S32K144 EVB之ADC

来源：互联网发布：硬盘文件恢复软件编辑：程序博客网时间：2024/06/07 06:07

开发环境

IAR7.8 + S32K144-EVB

关于ADC的使用，参考了AN5413.pdf中的例程

首先是ADC初始化，使用PTC14和RGB灯相关引脚：

void ADC_init(void){        PCC->PCCn[PCC_ADC0_INDEX] &=~ PCC_PCCn_CGC_MASK; /* Disable clock to change PCS */        PCC->PCCn[PCC_ADC0_INDEX] |= PCC_PCCn_PCS(1); /* PCS=1: Select SOSCDIV2 */        PCC->PCCn[PCC_ADC0_INDEX] |= PCC_PCCn_CGC_MASK; /* Enable bus clock in ADC */        ADC0->SC1[0] = 0x0000003F;        /* ADCH=3F: Module is disabled for conversions*/        /* AIEN=0: Interrupts are disabled */        ADC0->CFG1 = 0x000000004;        /* ADICLK=0: Input clk=ALTCLK1=SOSCDIV2 */        /* ADIV=0: Prescaler=1 */        /* MODE=1: 12-bit conversion */        ADC0->CFG2 = 0x00000000C;        /* SMPLTS=12(default): sample time is 13 ADC clks */        ADC0->SC2 = 0x00000000;        /* ADTRG=0: SW trigger */        /* ACFE,ACFGT,ACREN=0: Compare func disabled */        /* DMAEN=0: DMA disabled */        /* REFSEL=0: Voltage reference pins= VREFH, VREEFL */        ADC0->SC3 = 0x00000000;        /* CAL=0: Do not start calibration sequence */        /* ADCO=0: One conversion performed */        /* AVGE,AVGS=0: HW average function disabled */}

然后是ADC相关函数:

void convertAdcChan(u16 adcChan){        /* For SW trigger mode, SC1[0] is used */        ADC0->SC1[0]&=~ADC_SC1_ADCH_MASK; /* Clear prior ADCH bits */        ADC0->SC1[0] = ADC_SC1_ADCH(adcChan); /* Initiate Conversion*/}u8 adc_complete(void){        return ((ADC0->SC1[0] & ADC_SC1_COCO_MASK)>>ADC_SC1_COCO_SHIFT); /* Wait for completion */}u32 read_adc_chx(void){        u16 adc_result=0;        adc_result = ADC0->R[0]; /* For SW trigger mode, R[0] is used */        return (u32) ((5000*adc_result)/0xFFF); /* Convert result to mv for 0-5V range */}

