nrf51822 --- 模拟比较器

来源：互联网发布：C语言最短路径算法编辑：程序博客网时间：2024/06/05 19:43

1.目的

学习nrf51822模拟比较器

2.分析

模拟比较器，用于比较2个模拟信号的大小，

3.平台：

协议栈版本：SDK10.0.0

编译软件：keil 5.14

硬件平台：nrf51822最小系统

例子：SDK 10.0.0\examples\ble_peripheral\ble_app_uart\pca10028\s110\arm4

4.步骤

1.把SDK10.0\components\drivers_nrf\lpcomp 文件中的.c文件添加到目录如下，并添加对应的路径。

2.添加如下代码。

static void lpcomp_event_handler(nrf_lpcomp_event_t event)：设置回调函数

void lpcomp_init(void)初始化比较器。比较器底层配置使用的使系统默认的。

if (p_config == NULL)
{
p_config = &m_default_config;
}

底层硬件配置：nrf_lpcomp_configure(&(p_config->hal) );

/** LPCOMP driver default configuration, including the LPCOMP HAL configuration. */#define NRF_DRV_LPCONF_DEFAULT_CONFIG                                              \    {                                                                              \        .hal                = {LPCOMP_CONFIG_REFERENCE , LPCOMP_CONFIG_DETECTION}, \        .input              = LPCOMP_CONFIG_INPUT,                                 \        .interrupt_priority = LPCOMP_CONFIG_IRQ_PRIORITY                           \    }

这里设置设置参数有: =｛参考电压，检测方式｝
配置对比的输入管脚，

中断优先级

/* LPCOMP */#define LPCOMP_ENABLED 1#if (LPCOMP_ENABLED == 1)#define LPCOMP_CONFIG_REFERENCE    NRF_LPCOMP_REF_SUPPLY_4_8#define LPCOMP_CONFIG_DETECTION    NRF_LPCOMP_DETECT_DOWN#define LPCOMP_CONFIG_IRQ_PRIORITY APP_IRQ_PRIORITY_LOW#define LPCOMP_CONFIG_INPUT        NRF_LPCOMP_INPUT_2#endif

