Design and Implementation of EADC Sampling External Voltage Program Based on NUC442

1. Introduction to NUC442

　　NUC442 is a Cortex ® -M4F core processor with DSP and floating point unit, working frequency up to 84 MHz, embedded 256/512K /flash, 64K/SRAM. There are abundant peripheral resources on the chip. Because the official BSP package is too confusing and complicated, I studied ADC 1 in EADC. The PID of the NUC442JI8AE development board used is 0x00044201.

Second, about EADC

　　 NUC442/NUC472 series includes a 12-bit successive approximation analog-to-digital converter (SAR A/ D converter). The A/D converter can be triggered by software trigger, PWM trigger, timer0~3 overflow pulse trigger, ADINT0, ADINT1 interrupt EOC (conversion end) pulse trigger, and external pin (STADC) input signal to trigger conversion.

3. Module code implementation

　　 This time I quoted library functions and sorted out the usage in detail.

　　(1) First is the initialization function of ADC1, the code is as follows:

 1 void ADC1_Init(void)

 2 {

 3 unsigned char i=0;

 4  SYS_UnlockReg();

 5 CLK_EnableModuleClock(EADC_MODULE); //Enable EADC clock

 6 CLK_SetModuleClock(EADC_MODULE, CLK_CLKSEL1_ADCSEL_PCLK, CLK_CLKDIV0_ADC(5));

 7 //PE8~PE15 ADC1->Channel 0~7

 8 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE8MFP_Msk) | SYS_GPE_MFPH_PE8MFP_ADC1_0;

 9 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE9MFP_Msk) | SYS_GPE_MFPH_PE9MFP_ADC1_1;

10 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE10MFP_Msk) | SYS_GPE_MFPH_PE10MFP_ADC1_2;

11 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE11MFP_Msk) | SYS_GPE_MFPH_PE11MFP_ADC1_3;

12 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE12MFP_Msk) | SYS_GPE_MFPH_PE12MFP_ADC1_4;

13 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE13MFP_Msk) | SYS_GPE_MFPH_PE13MFP_ADC1_5;

14 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE14MFP_Msk) | SYS_GPE_MFPH_PE14MFP_ADC1_6;

15 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE15MFP_Msk) | SYS_GPE_MFPH_PE15MFP_ADC1_7;

16 PE->DINOFF = PE->DINOFF | (GPIO_DINOFF_DINOFF8_Msk | GPIO_DINOFF_DINOFF9_Msk | GPIO_DINOFF_DINOFF10_Msk |

17 GPIO_DINOFF_DINOFF11_Msk | GPIO_DINOFF_DINOFF12_Msk | GPIO_DINOFF_DINOFF13_Msk |

18 GPIO_DINOFF_DINOFF14_Msk | GPIO_DINOFF_DINOFF15_Msk); //Close PE8~15 digital input channel

19

20 SYS->VREFCTL = SYS_VREFCTL_VREF_AVDD; //Set the reference voltage to VDD

21  SYS_LockReg();

22 //--------------------------------------------- ------------------------------------- 

23 /* Enable the A/D converter */

24 EADC_Open(EADC,0); //EADC enable;

25 /* Configure the EADC1 sample module 0~7 for analog input channel 0~7 and software trigger source.*/

26  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE0, EADC_SOFTWARE_TRIGGER, EADC1_CH0);

27  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE1, EADC_SOFTWARE_TRIGGER, EADC1_CH1);

28  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE2, EADC_SOFTWARE_TRIGGER, EADC1_CH2);

29  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE3, EADC_SOFTWARE_TRIGGER, EADC1_CH3);

30  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE4, EADC_SOFTWARE_TRIGGER, EADC1_CH4);

31  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE5, EADC_SOFTWARE_TRIGGER, EADC1_CH5);

32  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE6, EADC_SOFTWARE_TRIGGER, EADC1_CH6);

33  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE7, EADC_SOFTWARE_TRIGGER, EADC1_CH7);

34

35 EADC_CLR_INT_FLAG(EADC, 0x02); //ADINT1 interrupt flag is cleared to 0

36 EADC_ENABLE_INT(EADC, 0x02); //Enable ADINT1

37 for(i=8;i<16;i++) //< span style="color: #008000;">AD1SPIE0:AD1SPIE7=[8:15]

