【TLE9869】+ A7.板载电位器ADC测试

[limale]

开发板上有一个10K的电位器连接到P2.4引脚可以用作ADC的测试，前一贴使用SPI驱动了屏幕刚好我们可以把AD转换的电压值显示到屏幕上。

对于TLE9869来说，ADC模块最高可以达到10位的转换精度，具体的特性如下所示：

25 10-Bit Analog Digital Converter (ADC1)

25.1 Features

The principal features of the ADC1 are:

? Up to 8 analog input channels (channel 7 reserved for future use)

? Flexible results handling

- 8-bit and 10-bit resolution

? Flexible source selection due to sequencer

- insert one exceptional sequence (ESM)

- insert one interrupt measurement into the current sequence (EIM), single or up to 128 times

- software mode

? Conversion sample time (separate for each channel) adjustable to adapt to sensors and reference

? Standard external reference (VAREF) to support ratiometric measurements and different signal scales

? DMA support, transfer ADC conversion results via DMA into RAM

? Support of suspend and power saving modes

? Result data protection for slow CPU access (wait-for-read mode)

? Programmable clock divider

? Integrated sample and hold circuitry

转换模式有多种可选，这里我们选择正常序列模式。

使用IFXConfigWizard来生成初始化头文件，八个序列都选择上通道4即可。

main.c文件：

uint16 mV;

bool value_valid;

char str[16] = {0};

int main(void)

{

  /*****************************************************************************

  ** initialization of the hardware modules based on the configuration done   **

  ** by using the IFXConfigWizard                                             **

  *****************************************************************************/

  SCU_Init();

  INT_Init();

  Port_Init();

  SSC1_Init();

  OLED_Init();

  OLED_Fill();

  OLED_Clear();

    Adc1_Init();

    VAREF_Enable();

  /*****************************************************************************

  ** place your application code here                                         **

  *****************************************************************************/

  /*****************************************************************************

  ** main endless loop                                                        **

  *****************************************************************************/

/*lint -e716 info while(1) ... */

/*lint -e9036 Supressing MISRA 2012 Rule 14.4 */

  while (1)

/*lint -e9036 */

/*lint -e716 */

  {

    /***************************************************************************

    ** main watchdog1 (WDT1) service                                          **

    ***************************************************************************/

/*lint -e534 Supressing MISRA 2012 MISRA 2012 Directive 4.7 */

    WDT1_Service();

/*lint +e534 */

    /***************************************************************************

    ** place your application code here                                       **

    ***************************************************************************/

        OLED_ShowString(0,0,"Infineon",16);

        OLED_ShowString(0,2,"**TLE9869 Poti**",16);

        OLED_ShowString(0,4,"******demo******",16);

        value_valid = Adc1_GetChResult_mV(&mV, ADC1_CH4);

        if (value_valid == true)

        {

            sprintf(str,"V = %1.3f",mV*0.001);

            OLED_ShowString(0,6,str,16);

        }

  }

}

上个图看看效果，很直观。