学习KEA之ADC之三：中断方式

迷南。 2023-02-21 04:52 14阅读 0赞

> 作者：曾Jerry 或 大橙员, 250359225@qq.com

[学习KEA之ADC之一：基本介绍][KEA_ADC]  
[学习KEA之ADC之二：查询方式][KEA_ADC 1]  
[学习KEA之ADC之三：中断方式][KEA_ADC 2]  
[学习KEA之ADC之四：FIFO][KEA_ADC_FIFO]

**需求：**

*  读取AD7(PTB3), 并转换成 mV, 范围是0 - 5000mV，输入电压大概是2.157V
 *  基本配置：时钟来自bus\_clock, 20MHz, 连续模式， Software trigger，12-bit mode operation，中断

**例程：**

#include "derivative.h" /* include peripheral declarations SSKEAZN64M2 */
    
    void Clk_Init(void);
    void Enable_Interrupt(uint8_t vector_number);
    void init_ADC(void);
    uint32_t ADC_Read(uint8_t channel);
    
    uint32_t adcResultInMv7 = 0;
    
    int main(void)
    { 
    	Clk_Init();
    	init_ADC();
    	Enable_Interrupt(ADC0_IRQn);
    	
    	for(;;)
    	{ 
    
    	}
    
    	return 0;
    }
    
    
    /*********************************************************************************************** * * @brief CLK_Init - Initialize Core Clock to 40MHz, Bus Clock to 20MHz * @param none * @return none * ************************************************************************************************/
    void Clk_Init(void)
    { 
    	ICS_C1|= ICS_C1_IRCLKEN_MASK; /* Enable the internal reference clock*/
    	ICS_C3 = 0x50; /* Reference clock frequency = 31.25 kHz*/
    
    	while(!(ICS_S & ICS_S_LOCK_MASK)); /* Wait for PLL lock, now running at 40 MHz (1024*39.0625 kHz) */
    
    	ICS_C2 |= ICS_C2_BDIV(1) ; /* BDIV=b001, Bus clock = 20 MHz*/
    	ICS_S |= ICS_S_LOCK_MASK ; /* Clear Loss of lock sticky bit */
    }
    
    /*********************************************************************************************** * * @brief Enable_Interrupt(uint8_t vector_number). Enable interrupts from desired module. * @param Module interrupt number from the interrupts vector table * @return none * ************************************************************************************************/
    void Enable_Interrupt(uint8_t vector_number)
    { 
    	NVIC_ClearPendingIRQ(vector_number); 		/* Clear pending interrupt register */
    	NVIC_EnableIRQ(vector_number); 				/* Enable required Interrupt */
    }
    
    void init_ADC(void)
    { 
    	SIM_SCGC |= SIM_SCGC_ADC_MASK; /* Enable bus clock in ADC*/
    	ADC_SC3 |= ADC_SC3_ADICLK(0b00); /* Bus clock selected, 20 MHz*/
    	ADC_SC2 |= 0x00; /* Software Conversion trigger, disable compare function*/
    	ADC_SC2 |= ADC_SC2_REFSEL(0b01); /* Select VDD and VSS as voltage reference source*/
    	ADC_SC1 = 0 ; /* Enable ADC by setting ADCH bits as low*/
    	ADC_SC1 |= ADC_SC1_ADCO_MASK;  /* Continuous mode operation */
    	ADC_SC1 |= ADC_SC1_AIEN_MASK;  /* ADC Interrupt Enabled */
    	ADC_APCTL1 |= ADC_APCTL1_ADPC(1<<7); /* Channel selection */
    	ADC_SC3 |= ADC_SC3_MODE(0b10); /* 12-bit mode operation */
    }
    
    
    /*********************************************************************************************** * * @brief ADC_Read - Read the selected ADC channel * @param ch - channel to read * @return result * ************************************************************************************************/
    uint32_t ADC_Read(uint8_t channel)
    { 
    	ADC_SC1 |= ADC_SC1_ADCH(channel);			/* Select channel to read */
    
    	while(!(ADC_SC1 & ADC_SC1_COCO_MASK));		/* Wait conversion to complete */
    
    	return (uint32_t) ((5000*ADC_R)/0xFFF);     /* Convert result to mv for 0-5V range */
    
    }
    
    
    /*********************************************************************************************** * * @brief ADC0_IRQHandler - Interrupt for ADC channels, Calls user function. * @param none * @return none * ************************************************************************************************/
    void ADC0_IRQHandler()
    { 
    	adcResultInMv7 = ADC_Read(7);
    }

仿真结果如下：  
![在这里插入图片描述][20200628165612280.png]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY_size_16_color_FFFFFF_t_70]

[KEA_ADC]: https://blog.csdn.net/feimeng116/article/details/106949471
[KEA_ADC 1]: https://blog.csdn.net/feimeng116/article/details/106998567
[KEA_ADC 2]: https://blog.csdn.net/feimeng116/article/details/107003190
[KEA_ADC_FIFO]: https://blog.csdn.net/feimeng116/article/details/107037460
[20200628165612280.png]: https://img-blog.csdnimg.cn/20200628165612280.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200702205236938.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY=,size_16,color_FFFFFF,t_70