RT-Thread-【NK-980评测】SPI功能测试及其LoRa模块驱动RT-Thread问答社区

【NK-980评测】SPI功能测试及其LoRa模块驱动

发布于 2022-03-31 19:53:57 浏览：1733 订阅该版

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# 1 前言
本文主要描述了NUC980 SPI外设，及基于NK-980IoT开发板(SPI0外设)进行LoRa SPI模块的通信验证。
NK-980IOT开发板常用 板载资源 如下：
- 处理器：NUC980DK61Y
  - 主频 300MHz
  - 内嵌 64MB DDR SDRAM
- 板载资源：
  - 1Gbit SPI-NAND Flash、NAU8822 Audio Codec
  - 常用外设
    - LED：3 个
    - 用户按键：2 个
    - 复位按键：1个
  - 常用接口：Arduino、USB 转串口、RJ-45 接口、1xUSB host 2.0、1xUSB Dual-role 2.0、Micro SD。
  - 调试接口：外挂 J-link 调试 或 使用 NuWriter 烧录软件、SDRAM 下载。
- 开发板更多详细信息请参考 [Nuvoton Direct](https://direct.nuvoton.com/tw/numaker-iiot-nuc980)。
2 NCU980 SPI简述
NCU980 SPI具有如下特点:
  - 支持2路SPI
    - SPI0,SPI1
  - 支持主机与从机模式
    - 主机模式支持高达100M，
    - 从机模式支持高达30M
  - 支持8~32 bit字长
  - 支持4-level depth发送与接收FIFO
  - 支持PDMA传输
![image.png](https://oss-club.rt-thread.org/uploads/20220331/5d5511a1eaaaaefaae14d40365844105.png.webp)

## 2.1 NK-980IOT开发板SPI接口
![image.png](https://oss-club.rt-thread.org/uploads/20220331/35896a4eae9f4b28b1a1859b46b0aa33.png.webp)

- NK-980IoT
  - JTAG接口
  - SPI0
  - UART0 - 串口shell
- SX1278 SPI模块
  - VCC、GND、SI、SO、SCK、RESET、CS、DIO0
### 2.1.1 板载SPI0接口(位号NU5)
![image.png](https://oss-club.rt-thread.org/uploads/20220331/455366f74612cda38c4e8e764c16f15c.png.webp)

板载SPI0接口
### 2.1.2 板载Arduino接口 SPI1(位号NU1、NU2、NU3、NU4)
注： Arduino接口的SPI1接口连接到了JTAG，因此不能同时使用arduino接口SPI1与JTAG调试。
![image.png](https://oss-club.rt-thread.org/uploads/20220331/9d1892c053ccb511b97b3cfd90c6274e.png.webp)
板载SPI1接口

## 2.2 SPI外设引脚分配
通过设置寄存器 SYS_GPx_MFPH、SYS_GPx_MFPL (x=A\B\C\D..)来设置指定SPI外设引脚
![image.png](https://oss-club.rt-thread.org/uploads/20220331/87bdeab38d8449e2b42d8a6308d2f6c0.png.webp)

### 2.2.1 SPI0外设引脚设置
NUC980 SPI0引脚第二功能设置

![image.png](https://oss-club.rt-thread.org/uploads/20220331/9dfee83b510c94b93dd7b442a42ebadc.png.webp)

板载SPI0接口（位号NU5）使用了PD8、PD9、PD10、PD11，其对应为MFP1，同时默认配置为4线SPI（硬件CS控制），此处修改为软件控制CS，因此REG_SYS_GPD_MFPH设置为 0x00001110，即
  - MFP_GPD8 = 0
  - MFP_GPD9 = 1
  - MFP_GPD10 = 1
  - MFP_GPD11 = 1
```
//nu_pin_init.c
static void nu_pin_spi_init(void)
{
    /* SPI0: PD[9, 11] ，PD8设置普通IO */
    outpw(REG_SYS_GPD_MFPH, (inpw(REG_SYS_GPD_MFPH) & ~0x0000FFFF) | 0x00001110);
}
```
# 3 NUC980 BSP使用
## 3.1 开发工具
- RT-Thread Studio 2.2.1
- MDK5.30
- NK-980IoT BSP
## 3.2 调试接口(JTAG)
![image.png](https://oss-club.rt-thread.org/uploads/20220331/7825aa698291c2cb431696dc5b7a20a4.png.webp)

