普冉PY32系列(八) GPIO模擬和硬件SPI方式驅(qū)動(dòng)無(wú)線(xiàn)收發(fā)芯片XN297LBW

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普冉PY32系列(一) PY32F0系列32位Cortex M0+ MCU簡(jiǎn)介
普冉PY32系列(二) Ubuntu GCC Toolchain和VSCode開(kāi)發(fā)環(huán)境
普冉PY32系列(三) PY32F002A資源實(shí)測(cè) - 這個(gè)型號(hào)不簡(jiǎn)單
普冉PY32系列(四) PY32F002A/003/030的時(shí)鐘設(shè)置
普冉PY32系列(五) 使用JLink RTT代替串口輸出日志
普冉PY32系列(六) 通過(guò)I2C接口驅(qū)動(dòng)PCF8574擴(kuò)展的1602LCD
普冉PY32系列(七) SOP8,SOP10,SOP16封裝的PY32F002A/PY32F003管腳復(fù)用
普冉PY32系列(八) GPIO模擬和硬件SPI方式驅(qū)動(dòng)無(wú)線(xiàn)收發(fā)芯片XN297LBW
普冉PY32系列(九) GPIO模擬和硬件SPI方式驅(qū)動(dòng)無(wú)線(xiàn)收發(fā)芯片XL2400
普冉PY32系列(十) 基于PY32F002A的6+1通道遙控小車(chē)I - 綜述篇
普冉PY32系列(十一) 基于PY32F002A的6+1通道遙控小車(chē)II - 控制篇
普冉PY32系列(十二) 基于PY32F002A的6+1通道遙控小車(chē)III - 驅(qū)動(dòng)篇

XN297LBW

XN297LBW 是一個(gè)SOP8封裝的2.4GHz頻段無(wú)線(xiàn)收發(fā)芯片, 價(jià)格在1元左右, 適用于低成本應(yīng)用. 雖然磐啟已經(jīng)發(fā)布了 XN297L 的下一代產(chǎn)品 PAN1026, 但是市面上基本上見(jiàn)不到后者的身影, 零售能買(mǎi)到的還是 XN297L.

普冉PY32系列(八) GPIO模擬和硬件SPI方式驅(qū)動(dòng)無(wú)線(xiàn)收發(fā)芯片XN297LBW

生產(chǎn)商是上海磐啟, 產(chǎn)品頁(yè)地址: https://wiki.panchip.com/ble-lite/2-4g-t-rx/xn297l_series/

磐啟對(duì) XN297L 的產(chǎn)品介紹: "工作在 2.400~2.483GHz 世界通用 ISM 頻段的單片無(wú)線(xiàn)收發(fā)芯片, XN297L采用嵌入式基帶協(xié)議引擎, 適用于超低功耗無(wú)線(xiàn)應(yīng)用. 采用 GFSK 調(diào)制, 可配置頻率信道, 輸出功率和接口數(shù)據(jù)速率等射頻參數(shù). XN297L 支持 2Mbps, 1Mbps 和 250Kbps 的數(shù)據(jù)速率. 對(duì)于長(zhǎng)距離應(yīng)用, 輸出功率可以調(diào)節(jié)高達(dá) 11dBm, 對(duì)于短距離和超低功率應(yīng)用, 輸出功率可以低至-23dBm."

XN297LBW 主要特性

無(wú)線(xiàn)
- 通信頻段：2.400GHz~2.483GHz
- 數(shù)據(jù)速率：2Mbps,1Mbps,250Kbps
- 調(diào)制方式：GFSK
發(fā)射器
- 輸出功率：11, 9, 5, -1, -10 or -23dBm
- 18mA@2dBm
- 30mA@9dBm
接收器
- -83dBm@2Mbps
- -87dBm@1Mbps
- -91dBm@250Kbps
協(xié)議引擎
- 支持1到32字節(jié)或64字節(jié)數(shù)據(jù)長(zhǎng)度
- 支持自動(dòng)應(yīng)答及自動(dòng)重傳
- 6個(gè)接收數(shù)據(jù)通道構(gòu)成1:6的星狀網(wǎng)絡(luò)
電源管理
- 工作電壓：2.3~3.3V
- 2uA斷電模式
- 30uA待機(jī)-Ⅰ模式
主機(jī)接口
- 支持3引腳SPI, 4Mbps SPI接口速率
- 支持兩個(gè)獨(dú)立的32字節(jié)TX和RX FIFOs
- 支持一個(gè)64字節(jié)的TX和RX FIFOs
封裝
- SOP8

這里要注意的幾點(diǎn):

工作電壓是3.3V, 不要錯(cuò)接5V.
SPI速率為4MHz, 實(shí)測(cè)上限不會(huì)比4MHz高多少, 在6MHz頻率時(shí)大概率SPI通信錯(cuò)誤導(dǎo)致不能工作.
TX FIFO 與NRF24L01相比只有兩個(gè)32字節(jié), 而NRF24L01是3個(gè)32字節(jié). 性能相對(duì)縮水.

