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RT-Thread STM32L475 IoT Discovery kit BSP说明①

RT-Thread STM32L475 IoT Discovery kit BSP说明①,Linux,ARM MCU,MCU C51,stm32,linux,arm开发,运维,物联网,嵌入式硬件,单片机

简介

本文档为 RT-Thread 开发团队为 STM32L475 IoT Discovery kit开发板提供的 BSP (板级支持包) 说明。

主要内容如下：

开发板资源介绍
BSP 快速上手
进阶使用方法

通过阅读快速上手章节开发者可以快速地上手该 BSP，将 RT-Thread 运行在开发板上。在进阶使用指南章节，将会介绍更多高级功能，帮助开发者利用 RT-Thread 驱动更多板载资源。

开发板介绍

STM32L475 IoT Discovery kit 是 ST 官方推出的一款基于 ARM Cortex-M4 内核的开发板，最高主频为 80Mhz，该开发板具有丰富的板载资源，可以充分发挥 STM32L475 的芯片性能。

开发板外观如下图所示：
RT-Thread STM32L475 IoT Discovery kit BSP说明①,Linux,ARM MCU,MCU C51,stm32,linux,arm开发,运维,物联网,嵌入式硬件,单片机

该开发板常用 板载资源 如下：

MCU：STM32L475VGT6，主频 80MHz，1024KB FLASH ，128KB RAM
常用外设
- 姿态传感器
- 加速度传感器
- 磁力计
- 接近传感器
- 压力传感器
- 湿度传感器
- 扩音器
- 板载 ST LINK V2.1 功能
常用接口：USB OTG、Arduino Uno 和 Pmod 接口
调试接口：ST-LINK Micro USB 接口(ST-LINK 转串口对应串口1)
支持 mbed

开发板更多详细信息请参考ST官方网站 STM32 开发板介绍

外设支持

本 BSP 目前对片上外设的支持情况如下：

片上外设	支持情况	备注
GPIO	支持
UART	支持	UART1

使用说明

使用说明分为如下两个章节：

快速上手

本章节是为刚接触 RT-Thread 的新手准备的使用说明，遵循简单的步骤即可将 RT-Thread 操作系统运行在该开发板上，看到实验效果。
进阶使用

本章节是为需要在 RT-Thread 操作系统上使用更多开发板资源的开发者准备的。通过使用 ENV 工具对 BSP 进行配置，可以开启更多板载资源，实现更多高级功能。

快速上手

本 BSP 为开发者提供 MDK5 和 IAR 工程，并且支持 GCC 开发环境。下面以 MDK5 开发环境为例，介绍如何将系统运行起来。

硬件连接

使用数据线连接开发板到 PC。

编译下载

双击 project.uvprojx 文件，打开 MDK5 工程，编译并下载程序到开发板。

工程默认配置使用板载 ST-LINK 下载程序，只需一根 USB 线连接开发板，点击下载按钮即可下载程序到开发板

运行结果

下载程序成功之后，系统会自动运行，观察开发板上 LED 的运行效果，绿色 LED 会周期性闪烁。

连接开发板对应串口到 PC , 在终端工具里打开相应的串口（115200-8-1-N），复位设备后，可以看到 RT-Thread 的输出信息:

 \ | /
- RT -     Thread Operating System
 / | \     4.0.1 build Mar 18 2019
 2006 - 2019 Copyright by rt-thread team

进阶使用

此 BSP 默认只开启了 GPIO 和串口1 的功能，如果需使用更多高级功能，需要利用 ENV 工具对 BSP 进行配置，步骤如下：

在 bsp 下打开 env 工具。
输入menuconfig命令配置工程，配置好之后保存退出。
输入pkgs --update命令更新软件包。
输入scons --target=mdk4/mdk5/iar 命令重新生成工程。

本章节更多详细的介绍请参考 STM32 系列 BSP 外设驱动使用教程。

注意事项

暂无

示例代码

…\src\ipc.c

static rt_ssize_t _rt_mq_recv(rt_mq_t mq,
                              void *buffer,
                              rt_size_t size,
                              rt_int32_t *prio,
                              rt_int32_t timeout,
                              int suspend_flag)
{
    struct rt_thread *thread;
    rt_base_t level;
    struct rt_mq_message *msg;
    rt_uint32_t tick_delta;
    rt_err_t ret;
    rt_size_t len;