# 4 NUC980 LoRa通信
## 4.1  NK-980 LoRa SPI模块SX127x硬件连接
本次测试使用NK-980开发板的SPI0接口(NU05)，当前测试了LoRa SX127x模块。
![image.png](https://oss-club.rt-thread.org/uploads/20220331/902eec50f453d9abbccf44685f33d7d3.png)

## 4.2 LoRa Radio软件包使用
使能lora-radio软件包，配置如下所示
![image.png](https://oss-club.rt-thread.org/uploads/20220331/93e043daabd428c7f08b1f750427050d.png.webp)

“硬件”使能SPI0外设
![image.png](https://oss-club.rt-thread.org/uploads/20220331/df8ea31f59e3214079a2061a582803fd.png.webp)

当前lora-radio-driver软件包还未增加NK-980支持(后续加入)，目前需要进行如下修改
### 4.2.1 新增加 rt_hw_spi_device_attach
在libraries\\nuc980\\rtt_port\\drv_spi.c 新增加rt_hw_spi_device_attach，同时传入SPI CS引脚，用于通过软件方式控制lora模块CS引脚，见PR
```
//drv_spi.c
/**
  * Attach the spi device to SPI bus, this function must be used after initialization.
  */
rt_err_t rt_hw_spi_device_attach(const char *bus_name, const char *device_name, rt_base_t pin) 
{
    RT_ASSERT(bus_name != RT_NULL);
    RT_ASSERT(device_name != RT_NULL);
	
	  rt_err_t ret = RT_EOK;
    struct rt_spi_device *spi_device = (struct rt_spi_device *)rt_malloc(sizeof(struct rt_spi_device));
    RT_ASSERT(spi_device != RT_NULL);

struct nu_spi_cs *cs_pin = (struct nu_spi_cs *)rt_malloc(sizeof(struct nu_spi_cs));
    RT_ASSERT(cs_pin != RT_NULL);

cs_pin->pin = pin;
    rt_pin_mode(pin, PIN_MODE_OUTPUT);
    rt_pin_write(pin, PIN_HIGH);

ret = rt_spi_bus_attach_device(spi_device, device_name, bus_name, (void *)cs_pin);
    if (ret != RT_EOK)
    {
        LOG_E("%s attach to %s faild, %d\n", device_name, bus_name, ret);
    }

RT_ASSERT(ret == RT_EOK);

LOG_D("%s attach to %s done", device_name, bus_name);

return ret;
}
```
### 4.2.2 重定义lora模块gpio口
修改lora-radio-driver软件包中sx1278-board.c，手动增加 lora模块SPI NSS、RESET、DIO0引脚定义	
注 #define NU_GET_PININDEX(port, pin)        ((port)*16+(pin))
```
//sx1278-board.c 
#include <drv_gpio.h>
		
    #ifndef LORA_RADIO0_NSS_PIN
    #define LORA_RADIO0_NSS_PIN    NU_GET_PININDEX(NU_PD,8)
    #endif
    #ifndef LORA_RADIO0_RESET_PIN
    #define LORA_RADIO0_RESET_PIN  NU_GET_PININDEX(NU_PF,8)
    #endif
    #ifndef LORA_RADIO0_DIO0_PIN
    #define LORA_RADIO0_DIO0_PIN   NU_GET_PININDEX(NU_PF,7)
    #endif
```
注意nk-980iot bsp默认开启了PF7,PF8为pwm输出，这里用作LoRa模块的RESET、DIO0，因此要屏蔽如下部分
```
static void nu_pin_pwm_init(void)
{
    /* PWM02, PWM03: PF[7, 8]  */
    //outpw(REG_SYS_GPF_MFPL, (inpw(REG_SYS_GPF_MFPL) & ~0xF0000000) | 0x40000000);
    //outpw(REG_SYS_GPF_MFPH, (inpw(REG_SYS_GPF_MFPH) & ~0x0000000F) | 0x00000004);
}
```