PIN腳定義和應(yīng)用電路

PIN腳定義

VDD 和 VSS 分別接 VCC 和 GND
XC1 和 XC2 接晶振
ANT 接天線(xiàn)
用于MCU接口通信的只有 CSN, SCK 和 DATA 這三個(gè)PIN

普冉PY32系列(八) GPIO模擬和硬件SPI方式驅(qū)動(dòng)無(wú)線(xiàn)收發(fā)芯片XN297LBW

應(yīng)用電路

普冉PY32系列(八) GPIO模擬和硬件SPI方式驅(qū)動(dòng)無(wú)線(xiàn)收發(fā)芯片XN297LBW

模塊實(shí)物

嘉立創(chuàng)打樣的測(cè)試模塊 (項(xiàng)目地址 https://oshwhub.com/iosetting/xn297lbw-xl2400-evb)

普冉PY32系列(八) GPIO模擬和硬件SPI方式驅(qū)動(dòng)無(wú)線(xiàn)收發(fā)芯片XN297LBW

使用PY32F0驅(qū)動(dòng)XN297LBW

XN297L最新的SDK可以從磐啟的論壇下載論壇?BLE-Lite系列2.4GHz TRX?XN297L?XN297L_SDK. 因?yàn)槊嫦虻闹饕堑统杀緫?yīng)用, 大多數(shù)搭配的MCU為廉價(jià)的8位8051, 不一定有硬件SPI, 為了保證兼容在SDK中使用的都是GPIO模擬SPI方式進(jìn)行驅(qū)動(dòng). 但是實(shí)際上是可以通過(guò)硬件SPI方式進(jìn)行驅(qū)動(dòng)的.

以下分別對(duì)GPIO模擬和硬件SPI方式的驅(qū)動(dòng)進(jìn)行介紹.

硬件準(zhǔn)備

XN297LBW模塊
PY32F002A/PY32F003/PY32F030 系列MCU的開(kāi)發(fā)板, 建議在驗(yàn)證階段使用 20PIN 及以上封裝的型號(hào), 避免PIN腳復(fù)用引起的干擾. 跑通后再遷移到低PIN型號(hào)
USB2TTL模塊, 用于觀察輸出
以上硬件需要兩套, 測(cè)試中分別用于接收和發(fā)送

下面以PY32F002A為例. 代碼不需調(diào)整可以直接運(yùn)行于 PY32F003x 和 PY32F030x 系列的其它型號(hào).

GPIO模擬方式

接線(xiàn)

注意電源使用3.3V

PY32          XN297LBW SOP8
PA1   ------> CLK/SCK
PA6   ------> CSN/NSS
PA7   ------> DATA/MOSI

              USB2TTL
PA2(TX) ----> RX
PA3(RX) ----> TX

代碼說(shuō)明

SDK代碼中使用的MCU是STM8L, 需要遷移到 PY32F002A.

將 xn297l.h 中的 GPIO 設(shè)置換為PY32F002A的PIN腳

#define XN297L_DATA_OUT()        LL_GPIO_SetPinMode(GPIOA, LL_GPIO_PIN_7, LL_GPIO_MODE_OUTPUT)
#define XN297L_DATA_IN()         LL_GPIO_SetPinMode(GPIOA, LL_GPIO_PIN_7, LL_GPIO_MODE_INPUT)
#define XN297L_DATA_LOW()        LL_GPIO_ResetOutputPin(GPIOA, LL_GPIO_PIN_7)
#define XN297L_DATA_HIGH()       LL_GPIO_SetOutputPin(GPIOA, LL_GPIO_PIN_7)
#define XN297L_DATA_READ()       LL_GPIO_IsInputPinSet(GPIOA, LL_GPIO_PIN_7)

