Pandora IOT development board learning (RT thread) - Experiment 4 buzzer + motor experiment [key external interrupt] (learning notes)

This article code reference RT-Thread official BSP

Experimental function

Routine source code ：（main.c）

Functions realized by this experiment ：4 Keys correspond to different functions （ Control the motor to turn left or right , Control buzzer off ）, among 3 Keys are detected by external interruption （ Another key is detected by polling ）, Most of the operation code is interrupting service （ Callback ） Function , The code of motor control and buzzer control is very simple , Is full of GPIO Write operations , It is not analyzed separately .

/* * Copyright (c) 2006-2018, RT-Thread Development Team * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * 2018-08-23 balanceTWK first implementation */

#include <rtthread.h>
#include <rtdevice.h>
#include <board.h>

#define DBG_TAG "main"
#define DBG_LVL DBG_LOG
#include <rtdbg.h>

enum
{
    
    MOTOR_STOP,
    MOTOR_LEFT,
    MOTOR_RIGHT
};

/*  Motor control  */
void motor_ctrl(rt_uint8_t turn)
{
    
    if (turn == MOTOR_STOP)
    {
    
        rt_pin_write(PIN_MOTOR_A, PIN_LOW);
        rt_pin_write(PIN_MOTOR_B, PIN_LOW);
    }
    else if (turn == MOTOR_LEFT)
    {
    
        rt_pin_write(PIN_MOTOR_A, PIN_LOW);
        rt_pin_write(PIN_MOTOR_B, PIN_HIGH);
    }
    else if (turn == MOTOR_RIGHT)
    {
    
        rt_pin_write(PIN_MOTOR_A, PIN_HIGH);
        rt_pin_write(PIN_MOTOR_B, PIN_LOW);
    }
    else
    {
    
        LOG_D("err parameter ! Please enter 0-2.");
    }
}

void beep_ctrl(rt_uint8_t on)
{
    
    if (on)
    {
    
        rt_pin_write(PIN_BEEP, PIN_HIGH);
    }
    else
    {
    
        rt_pin_write(PIN_BEEP, PIN_LOW);
    }
}

/*  Interrupt callback  */
void irq_callback(void *args)
{
    
    rt_uint32_t sign = (rt_uint32_t)args;
    switch (sign)
    {
    
    case PIN_KEY0:
        motor_ctrl(MOTOR_LEFT);
        LOG_D("KEY0 interrupt. motor turn left.");
        break;
    case PIN_KEY1:
        motor_ctrl(MOTOR_RIGHT);
        LOG_D("KEY1 interrupt. motor turn right.");
        break;
    case PIN_KEY2:
        motor_ctrl(MOTOR_STOP);
        LOG_D("KEY2 interrupt. motor stop.");
        break;
    default:
        LOG_E("error sign= %d !", sign);
        break;
    }
}

int main(void)
{
    
    unsigned int count = 1;

    /*  Set the key pin to the input mode  */
    rt_pin_mode(PIN_KEY0, PIN_MODE_INPUT_PULLUP);
    rt_pin_mode(PIN_KEY1, PIN_MODE_INPUT_PULLUP);
    rt_pin_mode(PIN_KEY2, PIN_MODE_INPUT_PULLUP);
    rt_pin_mode(PIN_WK_UP, PIN_MODE_INPUT_PULLDOWN);

    /*  Set the motor control pin to the input mode  */
    rt_pin_mode(PIN_MOTOR_A, PIN_MODE_OUTPUT);
    rt_pin_mode(PIN_MOTOR_B, PIN_MODE_OUTPUT);

    /*  Set buzzer pin to output mode  */
    rt_pin_mode(PIN_BEEP, PIN_MODE_OUTPUT);

    /*  Set the key interrupt mode and interrupt callback function  */
    rt_pin_attach_irq(PIN_KEY0, PIN_IRQ_MODE_FALLING, irq_callback, (void *)PIN_KEY0);
    rt_pin_attach_irq(PIN_KEY1, PIN_IRQ_MODE_FALLING, irq_callback, (void *)PIN_KEY1);
    rt_pin_attach_irq(PIN_KEY2, PIN_IRQ_MODE_FALLING, irq_callback, (void *)PIN_KEY2);

