RT-Thread-Numaker-IoT-M487 ECAP 功能评测RT-Thread问答社区

Numaker-IoT-M487 ECAP 功能评测

发布于 2022-04-27 17:29:45 浏览：675 订阅该版

一、M487 ECAP简介
6.15.1 概述
M480 系列提供了多达两组的增强型输入捕捉定时器/计数器，以用于检测输入通道边沿信号的改变。每
个单元含有三路输入通道。定时器/计数器有向上计数、重载及比较匹配的功能。
6.15.2 特性
 多达两组输入捕捉定时器/计数器单元，CAP0和CAP1
 每个单元都有3个输入通道
 每个单元都有独立的中断向量
 每个输入通道都有对应的捕捉计数器保持寄存器
 24位的输入捕捉向上计数定时器/计数器
 在输入端末前附有噪声过滤
 三种边沿检测：
– 上升沿检测
– 下降沿检测
– 双边沿检测
 支持用被捕捉的事情复位/重载捕捉计数器
 支持比较匹配功能

二、软件测试环境
KEIL MDK v5.26
Env RT-Thread 开发辅助工具。
终端联机工具Tera Term V4.99
RT-Thread 标准版系统及bsp包

三、硬件环境
NuMaker-IoT-M487
开发板更多详细信息请参考 [Nuvoton Direct](https://direct.nuvoton.com/en/numaker-iot-m487)。
[开发板原理图](https://www.nuvoton.com/resource-download.jsp?tp_GUID=HL0320180905131830)

四、开始建立测试环境
1.在官网下载Env RT-Thread 开发辅助工具包，包含了终端联机工具Tera Term；
2.根据[NuMaker-IoT-M487 上手指南](https://www.rt-thread.org/document/site/#/rt-thread-version/rt-thread-standard/tutorial/quick-start/numaker-iot-m487/quick-start)
 下载更新RT-Thread 标准版系统及bsp包
 
3.在ENV环境下，输入cd rt-thread>> cd bsp/nuvoton/numaker-iot-m487>>menuconfig打开系统配置界面，Hardware Drivers Config>>On-Chip Peripheral Drivers >>Enable Enhance Input Capture Timer>>Enable ECAP0>> 0X01(Specify Channel Mark for ECAP0 Channel);
如图：![20.png](https://oss-club.rt-thread.org/uploads/20220427/fd41febc3c4bf0a7bf6e79356dc76d0c.png)![21.png](https://oss-club.rt-thread.org/uploads/20220427/9992156cbc6c4cf406ffd8989cc6c812.png)

最后输入scons --target=mdk5 进行编译；
打开KEIL编译通过后下载到板上；通过终端联机工具Tera Term 输入list_device查询
如图![22.png](https://oss-club.rt-thread.org/uploads/20220427/c3b9bfd6f958d2d4e746a9bdaf1b8391.png.webp)
出现ecap0i0接口对象， 说明项目配置成功；

4.找出M487 ECAP0 对应的IO  PA10,如图
![23.png](https://oss-club.rt-thread.org/uploads/20220427/2dfdf19a859e418734a480938eef1e7d.png)

在nutool_pincfg.c 中的nutool_pincfg_init 和nutool_pincfg_deinit中分别加入：    nutool_pincfg_init_ecap0()，    nutool_pincfg_deinit_ecap0();
```
void nutool_pincfg_init_ecap0(void)
{
    /* Set PA.10 for ECAP0_IC0*/
    SYS->GPA_MFPH = (SYS->GPA_MFPH & ~SYS_GPA_MFPH_PA10MFP_Msk) |SYS_GPA_MFPH_PA10MFP_ECAP0_IC0;
}

void nutool_pincfg_deinit_ecap0(void)
{
    /* Set PA.10 for ECAP0_IC0*/
    SYS->GPA_MFPH = (SYS->GPA_MFPH & ~SYS_GPA_MFPH_PA10MFP_Msk);
}
```

如图:![24.png](https://oss-club.rt-thread.org/uploads/20220427/2e244a79c063f8ef95afae6d8756b22d.png)

5.找出NuMaker-IoT-M487 对应的测试端子；
![26.png](https://oss-club.rt-thread.org/uploads/20220427/b21bbc4e33a68b0b02922a3f05101cb9.png.webp)