#define XN297L_SCK_LOW()         LL_GPIO_ResetOutputPin(GPIOA, LL_GPIO_PIN_1)
#define XN297L_SCK_HIGH()        LL_GPIO_SetOutputPin(GPIOA, LL_GPIO_PIN_1)

#define XN297L_CSN_LOW()         LL_GPIO_ResetOutputPin(GPIOA, LL_GPIO_PIN_6)
#define XN297L_CSN_HIGH()        LL_GPIO_SetOutputPin(GPIOA, LL_GPIO_PIN_6)

#define XN297L_CE_LOW()          XN297L_WriteReg(XN297L_CMD_CE_FSPI_OFF, 0)
#define XN297L_CE_HIGH()         XN297L_WriteReg(XN297L_CMD_CE_FSPI_ON, 0)

在 main.c 中增加GPIO初始化

static void APP_GPIOConfig(void)
{
  LL_GPIO_InitTypeDef GPIO_InitStruct;

  /* PA1 CLK */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_1;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);
  /* PA6 CSN */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_6;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);
  /* PA7 DATA */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_7;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_INPUT;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}

使用GPIO模擬SPI的字節(jié)寫(xiě)

/**
 * Emulate SPI Write on GPIO pins
 */
void XN297L_WriteByte(uint8_t value)
{
    uint8_t i = 0;
    XN297L_SCK_LOW();
    XN297L_DATA_OUT();
    for (i = 0; i < 8; i++)
    {
        XN297L_SCK_LOW();
        if (value & 0x80)
        {
            XN297L_DATA_HIGH();
        }
        else
        {
            XN297L_DATA_LOW();
        }
        XN297L_SCK_HIGH();
        value = value << 1;
    }
    XN297L_SCK_LOW();
}

模擬字節(jié)讀. 這里有個(gè)細(xì)節(jié), 在XN297L_SCK_HIGH();之后加一個(gè)__NOP();, 如果沒(méi)有這個(gè)NOP(), PY32F0在低頻率(8MHz和24MHz)的時(shí)候容易產(chǎn)生讀取錯(cuò)誤.

/**
 * Emulate SPI Read on GPIO pins
 */
uint8_t XN297L_ReadByte(void)
{
    uint8_t i = 0, RxData = 0;

    XN297L_DATA_IN();
    for (i = 0; i < 8; i++)
    {
        RxData = RxData << 1;
        XN297L_SCK_HIGH();
        __NOP();
        if (XN297L_DATA_READ())
        {
            RxData |= 0x01;
        }
        else
        {
            RxData &= 0xfe;
        }
        XN297L_SCK_LOW();
    }
    return RxData;
}

XN297L 的初始化. 這部分是相對(duì)固定的流程, 可以根據(jù)自己的需要進(jìn)行調(diào)整, 但是在測(cè)試階段務(wù)必保持接收端和發(fā)送端的配置一致. 這里在SDK的代碼上做了一些修改, 開(kāi)啟了發(fā)送的重試和ACK.

// 這部分來(lái)自于手冊(cè) "XN297L 軟件設(shè)計(jì)和調(diào)試參考"
const uint8_t 
    BB_cal_data[]    = {0x12,0xED,0x67,0x9C,0x46},
    RF_cal_data[]    = {0xF6,0x3F,0x5D},
    RF_cal2_data[]   = {0x45,0x21,0xEF,0x2C,0x5A,0x42},
    Dem_cal_data[]   = {0x01},
    Dem_cal2_data[]  = {0x0B,0xDF,0x02};

void XN297L_Init(void)
{
    XN297L_WriteReg(XN297L_CMD_RST_FSPI, 0x5A); // Soft reset
    XN297L_WriteReg(XN297L_CMD_RST_FSPI, 0XA5);

    XN297L_WriteReg(XN297L_CMD_FLUSH_TX, 0);
    XN297L_WriteReg(XN297L_CMD_FLUSH_RX, 0);
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_STATUS, 0x70);       // Clear status flags
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_EN_AA, 0x3F);        // AutoAck on all pipes
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_EN_RXADDR, 0x3F);    // Enable all pipes (P0 ~ P5, bit0 ~ bit5)
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_SETUP_AW, XN297L_SETUP_AW_5BYTE); // Address width
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_RF_CH, 78);          // Channel 78, 2478M HZ
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_RX_PW_P0, XN297L_PLOAD_WIDTH ); // Payload width of P0
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_RX_PW_P1, XN297L_PLOAD_WIDTH ); // Payload width of P1
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_RX_PW_P2, XN297L_PLOAD_WIDTH ); // Payload width of P2
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_RX_PW_P3, XN297L_PLOAD_WIDTH ); // Payload width of P3
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_RX_PW_P4, XN297L_PLOAD_WIDTH ); // Payload width of P4
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_RX_PW_P5, XN297L_PLOAD_WIDTH ); // Payload width of P5