    /*  To interrupt  */
    rt_pin_irq_enable(PIN_KEY0, PIN_IRQ_ENABLE);
    rt_pin_irq_enable(PIN_KEY1, PIN_IRQ_ENABLE);
    rt_pin_irq_enable(PIN_KEY2, PIN_IRQ_ENABLE);

    while (count > 0)
    {
    
        if (rt_pin_read(PIN_WK_UP) == PIN_HIGH)
        {
    
            rt_thread_mdelay(50);
            if (rt_pin_read(PIN_WK_UP) == PIN_HIGH)
            {
    
                LOG_D("WK_UP pressed. beep on.");
                beep_ctrl(1);
            }
        }
        else
        {
    
            beep_ctrl(0);
        }
        rt_thread_mdelay(10);
        count++;
    }
    return 0;
}

Code analysis

rt_pin_mode()

The function is to GPIO Pin The initialization , Defined as

/* RT-Thread Hardware PIN APIs */
void rt_pin_mode(rt_base_t pin, rt_base_t mode)
{
    
    RT_ASSERT(_hw_pin.ops != RT_NULL);
    _hw_pin.ops->pin_mode(&_hw_pin.parent, pin, mode);
}

Parameters pin It's a rt_base_t Variable （long), Below GET_PIN() yes STM32 Of pin Value macro definition , Fill in capital letters for the first parameter , The second parameter is filled with numbers .

#define GET_PIN(PORTx,PIN) (rt_base_t)((16 * ( ((rt_base_t)__STM32_PORT(PORTx) - (rt_base_t)GPIOA)/(0x0400UL) )) + PIN)

#define __STM32_PORT(port) GPIO##port // ##  Is a character connector , If  port  by  A, said  GPIOA

For example, in the experiment #define PIN_LED_R GET_PIN(E, 7) , Express GPIOE GPIO_Pin7

at present RT-Thread Supported pin operating modes include ：

#define PIN_MODE_OUTPUT 0x00 /*  Output  */
#define PIN_MODE_INPUT 0x01 /*  Input  */
#define PIN_MODE_INPUT_PULLUP 0x02 /*  Pull up input  */
#define PIN_MODE_INPUT_PULLDOWN 0x03 /*  Drop down input  */
#define PIN_MODE_OUTPUT_OD 0x04 /*  Open drain output  */

stay bsp Of drv_gpio.c In file , There is a bottom layer GPIO drive , Here is STM32 Of GPIO Driver function of mode setting （ You should be familiar with , Just use HAL Library written GPIO Initialization code ）

static void stm32_pin_mode(rt_device_t dev, rt_base_t pin, rt_base_t mode)
{
    
    const struct pin_index *index;
    GPIO_InitTypeDef GPIO_InitStruct;

    index = get_pin(pin);
    if (index == RT_NULL)
    {
    
        return;
    }

    /* Configure GPIO_InitStructure */
    GPIO_InitStruct.Pin = index->pin;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;

    if (mode == PIN_MODE_OUTPUT)
    {
    
        /* output setting */
        GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
        GPIO_InitStruct.Pull = GPIO_NOPULL;
    }
    else if (mode == PIN_MODE_INPUT)
    {
    
        /* input setting: not pull. */
        GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
        GPIO_InitStruct.Pull = GPIO_NOPULL;
    }
    else if (mode == PIN_MODE_INPUT_PULLUP)
    {
    
        /* input setting: pull up. */
        GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
        GPIO_InitStruct.Pull = GPIO_PULLUP;
    }
    else if (mode == PIN_MODE_INPUT_PULLDOWN)
    {
    
        /* input setting: pull down. */
        GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
        GPIO_InitStruct.Pull = GPIO_PULLDOWN;
    }
    else if (mode == PIN_MODE_OUTPUT_OD)
    {
    
        /* output setting: od. */
        GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
        GPIO_InitStruct.Pull = GPIO_NOPULL;
    }

    HAL_GPIO_Init(index->gpio, &GPIO_InitStruct);
}

rt_pin_attach_irq()

This is a RT-Thread Break binding （ register ） function , It will call the corresponding functions in the current platform driver .

rt_err_t rt_pin_attach_irq(rt_int32_t pin, rt_uint32_t mode,
                             void (*hdr)(void *args), void  *args)
{
    