/** * @enum nrf_lpcomp_ref_t * @brief LPCOMP reference selection. */typedef enum{#ifdef NRF51    NRF_LPCOMP_REF_SUPPLY_1_8   = LPCOMP_REFSEL_REFSEL_SupplyOneEighthPrescaling,    /**< Use supply with a 1/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_2_8   = LPCOMP_REFSEL_REFSEL_SupplyTwoEighthsPrescaling,   /**< Use supply with a 2/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_3_8   = LPCOMP_REFSEL_REFSEL_SupplyThreeEighthsPrescaling, /**< Use supply with a 3/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_4_8   = LPCOMP_REFSEL_REFSEL_SupplyFourEighthsPrescaling,  /**< Use supply with a 4/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_5_8   = LPCOMP_REFSEL_REFSEL_SupplyFiveEighthsPrescaling,  /**< Use supply with a 5/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_6_8   = LPCOMP_REFSEL_REFSEL_SupplySixEighthsPrescaling,   /**< Use supply with a 6/8 prescaler as reference. */  NRF_LPCOMP_REF_SUPPLY_7_8   = LPCOMP_REFSEL_REFSEL_SupplySevenEighthsPrescaling, /**< Use supply with a 7/8 prescaler as reference. */#elif defined NRF52    NRF_LPCOMP_REF_SUPPLY_1_8   = LPCOMP_REFSEL_REFSEL_Ref1_8Vdd, /**< Use supply with a 1/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_2_8   = LPCOMP_REFSEL_REFSEL_Ref2_8Vdd, /**< Use supply with a 2/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_3_8   = LPCOMP_REFSEL_REFSEL_Ref3_8Vdd, /**< Use supply with a 3/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_4_8   = LPCOMP_REFSEL_REFSEL_Ref4_8Vdd, /**< Use supply with a 4/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_5_8   = LPCOMP_REFSEL_REFSEL_Ref5_8Vdd, /**< Use supply with a 5/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_6_8   = LPCOMP_REFSEL_REFSEL_Ref6_8Vdd, /**< Use supply with a 6/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_7_8   = LPCOMP_REFSEL_REFSEL_Ref7_8Vdd, /**< Use supply with a 7/8 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_1_16  = LPCOMP_REFSEL_REFSEL_Ref1_16Vdd, /**< Use supply with a 1/16 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_3_16  = LPCOMP_REFSEL_REFSEL_Ref1_16Vdd, /**< Use supply with a 3/16 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_5_16  = LPCOMP_REFSEL_REFSEL_Ref1_16Vdd, /**< Use supply with a 5/16 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_7_16  = LPCOMP_REFSEL_REFSEL_Ref1_16Vdd, /**< Use supply with a 7/16 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_9_16  = LPCOMP_REFSEL_REFSEL_Ref1_16Vdd, /**< Use supply with a 9/16 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_11_16 = LPCOMP_REFSEL_REFSEL_Ref1_16Vdd, /**< Use supply with a 11/16 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_13_16 = LPCOMP_REFSEL_REFSEL_Ref1_16Vdd, /**< Use supply with a 13/16 prescaler as reference. */    NRF_LPCOMP_REF_SUPPLY_15_16 = LPCOMP_REFSEL_REFSEL_Ref1_16Vdd, /**< Use supply with a 15/16 prescaler as reference. */#endif    NRF_LPCOMP_REF_EXT_REF0        = LPCOMP_REFSEL_REFSEL_ARef |                       (LPCOMP_EXTREFSEL_EXTREFSEL_AnalogReference0 << 16), /**< External reference 0. */    NRF_LPCOMP_CONFIG_REF_EXT_REF1 = LPCOMP_REFSEL_REFSEL_ARef |                        (LPCOMP_EXTREFSEL_EXTREFSEL_AnalogReference1 << 16), /**< External reference 1. */} nrf_lpcomp_ref_t;

/** * @enum nrf_lpcomp_input_t * @brief LPCOMP input selection. */typedef enum{    NRF_LPCOMP_INPUT_0 = LPCOMP_PSEL_PSEL_AnalogInput0, /**< Input 0. */    NRF_LPCOMP_INPUT_1 = LPCOMP_PSEL_PSEL_AnalogInput1, /**< Input 1. */    NRF_LPCOMP_INPUT_2 = LPCOMP_PSEL_PSEL_AnalogInput2, /**< Input 2. */    NRF_LPCOMP_INPUT_3 = LPCOMP_PSEL_PSEL_AnalogInput3, /**< Input 3. */    NRF_LPCOMP_INPUT_4 = LPCOMP_PSEL_PSEL_AnalogInput4, /**< Input 4. */    NRF_LPCOMP_INPUT_5 = LPCOMP_PSEL_PSEL_AnalogInput5, /**< Input 5. */    NRF_LPCOMP_INPUT_6 = LPCOMP_PSEL_PSEL_AnalogInput6, /**< Input 6. */    NRF_LPCOMP_INPUT_7 = LPCOMP_PSEL_PSEL_AnalogInput7  /**< Input 7. */} nrf_lpcomp_input_t;

/** * @enum nrf_lpcomp_detect_t * @brief LPCOMP detection type selection. */typedef enum{    NRF_LPCOMP_DETECT_CROSS = LPCOMP_ANADETECT_ANADETECT_Cross, /**< Generate ANADETEC on crossing, both upwards and downwards crossing. */    NRF_LPCOMP_DETECT_UP    = LPCOMP_ANADETECT_ANADETECT_Up,    /**< Generate ANADETEC on upwards crossing only. */    NRF_LPCOMP_DETECT_DOWN  = LPCOMP_ANADETECT_ANADETECT_Down   /**< Generate ANADETEC on downwards crossing only. */} nrf_lpcomp_detect_t;

