STM32F4DISCOVERY sample – lighting randomly LEDs

Based on the IO_Toggle example, a little sample program, that lights up random LED’s based on the STM32F4 true random number generator.

/**
******************************************************************************
* @file IO_Toggle/main.c
* @author MCD Application Team
* @version V1.0.0
* @date 19-September-2011
* @brief Main program body
******************************************************************************
* @attention
*
* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
* TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
* DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
* FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
* CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*
* <h2><center>&copy; COPYRIGHT 2011 STMicroelectronics</center></h2>
******************************************************************************
*/

/* Includes ------------------------------------------------------------------*/
#include "stm32f4_discovery.h"

/** @addtogroup STM32F4_Discovery_Peripheral_Examples
* @{
*/

/** @addtogroup IO_Toggle
* @{
*/

/* Private typedef -----------------------------------------------------------*/
GPIO_InitTypeDef GPIO_InitStructure;

/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
void Delay(__IO uint32_t nCount);
void RNG_Config(void);
/* Private functions ---------------------------------------------------------*/

/**
* @brief Main program
* @param None
* @retval None
*/
int main(void)
{

uint32_t random32bit = 0;

/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f4xx.s) before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f4xx.c file
*/

/* GPIOD Periph clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);

/* Configure PD12, PD13, PD14 and PD15 in output pushpull mode */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13| GPIO_Pin_14| GPIO_Pin_15;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOD, &GPIO_InitStructure);

/* RNG configuration */
RNG_Config();

while (1)
{

/* Wait until one RNG number is ready */
while(RNG_GetFlagStatus(RNG_FLAG_DRDY)== RESET)
{

}

/* Get a 32bit Random number */
random32bit = RNG_GetRandomNumber();

GPIO_Write(GPIOD, (random32bit&0xF)<<12) ;

/* Insert delay */
Delay(0x7FFFFF);

}
}

/**
* @brief Delay Function.
* @param nCount:specifies the Delay time length.
* @retval None
*/
void Delay(__IO uint32_t nCount)
{
while(nCount--)
{
}
}

void RNG_Config(void)
{
/* Enable RNG clock source */
RCC_AHB2PeriphClockCmd(RCC_AHB2Periph_RNG, ENABLE);

/* RNG Peripheral enable */
RNG_Cmd(ENABLE);
}

#ifdef USE_FULL_ASSERT

/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */

/* Infinite loop */
while (1)
{
}
}
#endif

/**
* @}
*/

/**
* @}
*/

/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/