然后将杜邦线连接：![ECAP0_PA10_PA1.jpg](https://oss-club.rt-thread.org/uploads/20220427/5c6f8aa05061537a289933f4e37d0991.jpg.webp)

6.开始代码测试
用keil 打开 rt-thread\bsp\nuvoton\numaker-iot-m487 目录下project项目；在       applications 下新增 ECAP0_test.c；
```
#include "rtthread.h"
#include "rtdevice.h"
#include "NuMicro.h"
#include <drv_gpio.h>

#define Input_Push   NU_GET_PININDEX(NU_PA, 0)
//#define B0   NU_GET_PININDEX(NU_PA, 10)
rt_size_t g_size;

typedef struct _ecap_dev
{
    ECAP_T      *ecap_base;
    float       fUsPerTick;
} nu_ecap_dev_t;

typedef struct _ecap
{
    struct rt_inputcapture_device   parent;
    nu_ecap_dev_t *ecap_dev;
    uint8_t     u8Channel;
    rt_bool_t   bfirstData;
    uint32_t    u32CurrentCnt;
    uint32_t    u32LastCnt;
    rt_bool_t   input_data_level;
} nu_capture_t;

static rt_err_t ecap0_rx_callback(rt_device_t dev, rt_size_t size)
{
    rt_kprintf("%d\r\n",size);
	  g_size = size;
    return 0;
}

void ecap_thread_entry(void *arc)
{
	 rt_int32_t  s32_Count = 0;

rt_device_t ecap_ops=rt_device_find("ecap0i0");
    if(ecap_ops == RT_NULL)
    {
        rt_kprintf("not find device ecap0i0 \r\n");
        return ;
    }
	 
    rt_kprintf("find device ecap0i0\r\n");
	     
	 rt_device_open(ecap_ops, RT_NULL);   //
	 
	 rt_device_set_rx_indicate(ecap_ops, ecap0_rx_callback);

while(1)
    { 
		 if( s32_Count < 100 )
       { 		 
			 rt_pin_write(Input_Push, PIN_HIGH);
			 rt_thread_delay(2);
			 if( g_size > 50 )  rt_kprintf(" high level pulse, rx_Callback %d, Count:%d, capture level:%d \r\n", g_size, s32_Count,((nu_capture_t*)ecap_ops)->input_data_level );
			 s32_Count++;

rt_pin_write(Input_Push, PIN_LOW);
		    rt_thread_delay(2);
			 if( g_size > 50 )  rt_kprintf(" low level pulse,rx_Callback %d, Count:%d, capture level:%d \r\n", g_size, s32_Count,((nu_capture_t*)ecap_ops)->input_data_level );
			 s32_Count++;
		 }
		 else
		   rt_thread_delay(2); 
    }
}

int run_ecap0(void)
{
	 rt_pin_mode(Input_Push, PIN_MODE_OUTPUT);
	 rt_pin_write(Input_Push, PIN_LOW);
	
    rt_thread_t tid = RT_NULL;
    tid = rt_thread_create("ecap_test_thd", ecap_thread_entry, RT_NULL, 2048, 12, 10);
    if (tid != RT_NULL)
    {
       rt_thread_startup(tid);
    }
    else
    {
       return RT_ERROR;
    }
    return RT_EOK;
}
//INIT_APP_EXPORT(run_qei);

MSH_CMD_EXPORT(run_ecap0 , ecap0 test );

```
编译通过后下载到板上；
打开
终端联机工具Tera Term 输入run_ecap0；

如图：![27.png](https://oss-club.rt-thread.org/uploads/20220427/31ab355b3c5e14ba5acedd8fd68e596a.png.webp)

实现了 通过中断函数调用CallBack函数返回捕捉到的输入电平状态；

五、测评总结

1、ECAP模块 作为 "Miscellaneous Device"  个人感觉对ECAP还不熟悉；
2、发现了一个BUG:Dev_ecap.c ->void ECAP0_IRQHandler(void) 以下是修改过来 ```
        if (NU_ECAP_GET_LEVEL(u32Status, 0))
        {
            nu_ecap0_capture[0]->input_data_level = RT_TRUE;
        }
        else
        {
            nu_ecap0_capture[0]->input_data_level = RT_FALSE;
        }
```