这里选择的是：电源电压的4/8 作为参考，
输入电压低于参考电压的时候，产生事件NRF_LPCOMP_EVENT_DOWN
中断优先级为低

模拟输入通道2作为模拟比较电压。

具体参考手册：nRF51_Series_Reference_manual v3.0 和 nRF51822_PS v3.1

下载地址：http://www.nordicsemi.com/eng/Products/Bluetooth-Smart-Bluetooth-low-energy/nRF51822

/**@brief Function for placing the application in low power state while waiting for events. */ void lpcomp_event_handler(nrf_lpcomp_event_t event){    if (event == NRF_LPCOMP_EVENT_READY)    {     SEGGER_RTT_printf(0,"\r\nNRF_LPCOMP_EVENT_READY\r\n");    }  if (event == NRF_LPCOMP_EVENT_DOWN)    {     SEGGER_RTT_printf(0,"\r\nNRF_LPCOMP_EVENT_DOWN\r\n");    }  if (event == NRF_LPCOMP_EVENT_UP)    {     SEGGER_RTT_printf(0,"\r\nNRF_LPCOMP_EVENT_UP\r\n");    }}

/** * @brief Initialize LPCOMP driver. */void lpcomp_init(void){    uint32_t                err_code;    // initialize LPCOMP driver, from this point LPCOMP will be active and provided    // event handler will be executed when defined action is detected    err_code = nrf_drv_lpcomp_init(NULL, lpcomp_event_handler);    APP_ERROR_CHECK(err_code);    nrf_drv_lpcomp_enable();}

ret_code_t nrf_drv_lpcomp_init(const nrf_drv_lpcomp_config_t * p_config,                               lpcomp_events_handler_t   events_handler){    if (m_state != NRF_DRV_STATE_UNINITIALIZED)    { // LPCOMP driver is already initialized        return NRF_ERROR_INVALID_STATE;    }    if (p_config == NULL)    {        p_config = &m_default_config;    }    nrf_lpcomp_configure(&(p_config->hal) );    if (events_handler)    {        m_lpcomp_events_handler = events_handler;    }    else    {        return NRF_ERROR_INVALID_PARAM;    }    nrf_lpcomp_input_select(p_config->input);    switch (p_config->hal.detection)    {        case NRF_LPCOMP_DETECT_UP:            nrf_lpcomp_int_enable(LPCOMP_INTENSET_UP_Msk);            break;        case NRF_LPCOMP_DETECT_DOWN:            nrf_lpcomp_int_enable(LPCOMP_INTENSET_DOWN_Msk);            break;        case NRF_LPCOMP_DETECT_CROSS:            nrf_lpcomp_int_enable(LPCOMP_INTENSET_CROSS_Msk);            break;        default:            break;    }    nrf_lpcomp_shorts_enable(NRF_LPCOMP_SHORT_READY_SAMPLE_MASK);    nrf_drv_common_irq_enable(LPCOMP_IRQn, p_config->interrupt_priority);    m_state = NRF_DRV_STATE_INITIALIZED;    return NRF_SUCCESS;}

这个是，中断函数，会查找对应的标志位，并产生对应的回调。。

void LPCOMP_IRQHandler(void){    lpcomp_execute_handler(NRF_LPCOMP_EVENT_READY, LPCOMP_INTENSET_READY_Msk);    lpcomp_execute_handler(NRF_LPCOMP_EVENT_DOWN, LPCOMP_INTENSET_DOWN_Msk);    lpcomp_execute_handler(NRF_LPCOMP_EVENT_UP, LPCOMP_INTENSET_UP_Msk);    lpcomp_execute_handler(NRF_LPCOMP_EVENT_CROSS, LPCOMP_INTENSET_CROSS_Msk);}

4.实验，把P02脚短接到地的时候：与配置，和回调函数一样。ok ye！！！

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