38  {

39 EADC_ENABLE_SAMPLE_MODULE_INT(EADC, 1, 1<//ADC Interrupt 1 source enable; ADC1-SAMPLE10~17 interrupt enable; 

40 }

41  NVIC_EnableIRQ(EADC1_IRQn);

42 }

(2) Then there is the interrupt service function, as follows:< /p>

1 void EADC1_IRQHandler( void) //EADC1 interrupt Service function

2 {

3 EADC1_ConversionFlag = 1;

4 EADC_CLR_INT_FLAG(EADC, 0x02); //Clear the interrupt flag

5 }

(4) Since ADC1 is used, it also needs to be configured as EADC;< /p>

 1 void ADC_Select(ADC_Source source)

 2 {

 3  SYS_UnlockReg();

 4 if(source == ADC1_Select) //Select EADC1

 5  {

 6 /* Set to EADC mode */

 7 SYS->VREFCTL = (SYS->VREFCTL & ~SYS_VREFCTL_ADCMODESEL_EADC) | SYS_VREFCTL_ADCMODESEL_EADC;

 8 }

 9 else //Select ADC0

10  {

11 SYS->VREFCTL = (SYS->VREFCTL & ~SYS_VREFCTL_ADCMODESEL_EADC) | SYS_VREFCTL_ADCMODESEL_ADC;

12 }

13  SYS_LockReg();

14 }

(5) Finally, you can write your own ADC processing function ;

1 unsigned int ADC1_Conversion_Process(ADC1_Channel ch) //EADC1 conversion processing

2 {

3 unsigned int EADC1_Conversion_Result;

4 EADC_START_CONV(EADC,1<<(ch+ 8)); // Start converting module 10~17

5 while(!EADC1_ConversionFlag); //Wait for the conversion to complete

6 EADC1_ConversionFlag = 0;

7 EADC1_Conversion_Result=EADC1_GET_CONV_DATA(EADC,ch); //Read the conversion result;

8 return EADC1_Conversion_Result;

9 }

(6) Finally put the header file;

 1 #ifndef _MY_EADC_H

 2 #define _MY_EADC_H

 3 #include "NUC472_442.h"

 4 //------------------------------------------------- ---------------------

 5 #define ADC1_VREF 3300

 6 #define ADC0_VREF 3300

 7 //------------------------------------------------- ---------------------

 8 typedef enum _ADC1_Channel{ADC1_CH0,ADC1_CH1,ADC1_CH2,ADC1_CH3,ADC1_CH4,ADC1_CH5,ADC1_CH6,ADC1_CH7}ADC1_Channel;

 9 typedef enum _ADC_Source{ADC0_Select,ADC1_Select}ADC_Source;

10 //--------------------------------------------- -------------------------

11 void ADC1_Init(void);

12 unsigned int ADC1_Conversion_Process(ADC1_Channel ch);

13 void ADC_Select(ADC_Source source);

14 //--------------------------------------------- -------------------------

15 extern unsigned char EADC1_ConversionFlag;

16 //--------------------------------------------- -------------------------

17 #endif

(7) This time the software trigger conversion is used, of course, other trigger methods can also be used;

(8) In summary, the use of NUC442 is a bit simpler than STM32, and the functions are also compared. powerful.

 1 void ADC1_Init( void)

 2 {

 3 unsigned char i=0;

 4  SYS_UnlockReg();

 5 CLK_EnableModuleClock(EADC_MODULE); //Enable EADC clock

 6 CLK_SetModuleClock(EADC_MODULE, CLK_CLKSEL1_ADCSEL_PCLK, CLK_CLKDIV0_ADC(5));

 7 //PE8~PE15 ADC1->Channel 0~7

 8 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE8MFP_Msk) | SYS_GPE_MFPH_PE8MFP_ADC1_0;

 9 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE9MFP_Msk) | SYS_GPE_MFPH_PE9MFP_ADC1_1;

10 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE10MFP_Msk) | SYS_GPE_MFPH_PE10MFP_ADC1_2;

11 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE11MFP_Msk) | SYS_GPE_MFPH_PE11MFP_ADC1_3;

12 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE12MFP_Msk) | SYS_GPE_MFPH_PE12MFP_ADC1_4;

13 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE13MFP_Msk) | SYS_GPE_MFPH_PE13MFP_ADC1_5;

14 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE14MFP_Msk) | SYS_GPE_MFPH_PE14MFP_ADC1_6;

15 SYS->GPE_MFPH = (SYS->GPE_MFPH & ~SYS_GPE_MFPH_PE15MFP_Msk) | SYS_GPE_MFPH_PE15MFP_ADC1_7;

16 PE->DINOFF = PE->DINOFF | (GPIO_DINOFF_DINOFF8_Msk | GPIO_DINOFF_DINOFF9_Msk | GPIO_DINOFF_DINOFF10_Msk |

17 GPIO_DINOFF_DINOFF11_Msk | GPIO_DINOFF_DINOFF12_Msk | GPIO_DINOFF_DINOFF13_Msk |

18 GPIO_DINOFF_DINOFF14_Msk | GPIO_DINOFF_DINOFF15_Msk); //Close PE8~15 digital input channel

19

20 SYS->VREFCTL = SYS_VREFCTL_VREF_AVDD; //Set the reference voltage to VDD

21  SYS_LockReg();

22 //--------------------------------------------- ------------------------------------- 