全部示例代码如下：

#include "S32K144.h"#include "S32K144_features.h"#include "fsl_core_cm4.h"#define BIT(n)          (1 << (n))#define UNUSED(x)       ((void)(x))#define do_nothing()    {static u32 cnt = 0;cnt ++;}#define ARRAY_SIZE(x)   (sizeof(x)/sizeof(x[0]))typedef unsigned char   u8;typedef unsigned short  u16;typedef unsigned long   u32;#define RED     15#define GREEN   16#define BLUE    0void SOSC_init_8MHz(void);void SPLL_init_160MHz(void);void NormalRUNmode_80MHz(void);void PORT_init(void);void LED_light(u8 color);void ADC_init(void);void convertAdcChan(u16 adcChan);u8 adc_complete(void);u32 read_adc_chx(void);u8 color = 0;u32 adcResultInMv = 0;int main(void){        SOSC_init_8MHz(); /* Initialize system oscillator for 8 MHz xtal */        SPLL_init_160MHz(); /* Initialize SPLL to 160 MHz with 8 MHz SOSC */        NormalRUNmode_80MHz(); /* Init clocks: 80 MHz SPLL & core, 40 MHz bus, 20 MHz flash */        PORT_init(); /* Init port clocks and gpio outputs */        ADC_init(); /* Init ADC resolution 12 bit*/        for(;;) {                //PTC14                convertAdcChan(12); /* Convert Channel AD12 to pot on EVB */                while(adc_complete()==0){} /* Wait for conversion complete flag */                adcResultInMv = read_adc_chx(); /* Get channel's conversion results in mv */                color = adcResultInMv / 625;                if (adcResultInMv == 5000)                        color --;                LED_light(color);                //011101b - VREFSH is selected as input. Voltage reference selected is determined by SC2[REFSEL].                convertAdcChan(29); /* Convert chan 29, Vrefsh */                while(adc_complete()==0){} /* Wait for conversion complete flag */                adcResultInMv = read_adc_chx(); /* Get channel's conversion results in mv */        }}void SOSC_init_8MHz(void){        SCG->SOSCDIV = 0x00000101; /* SOSCDIV1 & SOSCDIV2 =1: divide by 1 */        SCG->SOSCCFG = 0x00000024; /* Range=2: Medium freq (SOSC between 1MHz-8MHz)*/        /* HGO=0: Config xtal osc for low power */        /* EREFS=1: Input is external XTAL */        while(SCG->SOSCCSR & SCG_SOSCCSR_LK_MASK); /* Ensure SOSCCSR unlocked */        SCG->SOSCCSR = 0x00000001; /* LK=0: SOSCCSR can be written */        /* SOSCCMRE=0: OSC CLK monitor IRQ if enabled */        /* SOSCCM=0: OSC CLK monitor disabled */        /* SOSCERCLKEN=0: Sys OSC 3V ERCLK output clk disabled */        /* SOSCLPEN=0: Sys OSC disabled in VLP modes */        /* SOSCSTEN=0: Sys OSC disabled in Stop modes */        /* SOSCEN=1: Enable oscillator */        while(!(SCG->SOSCCSR & SCG_SOSCCSR_SOSCVLD_MASK)); /* Wait for sys OSC clk valid */}void SPLL_init_160MHz(void){        while(SCG->SPLLCSR & SCG_SPLLCSR_LK_MASK); /* Ensure SPLLCSR unlocked */        SCG->SPLLCSR = 0x00000000; /* SPLLEN=0: SPLL is disabled (default) */        SCG->SPLLDIV = 0x00000302; /* SPLLDIV1 divide by 2; SPLLDIV2 divide by 4 */        SCG->SPLLCFG = 0x00180000; /* PREDIV=0: Divide SOSC_CLK by 0+1=1 */        /* MULT=24: Multiply sys pll by 4+24=40 */        /* SPLL_CLK = 8MHz / 1 * 40 / 2 = 160 MHz */        while(SCG->SPLLCSR & SCG_SPLLCSR_LK_MASK); /* Ensure SPLLCSR unlocked */        SCG->SPLLCSR = 0x00000001; /* LK=0: SPLLCSR can be written */        /* SPLLCMRE=0: SPLL CLK monitor IRQ if enabled */        /* SPLLCM=0: SPLL CLK monitor disabled */        /* SPLLSTEN=0: SPLL disabled in Stop modes */        /* SPLLEN=1: Enable SPLL */        while(!(SCG->SPLLCSR & SCG_SPLLCSR_SPLLVLD_MASK)); /* Wait for SPLL valid */}void NormalRUNmode_80MHz(void){        /* Change to normal RUN mode with 8MHz SOSC, 80 MHz PLL*/        SCG->RCCR = SCG_RCCR_SCS(6) | SCG_RCCR_DIVCORE(1) | SCG_RCCR_DIVBUS(1) | SCG_RCCR_DIVSLOW(2);        /* PLL as clock source*/        /* DIVCORE=1, div. by 2: Core clock = 160/2 MHz = 80 MHz*/        /* DIVBUS=1, div. by 2: bus clock = 40 MHz*/        /* DIVSLOW=2, div. by 3: SCG slow, flash clock= 26 2/3 MHz*/        while (((SCG->CSR & SCG_CSR_SCS_MASK) >> SCG_CSR_SCS_SHIFT ) != 6) {}        /* Wait for sys clk src = SPLL */}void PORT_init (void){        PCC->PCCn[PCC_PORTD_INDEX ]|=PCC_PCCn_CGC_MASK; /* Enable clock for PORTD */        PORTD->PCR[RED  ] = 0x00000100; /* Port D0: MUX = GPIO */        PORTD->PCR[GREEN] = 0x00000100; /* Port D15: MUX = GPIO */        PORTD->PCR[BLUE ] = 0x00000100; /* Port D16: MUX = GPIO */        PTD->PDDR |= BIT(RED  ); /* Port D0: Data Direction= output */        PTD->PDDR |= BIT(GREEN); /* Port D15: Data Direction= output */        PTD->PDDR |= BIT(BLUE ); /* Port D16: Data Direction= output */}void LED_light(u8 color){        PTD->PSOR |= BIT(RED) | BIT(GREEN) | BIT(BLUE);        if (color & 0x01)                PTD->PCOR |= BIT(RED);        if (color & 0x02)                PTD->PCOR |= BIT(GREEN);        if (color & 0x04)                PTD->PCOR |= BIT(BLUE);}void ADC_init(void){        PCC->PCCn[PCC_ADC0_INDEX] &=~ PCC_PCCn_CGC_MASK; /* Disable clock to change PCS */        PCC->PCCn[PCC_ADC0_INDEX] |= PCC_PCCn_PCS(1); /* PCS=1: Select SOSCDIV2 */        PCC->PCCn[PCC_ADC0_INDEX] |= PCC_PCCn_CGC_MASK; /* Enable bus clock in ADC */        ADC0->SC1[0] = 0x0000003F;        /* ADCH=3F: Module is disabled for conversions*/        /* AIEN=0: Interrupts are disabled */        ADC0->CFG1 = 0x000000004;        /* ADICLK=0: Input clk=ALTCLK1=SOSCDIV2 */        /* ADIV=0: Prescaler=1 */        /* MODE=1: 12-bit conversion */        ADC0->CFG2 = 0x00000000C;        /* SMPLTS=12(default): sample time is 13 ADC clks */        ADC0->SC2 = 0x00000000;        /* ADTRG=0: SW trigger */        /* ACFE,ACFGT,ACREN=0: Compare func disabled */        /* DMAEN=0: DMA disabled */        /* REFSEL=0: Voltage reference pins= VREFH, VREEFL */        ADC0->SC3 = 0x00000000;        /* CAL=0: Do not start calibration sequence */        /* ADCO=0: One conversion performed */        /* AVGE,AVGS=0: HW average function disabled */}void convertAdcChan(u16 adcChan){        /* For SW trigger mode, SC1[0] is used */        ADC0->SC1[0]&=~ADC_SC1_ADCH_MASK; /* Clear prior ADCH bits */        ADC0->SC1[0] = ADC_SC1_ADCH(adcChan); /* Initiate Conversion*/}u8 adc_complete(void){        return ((ADC0->SC1[0] & ADC_SC1_COCO_MASK)>>ADC_SC1_COCO_SHIFT); /* Wait for completion */}u32 read_adc_chx(void){        u16 adc_result=0;        adc_result = ADC0->R[0]; /* For SW trigger mode, R[0] is used */        return (u32) ((5000*adc_result)/0xFFF); /* Convert result to mv for 0-5V range */}

编译运行，可以通过调节电位器来改变RGB灯的颜色。

阅读全文

0 0