Function prototypes void writeControl(int control); int readTotalBits(void); int readIncorrectBits(void); void _short_delay(int count); void delay(int a); char *inputString(FILE* fp, size_t size);     //Main int main(void){ alt_putstr("Hello from Nios II bert!\n");   printf("UoN BERT v1_0 \n\n"); printf("Startup...\n"); delay(5);   while(1){   char *m;   printf("Ready. For help send 'h'. \n\n");   m = inputString(stdin, 10);   if(strcmp("start", m) == 0){ //if strings ARE equal printf("Resetting values - "); writeControl(0b10); //Reset regs printf("done!\n"); writeControl(0b11); //Begin count printf("Counting... Please wait.... \n\n"); _short_delay(48000000); //Delay   writeControl(0b01); //Stop counting, don't reset   printf("Finished count.\n");   unsigned int totalbits = readTotalBits(); unsigned int incorrectbits = readIncorrectBits();   printf("Total bits: %d \n", totalbits); printf("Incorrect bits: %d \n", incorrectbits); printf("You need to do the maths at this point ;P \n\n");   printf("Please wait... DO NOT SEND COMMANDS\n\n"); delay(4);   }   else if(strcmp("h", m) == 0) { printf("Valid command(s) v1_0:\n"); printf("'start' - begins counting and returns BER after set duration.\n \n"); }   else{ printf("Error - Not a recognised command. Send 'h' for help.\n \n"); }   free(m); //Free up the received string }   return 0; }     //Write to Control Reg //[1:0] //[1] Start/Enable //[0] reset void writeControl(int control){   IOWR_ALTERA_AVALON_PIO_DATA(CONTROL_BASE, control);   }     //Read from total bits reg //[31:0] //[31:0] total number of bits sent int readTotalBits(){   int totalbits = IORD_ALTERA_AVALON_PIO_DATA(TOTAL_BIT_BASE); return totalbits; }     //Read from incorrect bits reg //[31:0] //[31:0] total number of incorrect bits int readIncorrectBits(){   int incorrectbits = IORD_ALTERA_AVALON_PIO_DATA(INC_BIT_BASE); return incorrectbits;   }     //Performs precise delay //asm between "" marks //increments of 1us approx. void _short_delay(volatile int count) {   asm(" ;\ ldw r2,0(sp) ;\ movi r3,-1 ;\ loop: ;\ add r2,r2,r3 ;\ bne r2,r3,loop ;\ "); }     //Performs a less precise delay //around 1s duration void delay(int a){   volatile int i = 0; while(i<a*1000000){ i++;   }   }     //Input string buffer, resizes with size of string //Memory freed in main() char *inputString(FILE* fp, size_t size){ char *str; int ch; size_t len = 0; str = realloc(NULL, sizeof(char)*size);//size is start size if(!str)return str; while(EOF!=(ch=alt_getchar(fp)) && ch != '\n'){ str[len++]=ch; if(len==size){ str = realloc(str, sizeof(char)*(size+=16)); if(!str)return str; } } str[len++]='\0';   return realloc(str, sizeof(char)*len); }

Hello everyone.

I wanted to communicate data over serial port. At first I used the Jtag Uart Intel Fpga module. In this part I was able to see the incoming data in the Nios II console.

Then I wanted to communicate the same data using the rs232 module and a custom board (find the schematic below) in which a max232 is the interface without succeess.

I was wondering what can be wrong but I don't know where is my mistake. I have taken a look to the configurations in the Qsys as well as the Nios II code.

Could someone here please tell me what I'm doing wrong?

Thanks in advance. Below you can find my configurations and the Nios II code.

Config1.pngrs232fpga.png

 

module.png

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New Contributor III
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I don't see a standard UART in your QSYS system. Do you have an RS232 UART (search the IP catalogue) connected to your processor?

 

Cheers,

Alex

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