23 /* Enable the A/D converter */

24 EADC_Open(EADC,0); //EADC enable;

25 /* Configure the EADC1 sample module 0~7 for analog input channel 0~7 and software trigger source.*/

26  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE0, EADC_SOFTWARE_TRIGGER, EADC1_CH0);

27  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE1, EADC_SOFTWARE_TRIGGER, EADC1_CH1);

28  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE2, EADC_SOFTWARE_TRIGGER, EADC1_CH2);

29  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE3, EADC_SOFTWARE_TRIGGER, EADC1_CH3);

30  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE4, EADC_SOFTWARE_TRIGGER, EADC1_CH4);

31  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE5, EADC_SOFTWARE_TRIGGER, EADC1_CH5);

32  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE6, EADC_SOFTWARE_TRIGGER, EADC1_CH6);

33  EADC_ConfigSampleModule(EADC, EADC1_SAMPLE_MODULE7, EADC_SOFTWARE_TRIGGER, EADC1_CH7);

34

35 EADC_CLR_INT_FLAG(EADC, 0x02); //ADINT1 interrupt flag is cleared to 0

36 EADC_ENABLE_INT(EADC, 0x02); //Enable ADINT1

37 for(i=8;i<16;i++) //< span style="color: #008000;">AD1SPIE0:AD1SPIE7=[8:15]

38  {

39 EADC_ENABLE_SAMPLE_MODULE_INT(EADC, 1, 1<//ADC Interrupt 1 source enable; ADC1-SAMPLE10~17 interrupt enable; 

40 }

41  NVIC_EnableIRQ(EADC1_IRQn);

42 }

1 void EADC1_IRQHandler(void) //EADC1 interrupt service function

2 {

3 EADC1_ConversionFlag = 1;

4 EADC_CLR_INT_FLAG(EADC, 0x02); //Clear the interrupt flag

5 }

 1< /span> void ADC_Select(ADC_Source source)

 2 {

 3  SYS_UnlockReg();

 4 if(source == ADC1_Select) //Select EADC1

 5  {

 6 /* Set to EADC mode */

 7 SYS->VREFCTL = (SYS->VREFCTL & ~SYS_VREFCTL_ADCMODESEL_EADC) | SYS_VREFCTL_ADCMODESEL_EADC;

 8 }

 9 else //Select ADC0

10  {

11 SYS->VREFCTL = (SYS->VREFCTL & ~SYS_VREFCTL_ADCMODESEL_EADC) | SYS_VREFCTL_ADCMODESEL_ADC;

12 }

13  SYS_LockReg();

14 }

1 unsigned int ADC1_Conversion_Process(ADC1_Channel ch) //EADC1 conversion processing

2 {

3 unsigned int EADC1_Conversion_Result;

4 EADC_START_CONV(EADC,1<<(ch+ 8)); // Start converting module 10~17

5 while(!EADC1_ConversionFlag); //Wait for the conversion to complete

6 EADC1_ConversionFlag = 0;

7 EADC1_Conversion_Result=EADC1_GET_CONV_DATA(EADC,ch); //Read the conversion result;

8 return EADC1_Conversion_Result;

9 }

 1 #ifndef _MY_EADC_H

 2 #define _MY_EADC_H

 3 #include "NUC472_442.h"

 4 //------------------------------------------------- ---------------------

 5 #define ADC1_VREF 3300

 6 #define ADC0_VREF 3300

 7 //------------------------------------------------- ---------------------

 8 typedef enum _ADC1_Channel{ADC1_CH0,ADC1_CH1,ADC1_CH2,ADC1_CH3,ADC1_CH4,ADC1_CH5,ADC1_CH6,ADC1_CH7}ADC1_Channel;

 9 typedef enum _ADC_Source{ADC0_Select,ADC1_Select}ADC_Source;

10 //--------------------------------------------- -------------------------

11 void ADC1_Init(void);

12 unsigned int ADC1_Conversion_Process(ADC1_Channel ch);

13 void ADC_Select(ADC_Source source);

14 //--------------------------------------------- -------------------------

15 extern unsigned char EADC1_ConversionFlag;

16 //--------------------------------------------- -------------------------

17 #endif