The Definitive Guide to ARM® Cortex®-M0 and Cortex-M0+ Processors, 2nd Edition

18.2. Handling printf

18.2.1. Overview

Based on the examples in the previous section, we can create our own string printing function to handling printing of text strings, as shown below.

// Uart string output

void UART_puts(char ∗ mytext)

{

  char CurrChar;

  CurrChar = ∗mytext;

  while (CurrChar != (char) 0x0){

    UART_putc(CurrChar);  // Normal data

    mytext++;

    CurrChar = ∗mytext;

    }

  return;

}

This works great for printing constant strings. We can also use this function to print other information by using sprint function to print the information to a text buffer, and then output it using UART_puts, the string output function we created:

char txt_buf[30];

…

sprintf(txt_buf,"%d∖n",1234);

UART_puts(txt_buf);

However, it would also be useful if we can ...