STM32 ADC sättigt zu früh

/*

* adc_test.c

*

* Created: 18.02.2014

*  Author: Nicolas

*/

#include <stdio.h>

#include "../../ioMapping.h"

#include "../src_encoder/key.h"

#include "../src_avrcom/pgmspace.h"

#include "../src_avrcom/delay.h"

#include "../src_glcd/glcd_ks0108.h"

#ifdef STM32F10x

  #include "stm32f10x_adc.h"

  #include "stm32f10x_gpio.h"

  #include "stm32f10x_rcc.h"

#elif defined(STM32F4xx)

  #error "only for STM32F10x implemented yet"

#else

  #error "unknown MCU"

#endif

//#define POTI_UPDWN_GPIO  GPIOC

//#define POTI_UPDWN_Pin   GPIO_Pin_3

//#define POTI_UPDWM_ADCCH ADC_Channel_13

void adc_calib(ADC_TypeDef *ADCx) {

  ADC_Cmd(ADCx,ENABLE);

  ADC_ResetCalibration(ADCx);

  while(ADC_GetResetCalibrationStatus(ADCx));

  ADC_StartCalibration(ADCx);

  while(ADC_GetCalibrationStatus(ADCx));

  ADC_SoftwareStartConvCmd(ADCx,ENABLE);

}

/* Suchen von I2C-Devices und Darstellen auf LCD */

void adc_test(void) {

  ADC_InitTypeDef  ADC_InitStructure;

  GPIO_InitTypeDef GPIO_InitStructure;

  uint16_t value;

  // ADC-Takt max. 14MHz, hier 72MHz / 6 = 12MHz

  RCC_ADCCLKConfig(RCC_PCLK2_Div6);

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC,ENABLE);

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_ADC1,ENABLE);

  GPIO_InitStructure.GPIO_Pin = POTI_UPDWN_Pin;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_Init(POTI_UPDWN_GPIO,&GPIO_InitStructure);

  ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;

  ADC_InitStructure.ADC_DataAlign          = ADC_DataAlign_Right;

  ADC_InitStructure.ADC_ExternalTrigConv   = ADC_ExternalTrigInjecConv_None;

  ADC_InitStructure.ADC_Mode               = ADC_Mode_Independent;

  ADC_InitStructure.ADC_NbrOfChannel       = 1;

  ADC_InitStructure.ADC_ScanConvMode       = DISABLE;

  ADC_Init(ADC1,&ADC_InitStructure);

  ADC_RegularChannelConfig(ADC1,POTI_UPDWM_ADCCH,1,ADC_SampleTime_1Cycles5);

  ADC_Cmd(ADC1,ENABLE);

  ADC_SoftwareStartConvCmd(ADC1,ENABLE);

  adc_calib(ADC1);

  printf_P(PSTR("\fADC Test Poti 1 \n\a"));

  // Kann als Dauerschleife angesehen werden

  while(!key_getstroke()) {

    value = ADC_GetConversionValue(ADC1);

    glcd_setpos(128);

    printf_P(PSTR("val=%6i\a"),value);

    delay_us(100);

  }

  printf_P(PSTR("\b\b\b\bdone.    \a"));

  return;

  error:

  printf_P(PSTR("\nError \a"));

  while(!key_getstroke());

} // end function