    /* parameter check */
    RT_ASSERT(mq != RT_NULL);
    RT_ASSERT(rt_object_get_type(&mq->parent.parent) == RT_Object_Class_MessageQueue);
    RT_ASSERT(buffer != RT_NULL);
    RT_ASSERT(size != 0);

    /* current context checking */
    RT_DEBUG_SCHEDULER_AVAILABLE(timeout != 0);

    /* initialize delta tick */
    tick_delta = 0;
    /* get current thread */
    thread = rt_thread_self();
    RT_OBJECT_HOOK_CALL(rt_object_trytake_hook, (&(mq->parent.parent)));

    level = rt_spin_lock_irqsave(&(mq->spinlock));

    /* for non-blocking call */
    if (mq->entry == 0 && timeout == 0)
    {
        rt_spin_unlock_irqrestore(&(mq->spinlock), level);

        return -RT_ETIMEOUT;
    }

    /* message queue is empty */
    while (mq->entry == 0)
    {
        /* reset error number in thread */
        thread->error = -RT_EINTR;

        /* no waiting, return timeout */
        if (timeout == 0)
        {
            /* enable interrupt */
            rt_spin_unlock_irqrestore(&(mq->spinlock), level);

            thread->error = -RT_ETIMEOUT;

            return -RT_ETIMEOUT;
        }

        /* suspend current thread */
        ret = _ipc_list_suspend(&(mq->parent.suspend_thread),
                            thread,
                            mq->parent.parent.flag,
                            suspend_flag);
        if (ret != RT_EOK)
        {
            rt_spin_unlock_irqrestore(&(mq->spinlock), level);
            return ret;
        }

        /* has waiting time, start thread timer */
        if (timeout > 0)
        {
            /* get the start tick of timer */
            tick_delta = rt_tick_get();

            LOG_D("set thread:%s to timer list",
                  thread->parent.name);

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

        rt_spin_unlock_irqrestore(&(mq->spinlock), level);

        /* re-schedule */
        rt_schedule();

        /* recv message */
        if (thread->error != RT_EOK)
        {
            /* return error */
            return thread->error;
        }

        level = rt_spin_lock_irqsave(&(mq->spinlock));

        /* if it's not waiting forever and then re-calculate timeout tick */
        if (timeout > 0)
        {
            tick_delta = rt_tick_get() - tick_delta;
            timeout -= tick_delta;
            if (timeout < 0)
                timeout = 0;
        }
    }

    /* get message from queue */
    msg = (struct rt_mq_message *)mq->msg_queue_head;

    /* move message queue head */
    mq->msg_queue_head = msg->next;
    /* reach queue tail, set to NULL */
    if (mq->msg_queue_tail == msg)
        mq->msg_queue_tail = RT_NULL;

    /* decrease message entry */
    if(mq->entry > 0)
    {
        mq->entry --;
    }

    rt_spin_unlock_irqrestore(&(mq->spinlock), level);

    /* get real message length */
    len = ((struct rt_mq_message *)msg)->length;

    if (len > size)
        len = size;
    /* copy message */
    rt_memcpy(buffer, GET_MESSAGEBYTE_ADDR(msg), len);

#ifdef RT_USING_MESSAGEQUEUE_PRIORITY
    if (prio != RT_NULL)
        *prio = msg->prio;
#endif
    level = rt_spin_lock_irqsave(&(mq->spinlock));
    /* put message to free list */
    msg->next = (struct rt_mq_message *)mq->msg_queue_free;
    mq->msg_queue_free = msg;

    /* resume suspended thread */
    if (!rt_list_isempty(&(mq->suspend_sender_thread)))
    {
        _ipc_list_resume(&(mq->suspend_sender_thread));

        rt_spin_unlock_irqrestore(&(mq->spinlock), level);

        RT_OBJECT_HOOK_CALL(rt_object_take_hook, (&(mq->parent.parent)));

        rt_schedule();

        return len;
    }

    rt_spin_unlock_irqrestore(&(mq->spinlock), level);