    RT_ASSERT(_hw_pin.ops != RT_NULL);
    if(_hw_pin.ops->pin_attach_irq)
    {
    
        return _hw_pin.ops->pin_attach_irq(&_hw_pin.parent, pin, mode, hdr, args);
    }
    return RT_ENOSYS;
}

bsp drive （drv_gpio.c） It defines STM32 Interrupt registration function of stm32_pin_attach_irq()：

static rt_err_t stm32_pin_attach_irq(struct rt_device *device, rt_int32_t pin,
                                     rt_uint32_t mode, void (*hdr)(void *args), void *args)
{
    
    const struct pin_index *index;
    rt_base_t level;
    rt_int32_t irqindex = -1;

    index = get_pin(pin);
    if (index == RT_NULL)
    {
    
        return RT_ENOSYS;
    }
    irqindex = bit2bitno(index->pin);
    if (irqindex < 0 || irqindex >= ITEM_NUM(pin_irq_map))
    {
    
        return RT_ENOSYS;
    }

    level = rt_hw_interrupt_disable();
    if (pin_irq_hdr_tab[irqindex].pin == pin &&
            pin_irq_hdr_tab[irqindex].hdr == hdr &&
            pin_irq_hdr_tab[irqindex].mode == mode &&
            pin_irq_hdr_tab[irqindex].args == args)
    {
    
        rt_hw_interrupt_enable(level);
        return RT_EOK;
    }
    if (pin_irq_hdr_tab[irqindex].pin != -1)
    {
    
        rt_hw_interrupt_enable(level);
        return RT_EBUSY;
    }
    pin_irq_hdr_tab[irqindex].pin = pin;
    pin_irq_hdr_tab[irqindex].hdr = hdr;
    pin_irq_hdr_tab[irqindex].mode = mode;
    pin_irq_hdr_tab[irqindex].args = args;
    rt_hw_interrupt_enable(level);

    return RT_EOK;
}

attach The principle of function is very simple , It is to store the current interrupt information in an interrupt table in the driver code , The structure of the interrupt table is defined as ：

struct rt_pin_irq_hdr
{
    
    rt_int16_t        pin;
    rt_uint16_t       mode;
    void (*hdr)(void *args);  //  Interrupt callback function 
    void             *args;
};

rt_pin_irq_enable()

This is a RT-Thread Kernel pin Interrupt enable function , The actual operation is the platform driven corresponding function ,

rt_err_t rt_pin_irq_enable(rt_base_t pin, rt_uint32_t enabled)
{
    
    RT_ASSERT(_hw_pin.ops != RT_NULL);
    if(_hw_pin.ops->pin_irq_enable)
    {
    
        return _hw_pin.ops->pin_irq_enable(&_hw_pin.parent, pin, enabled);
    }
    return RT_ENOSYS;
}

STM32 The interrupt enabling function in the platform driver is as follows , The amount of code is still very large （HAL Configuration of external interrupts in the Library , Due to the consideration of different parameter options , So it's a lot of code ）：

static rt_err_t stm32_pin_irq_enable(struct rt_device *device, rt_base_t pin,
                                     rt_uint32_t enabled)
{
    
    const struct pin_index *index;
    const struct pin_irq_map *irqmap;
    rt_base_t level;
    rt_int32_t irqindex = -1;
    GPIO_InitTypeDef GPIO_InitStruct;

    index = get_pin(pin);
    if (index == RT_NULL)
    {
    
        return RT_ENOSYS;
    }

    if (enabled == PIN_IRQ_ENABLE)
    {
    
        irqindex = bit2bitno(index->pin);
        if (irqindex < 0 || irqindex >= ITEM_NUM(pin_irq_map))
        {
    
            return RT_ENOSYS;
        }

        level = rt_hw_interrupt_disable();

        if (pin_irq_hdr_tab[irqindex].pin == -1)
        {
    
            rt_hw_interrupt_enable(level);
            return RT_ENOSYS;
        }

        irqmap = &pin_irq_map[irqindex];

        /* Configure GPIO_InitStructure */
        GPIO_InitStruct.Pin = index->pin;        
        GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
        switch (pin_irq_hdr_tab[irqindex].mode)
        {
    
        case PIN_IRQ_MODE_RISING:
            GPIO_InitStruct.Pull = GPIO_PULLDOWN;
            GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
            break;
        case PIN_IRQ_MODE_FALLING:
            GPIO_InitStruct.Pull = GPIO_PULLUP;
            GPIO_InitStruct.Mode = GPIO_MODE_IT_FALLING;
            break;
        case PIN_IRQ_MODE_RISING_FALLING:
            GPIO_InitStruct.Pull = GPIO_NOPULL;
            GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING_FALLING;
            break;
        }
        HAL_GPIO_Init(index->gpio, &GPIO_InitStruct);

