printf for Pic32MX170F256B

Question

I'm using harmony for my project and I'm not able to print via the printf function. I'm using UART1 and i have been reading that the standard print channel is UART2. Can someone help me how to redirect to my UART1 channel. Using the U1TXREG then it's possible to send 1 character to my serial port. I'm using internal clock 8MHz. Except for setting up the uart with PPS (U1RXR = 03, RPB3R = 01 and setting the specific rx pin to input all settings remained as setup via harmony. Thanks in advance for your help. Below the main routine..

// *****************************************************************************
// Section: Included Files
// *****************************************************************************
#include <stddef.h>                     // Defines NULL
#include <stdbool.h>                    // Defines true
#include <stdlib.h>                     // Defines EXIT_FAILURE
#include <cstdio>                       // for print instruction
#include "definitions.h"                // SYS function prototypes
#define SYS_FREQ 8000000                // Running at 8MHz
// *****************************************************************************
// Section: Main Entry Point
// *****************************************************************************
void TimerCallBack(uint32_t status, uintptr_t context)
{
   PORTAbits.RA4 = !PORTAbits.RA4; 
}
void delay_us(unsigned int us)
{
    // Convert microseconds us into how many clock ticks it will take
    us *= SYS_FREQ / 1000000 / 2; // Core Timer updates every 2 ticks
    _CP0_SET_COUNT(0); // Set Core Timer count to 0
    while (us > _CP0_GET_COUNT()); // Wait until Core Timer count reaches the number we calculated earlier
}
void delay_ms(int ms)
{
    delay_us(ms * 1000);
}
void _mon_putc (char c)
 {
   while (U1STAbits.UTXBF); // Wait til current transmission is complete
   U1TXREG = c;
}
int main (void)
{
    /*
    ANSELA = 0x00;

    LATA = 0x0;         //      Initial Latch Value 
    TRISA = 0x00;        // All PORTA pins are output 
    ANSELB = 0x00;
    LATB = 0x0;  Initial Latch Value 
    TRISB = 0x00;  Direction Control

    */
/* Initialize all modules */
SYS_Initialize ( NULL );    
TMR2_CallbackRegister(TimerCallBack, 0);
TMR2_Start();
char Test = 'P';

while(1)
{
    U1TXREG = Test;
    //setbuf(stdout, NULL);
    //printf(&quot;counter%d\n&quot;,0);
    PORTBbits.RB4 = !PORTBbits.RB4;
    delay_ms(500);
    PORTBbits.RB4 = !PORTBbits.RB4;
    delay_ms(500);
 }


}
/*******************************************************************************
 End of File
*/

score 1 · Answer 1 · answered Dec 15 '21 at 08:33

You can specify the UART channel by setting the __XC_UART variable before using printf.

/********************************
Dependencies:   xc.h
Processor:      PIC32MX795F512L
Complier:       XC32 v1.32 
Debugger:       Simulator 
********************************/
#include <xc.h>
int main (void)
{
     __XC_UART = 1;  // Code is configured to use UART1 
   printf ("Hello World!\r\n");
   while(1);
   return 0;
 }

See this Microchip FAQ entry: https://microchipdeveloper.com/faq:81

printf for Pic32MX170F256B

1 Answers1