    RT_OBJECT_HOOK_CALL(rt_object_take_hook, (&(mq->parent.parent)));

    return len;
}

rt_ssize_t rt_mq_recv(rt_mq_t    mq,
                    void      *buffer,
                    rt_size_t  size,
                    rt_int32_t timeout)
{
    return _rt_mq_recv(mq, buffer, size, 0, timeout, RT_UNINTERRUPTIBLE);
}
RTM_EXPORT(rt_mq_recv);

rt_ssize_t rt_mq_recv_interruptible(rt_mq_t    mq,
                    void      *buffer,
                    rt_size_t  size,
                    rt_int32_t timeout)
{
    return _rt_mq_recv(mq, buffer, size, 0, timeout, RT_INTERRUPTIBLE);
}
RTM_EXPORT(rt_mq_recv_interruptible);

rt_ssize_t rt_mq_recv_killable(rt_mq_t    mq,
                    void      *buffer,
                    rt_size_t  size,
                    rt_int32_t timeout)
{
    return _rt_mq_recv(mq, buffer, size, 0, timeout, RT_KILLABLE);
}
#ifdef RT_USING_MESSAGEQUEUE_PRIORITY
rt_err_t rt_mq_send_wait_prio(rt_mq_t mq,
                              const void *buffer,
                              rt_size_t size,
                              rt_int32_t prio,
                              rt_int32_t timeout,
                              int suspend_flag)
{
    return _rt_mq_send_wait(mq, buffer, size, prio, timeout, suspend_flag);
}
rt_ssize_t rt_mq_recv_prio(rt_mq_t mq,
                           void *buffer,
                           rt_size_t size,
                           rt_int32_t *prio,
                           rt_int32_t timeout,
                           int suspend_flag)
{
    return _rt_mq_recv(mq, buffer, size, prio, timeout, suspend_flag);
}
#endif
RTM_EXPORT(rt_mq_recv_killable);
/**
 * @brief    This function will set some extra attributions of a messagequeue object.
 *
 * @note     Currently this function only supports the RT_IPC_CMD_RESET command to reset the messagequeue.
 *
 * @param    mq is a pointer to a messagequeue object.
 *
 * @param    cmd is a command used to configure some attributions of the messagequeue.
 *
 * @param    arg is the argument of the function to execute the command.
 *
 * @return   Return the operation status. When the return value is RT_EOK, the operation is successful.
 *           If the return value is any other values, it means that this function failed to execute.
 */
rt_err_t rt_mq_control(rt_mq_t mq, int cmd, void *arg)
{
    rt_base_t level;
    struct rt_mq_message *msg;

    /* parameter check */
    RT_ASSERT(mq != RT_NULL);
    RT_ASSERT(rt_object_get_type(&mq->parent.parent) == RT_Object_Class_MessageQueue);

    if (cmd == RT_IPC_CMD_RESET)
    {
        level = rt_spin_lock_irqsave(&(mq->spinlock));

        /* resume all waiting thread */
        _ipc_list_resume_all(&mq->parent.suspend_thread);
        /* also resume all message queue private suspended thread */
        _ipc_list_resume_all(&(mq->suspend_sender_thread));

        /* release all message in the queue */
        while (mq->msg_queue_head != RT_NULL)
        {
            /* get message from queue */
            msg = (struct rt_mq_message *)mq->msg_queue_head;

            /* move message queue head */
            mq->msg_queue_head = msg->next;
            /* reach queue tail, set to NULL */
            if (mq->msg_queue_tail == msg)
                mq->msg_queue_tail = RT_NULL;

            /* put message to free list */
            msg->next = (struct rt_mq_message *)mq->msg_queue_free;
            mq->msg_queue_free = msg;
        }

        /* clean entry */
        mq->entry = 0;

        rt_spin_unlock_irqrestore(&(mq->spinlock), level);

        rt_schedule();

        return RT_EOK;
    }

    return -RT_ERROR;
}
RTM_EXPORT(rt_mq_control);

/**@}*/
#endif /* RT_USING_MESSAGEQUEUE */
/**@}*/