        HAL_NVIC_SetPriority(irqmap->irqno, 5, 0);
        HAL_NVIC_EnableIRQ(irqmap->irqno);
        pin_irq_enable_mask |= irqmap->pinbit;

        rt_hw_interrupt_enable(level);
    }
    else if (enabled == PIN_IRQ_DISABLE)
    {
    
        irqmap = get_pin_irq_map(index->pin);
        if (irqmap == RT_NULL)
        {
    
            return RT_ENOSYS;
        }

        level = rt_hw_interrupt_disable();

        HAL_GPIO_DeInit(index->gpio, index->pin);

        pin_irq_enable_mask &= ~irqmap->pinbit;
#if defined(SOC_SERIES_STM32F0) || defined(SOC_SERIES_STM32G0)
        if (( irqmap->pinbit>=GPIO_PIN_0 )&&( irqmap->pinbit<=GPIO_PIN_1 ))
        {
    
            if(!(pin_irq_enable_mask&(GPIO_PIN_0|GPIO_PIN_1)))
            {
        
                HAL_NVIC_DisableIRQ(irqmap->irqno);
            }
        }
        else if (( irqmap->pinbit>=GPIO_PIN_2 )&&( irqmap->pinbit<=GPIO_PIN_3 ))
        {
    
            if(!(pin_irq_enable_mask&(GPIO_PIN_2|GPIO_PIN_3)))
            {
        
                HAL_NVIC_DisableIRQ(irqmap->irqno);
            }
        }
        else if (( irqmap->pinbit>=GPIO_PIN_4 )&&( irqmap->pinbit<=GPIO_PIN_15 ))
        {
    
            if(!(pin_irq_enable_mask&(GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7|GPIO_PIN_8|GPIO_PIN_9|
                                      GPIO_PIN_10|GPIO_PIN_11|GPIO_PIN_12|GPIO_PIN_13|GPIO_PIN_14|GPIO_PIN_15)))
            {
        
                HAL_NVIC_DisableIRQ(irqmap->irqno);
            }
        }    
        else
        {
    
            HAL_NVIC_DisableIRQ(irqmap->irqno);
        }         
#else 
        if (( irqmap->pinbit>=GPIO_PIN_5 )&&( irqmap->pinbit<=GPIO_PIN_9 ))
        {
    
            if(!(pin_irq_enable_mask&(GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7|GPIO_PIN_8|GPIO_PIN_9)))
            {
        
                HAL_NVIC_DisableIRQ(irqmap->irqno);
            }
        }
        else if (( irqmap->pinbit>=GPIO_PIN_10 )&&( irqmap->pinbit<=GPIO_PIN_15 ))
        {
    
            if(!(pin_irq_enable_mask&(GPIO_PIN_10|GPIO_PIN_11|GPIO_PIN_12|GPIO_PIN_13|GPIO_PIN_14|GPIO_PIN_15)))
            {
        
                HAL_NVIC_DisableIRQ(irqmap->irqno);
            }
        }
        else
        {
    
            HAL_NVIC_DisableIRQ(irqmap->irqno);
        }        
#endif 
        rt_hw_interrupt_enable(level);  
    }
    else
    {
    
        return -RT_ENOSYS;
    }

    return RT_EOK;
}

Interrupt handling function

The interrupt handler is already in main.c In the definition of , It's not shown here .

When an external interrupt is triggered , Will trigger HAL Library interrupt function HAL_GPIO_EXTI_Callback(), and STM32 bsp In this function pin_irq_hdr(bit2bitno(GPIO_Pin));, This function will call the corresponding callback function according to the interrupt number assigned during interrupt registration .

HAL_GPIO_EXTI_Callback()

#if defined(SOC_SERIES_STM32G0)
void HAL_GPIO_EXTI_Rising_Callback(uint16_t GPIO_Pin)
{
    
    pin_irq_hdr(bit2bitno(GPIO_Pin));
}

void HAL_GPIO_EXTI_Falling_Callback(uint16_t GPIO_Pin)
{
    
    pin_irq_hdr(bit2bitno(GPIO_Pin));
}
#else
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
    
    pin_irq_hdr(bit2bitno(GPIO_Pin));
}
#endif

pin_irq_hdr()

rt_inline void pin_irq_hdr(int irqno)
{
    
    if (pin_irq_hdr_tab[irqno].hdr)
    {
    
        pin_irq_hdr_tab[irqno].hdr(pin_irq_hdr_tab[irqno].args);
    }
}

rt_pin_read()

