hwa/st/stm32/examples/01-1-blink/main.c

Blink a LED using a software loop

This program enables the LED port, configures the LED pin as a digital output, then in an infinite loop it toggles the LED state and waits for half the period to be elapsed.

make run to try the program. The LED should blink.

Symbols:

• BOARD_H is the name of the target board definition file. It can be specified at compile time via the command line. If not, the Makefile will set it to a default value. For example, make BOARD=mini-stm32-v3.0 will lead to BOARD_H defined as <boards/mini-stm32-v3.0.h>. See STM32 Development boards for the list of board definition files provided.
• PIN_LED1 is the name of the I/O pin at which a LED1 is connected. It is defined in the target board header file.
• PERIOD is the blinking period.
• HW_DEVICE_HSIHZ is the CPU frequency.

main.c

 
/*  This file is part of the HWA project.
 *  Copyright (c) 2017 Christophe Duparquet.
 *  All rights reserved. Read LICENSE.TXT for details.
 */
 
#include BOARD_H
 
#define PERIOD          0.5
 
 
int main ( )
{
  hw( power, (LED,port), on );
 
  hw( configure, LED,
      mode,      digital_output,
      frequency, lowest );
 
  for(;;) {
    hw( toggle, LED );
    hw_waste_cycles( PERIOD/2 * HW_DEVICE_HSIHZ );
  }
}