### 4.2.3 绑定lora设备到spi0总线
修改lora-radio-driver软件包中lora-spi-board.c,绑定lora-radio设备与LORA_RADIO0_NSS_PIN到spi0总线
```
//lora-spi-board.c
struct rt_spi_device *lora_radio_spi_init(const char *bus_name, const char *lora_device_name, uint8_t param)
{
    rt_err_t res;
    struct rt_spi_device *lora_radio_spi_device;
    
    RT_ASSERT(bus_name);
    
    // ...

res = rt_hw_spi_device_attach( bus_name, lora_device_name, LORA_RADIO0_NSS_PIN);
    
    //.....
}
```
### 4.2.3 更新nu_spi_bus_xfer
注意如果使用RT-Thread Studio 2.2.1,RT-Thread内核默认当前是4.0.3版本，\libraries\nuc980\rtt_port\drv_spi.c 非master最新代码，不支持由用户软件控制SPI CS，需更新如下
```
static rt_uint32_t nu_spi_bus_xfer(struct rt_spi_device *device, struct rt_spi_message *message)
{
    struct nu_spi *spi_bus;
    struct rt_spi_configuration *configuration;
    uint8_t bytes_per_word;
    void *pvUserData;

RT_ASSERT(device != RT_NULL);
    RT_ASSERT(device->bus != RT_NULL);
    RT_ASSERT(message != RT_NULL);

spi_bus = (struct nu_spi *) device->bus;
    configuration = (struct rt_spi_configuration *)&spi_bus->configuration;
    bytes_per_word = configuration->data_width / 8;
    pvUserData = device->parent.user_data;

if ((message->length % bytes_per_word) != 0)
    {
        /* Say bye. */
        LOG_E("%s: error payload length(%d%%%d != 0).\n", spi_bus->name, message->length, bytes_per_word);
        return 0;
    }

if (message->length > 0)
    {
        if (message->cs_take && !(configuration->mode & RT_SPI_NO_CS))
        {
            if (pvUserData != RT_NULL) // 软件控制SPI CS引脚
            {
                if (configuration->mode & RT_SPI_CS_HIGH)
                {
                    // set to HIGH */
                    rt_pin_write(*((rt_base_t *)pvUserData), PIN_HIGH);
                }
                else
                {
                    // set to LOW */
                    rt_pin_write(*((rt_base_t *)pvUserData), PIN_LOW);
                }
            }
            else
            {
                if (configuration->mode & RT_SPI_CS_HIGH)
                {
                    SPI_SET_SS_HIGH(spi_bus->spi_base);
                }
                else
                {
                    SPI_SET_SS_LOW(spi_bus->spi_base);
                }
            }
        }

nu_spi_transfer(spi_bus, (uint8_t *)message->send_buf, (uint8_t *)message->recv_buf, message->length, bytes_per_word);

if (message->cs_release && !(configuration->mode & RT_SPI_NO_CS))
        {
            if (pvUserData != RT_NULL)// 软件控制SPI CS引脚
            {
                if (configuration->mode & RT_SPI_CS_HIGH)
                {
                    // set to LOW */
                    rt_pin_write(*((rt_base_t *)pvUserData), PIN_LOW);
                }
                else
                {
                    // set to HIGH */
                    rt_pin_write(*((rt_base_t *)pvUserData), PIN_HIGH);
                }
            }
            else
            {
                if (configuration->mode & RT_SPI_CS_HIGH)
                {
                    SPI_SET_SS_LOW(spi_bus->spi_base);
                }
                else
                {
                    SPI_SET_SS_HIGH(spi_bus->spi_base);
                }
            }
        }

}

return message->length;
}
```
## 4.3 测试结果
![nk-980-lora-ping-sf7-4703.gif](https://oss-club.rt-thread.org/uploads/20220331/04660dca4f37f40032fa779db7102ab1.gif)

- 测试过程如下
  - 左侧为NK-980 + LoRa SX1278模块，作为master
    - 首先执行lora probe
      - 检测lora模块spi是否访问正常
    - 执行 lora ping -m 发送lora数据包给从机，等待从机应答
  - 右侧为STM32L4 + LoRa SX1268模块，作为slaver
    - 执行 lora ping -s
      - 接收到master数据包后，回传给master
# 5 注意事项
1. Arduino接口的SPI1接口连接到了JTAG，因此不能同时使用arduino接口SPI1与JTAG调试。
2. JTAG连接线不能太长，否则可能出现debug异常
3. 使用外设功能引脚，注意根据实际引脚配置MFP功能，比如SPI0 MOSI-> PD.10 -> MFP1
  a. NK-980引脚初始化配置位于nu_pin_init.c
  
# 6 示例代码
基于RT-Thread Studio 2.2.1 测试代码
  https://gitee.com/forest-rain/nk-980iot-lora-radio