hwa/st/stm32/examples/05-2-uart/main.c

Use of the UART.

main.c

 
/*  This file is part of the HWA project.
 *  Copyright (c) 2021 Christophe Duparquet.
 *  All rights reserved. Read LICENSE.TXT for details.
 */
 
#include BOARD_H
 
#define AHBHZ           HW_DEVICE_HSIHZ         // AHB frequency
#define APBHZ           AHBHZ
 
#define UART            usart2
#define UART_TX         (porta,2)
 
 
int main ( )
{
  hwa( begin, reset );
 
  /*  Power the controllers we use
   */
  /* hwa( power, (LED3,port), on ); */
  hwa( power, (UART_TX,port), on );
  hwa( power, UART, on );
  hwa( commit );
 
  hwa( configure, UART_TX, function, (UART,tx), mode, digital_output );
  
  hwa( configure,       UART,
       mode,            uart,
       divider,         AHBHZ/10000,    // 10 kbps
       /* clockhz,              APBHZ, */
       /* bps,          100000, */
       /* tol,          0.01, */
       databits,        8,
       parity,          none,
       stopbits,        1,
       receiver,        off,
       transmitter,     on,
       run,             yes );
 
  hwa( commit );
 
  //   Sleep between IRQs.
  //
  //  for(;;) hw( wait, irq );
 
  for (;;) {
    while ( hw(read,(UART,txe)) != 1 ) {}
    hw_waste_cycles( 0.003*AHBHZ );
    hw( write, (UART,dr), '.' );
    //    hw( write, (UART,dr), '\x7F' );
    //    hw_waste_cycles( 0.02*AHBHZ );
    //    hw( toggle, UART_TX );
  }
}