GPIO Read function , Here is the definition of the function ：

int  rt_pin_read(rt_base_t pin)
{
    
    RT_ASSERT(_hw_pin.ops != RT_NULL);
    return _hw_pin.ops->pin_read(&_hw_pin.parent, pin);
}

and GPIO The mode configuration function is similar , It will call the corresponding function in the underlying driver , The underlying function is through HAL_GPIO_ReadPin() To get GPIO The level of .

static int stm32_pin_read(rt_device_t dev, rt_base_t pin)
{
    
    int value;
    const struct pin_index *index;

    value = PIN_LOW;

    index = get_pin(pin);
    if (index == RT_NULL)
    {
    
        return value;
    }

    value = HAL_GPIO_ReadPin(index->gpio, index->pin);

    return value;
}

rt_thread_mdelay()

This is a RT-Thread Millisecond delay function , The definition is as follows ：

rt_err_t rt_thread_mdelay(rt_int32_t ms)
{
    
    rt_tick_t tick;

	//  Get the required clock beat 
    tick = rt_tick_from_millisecond(ms);
	
	//  Block the corresponding beat time 
    return rt_thread_sleep(tick);
}

rt_tick_from_millisecond()

/** *  Work out  ms  The number of corresponding clock beats  * * * @param ms the specified millisecond * - Negative Number wait forever * - Zero not wait * - Max 0x7fffffff * * @return the calculated tick */
rt_tick_t rt_tick_from_millisecond(rt_int32_t ms)
{
    
    rt_tick_t tick;

    if (ms < 0)
    {
    
        tick = (rt_tick_t)RT_WAITING_FOREVER;  // -1 
    }
    else
    {
    
    	//  take “ Beats per second ” / 1000 * ms, Calculate the corresponding second beats 
        tick = RT_TICK_PER_SECOND * (ms / 1000);
		
		//  Plus less than  1000ms  Part of the beat number 
        tick += (RT_TICK_PER_SECOND * (ms % 1000) + 999) / 1000;
    }
    
    /* return the calculated tick */
    return tick;
}

rt_thread_sleep()

Thread sleep （ Hang up ） function , The parameter is the number of system beats ：

/** *  This function can make the current thread hang for a period of time （ from  tick  decision ） * * @param tick the sleep ticks * * @return RT_EOK */
rt_err_t rt_thread_sleep(rt_tick_t tick)
{
    
    register rt_base_t temp;
    struct rt_thread *thread;

    /* set to current thread */
    thread = rt_thread_self();
    RT_ASSERT(thread != RT_NULL);
    RT_ASSERT(rt_object_get_type((rt_object_t)thread) == RT_Object_Class_Thread);

    /* disable interrupt */
    temp = rt_hw_interrupt_disable();

    /* suspend thread */
    rt_thread_suspend(thread);

    /* reset the timeout of thread timer and start it */
    rt_timer_control(&(thread->thread_timer), RT_TIMER_CTRL_SET_TIME, &tick);
    rt_timer_start(&(thread->thread_timer));

    /* enable interrupt */
    rt_hw_interrupt_enable(temp);

    rt_schedule();

    /* clear error number of this thread to RT_EOK */
    if (thread->error == -RT_ETIMEOUT)
        thread->error = RT_EOK;

    return RT_EOK;
}

LOG_D()

In this study , We can LOG_D() As rt_kprintf(),

#define dbg_log_line(lvl, color_n, fmt, ...) \ do \ {
       \ _DBG_LOG_HDR(lvl, color_n); \ rt_kprintf(fmt, ##__VA_ARGS__); \ _DBG_LOG_X_END; \ } \ while (0)

LOG_D yes RT-Thread A log printing function in the kernel , Details visible ：《RT-Thread Document center ——ulog journal 》

RT-Thread Log API Include ：

rt_pin_write()

GPIO Write function , Here is the definition of the function ,

void rt_pin_write(rt_base_t pin, rt_base_t value)
{
    
    RT_ASSERT(_hw_pin.ops != RT_NULL);
    _hw_pin.ops->pin_write(&_hw_pin.parent, pin, value);
}

and GPIO The mode configuration function is similar , It will call the corresponding function in the underlying driver , The underlying function is through HAL_GPIO_WritePin() To complete GPIO Pin Modification of .

static void stm32_pin_write(rt_device_t dev, rt_base_t pin, rt_base_t value)
{
    
    const struct pin_index *index;

    index = get_pin(pin);
    if (index == RT_NULL)
    {
    
        return;
    }

    HAL_GPIO_WritePin(index->gpio, index->pin, (GPIO_PinState)value);
}