    XN297L_WriteFromBuf(XN297L_CMD_W_REGISTER | XN297L_REG_BB_CAL,    BB_cal_data,  sizeof(BB_cal_data));
    XN297L_WriteFromBuf(XN297L_CMD_W_REGISTER | XN297L_REG_RF_CAL2,   RF_cal2_data, sizeof(RF_cal2_data));
    XN297L_WriteFromBuf(XN297L_CMD_W_REGISTER | XN297L_REG_DEM_CAL,   Dem_cal_data, sizeof(Dem_cal_data));
    XN297L_WriteFromBuf(XN297L_CMD_W_REGISTER | XN297L_REG_RF_CAL,    RF_cal_data,  sizeof(RF_cal_data));
    XN297L_WriteFromBuf(XN297L_CMD_W_REGISTER | XN297L_REG_DEM_CAL2,  Dem_cal2_data,sizeof(Dem_cal2_data));
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_DYNPD, 0x00); // Dynamic payload width: off
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_RF_SETUP,  XN297L_RF_POWER_P_9|XN297L_RF_DR_1M); // 9dbm 1Mbps
    XN297L_WriteReg(XN297L_CMD_ACTIVATE, 0x73);

    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_SETUP_RETR, 0x10|0x05); // Retry interval 500μs, 5 times

    if(XN297L_PLOAD_WIDTH >32)
    {
        XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_FEATURE, XN297L_FEATURE_BIT5_CE_SOFT|XN297L_FEATURE_BIT43_DATA_64BYTE);
    }
    else
    {
        XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_FEATURE, XN297L_FEATURE_BIT5_CE_SOFT);
    }
}

數(shù)據(jù)發(fā)送函數(shù). 因?yàn)榍懊骈_(kāi)啟了重試和ACK, 這里做了一個(gè)等待發(fā)送結(jié)果的輪詢(xún)和超時(shí)判斷

uint8_t XN297L_TxData(uint8_t *ucPayload, uint8_t length)
{
    uint8_t y = 100, status = 0;
    XN297L_CE_HIGH();
    __NOP();
    XN297L_WriteFromBuf(XN297L_CMD_W_TX_PAYLOAD, ucPayload, length);
    // Retry until timeout
    while (y--)
    {
        LL_mDelay(1);
        status = XN297L_ReadStatus();
        // If TX successful or retry timeout, exit
        if ((status & (XN297L_FLAG_MAX_RT | XN297L_FLAG_TX_DS)) != 0)
        {
            //printf(" %d %02x\r\n", y, status);
            break;
        }
    }
    XN297L_WriteReg(XN297L_CMD_FLUSH_TX, 0);
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_STATUS, 0x70);
    XN297L_CE_LOW();
    return status;
}

數(shù)據(jù)接收. 因?yàn)榻邮帐褂玫氖禽喸?xún), 所以這里只是簡(jiǎn)單地判斷了接收狀態(tài), 在收到數(shù)據(jù)時(shí)讀取數(shù)據(jù).

uint8_t XN297L_DumpRxData(void)
{
    uint8_t status, rxplWidth;
    status = XN297L_ReadStatus();
    if (status & XN297L_FLAG_RX_DR)
    {
        XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_STATUS, status);
        rxplWidth = XN297L_ReadReg(XN297L_CMD_R_RX_PL_WID);
        XN297L_ReadToBuf(XN297L_CMD_R_RX_PAYLOAD, xbuf, rxplWidth);
    }
    return status;
}

完整代碼

XN297L 示例代碼的 GitHub 倉(cāng)庫(kù)地址: https://github.com/IOsetting/py32f0-template/tree/main/Examples/PY32F0xx/LL/GPIO/XN297LBW_Wireless

運(yùn)行測(cè)試

修改 main.c 中的模式設(shè)置, 0為接收, 1為發(fā)送, 分別寫(xiě)入至兩個(gè)PY32F002A開(kāi)發(fā)板, 觀察UART的輸出.

// 0:RX, 1:TX
#define XN297L_MODE 0

接收端在每次接收到數(shù)據(jù)時(shí), 輸出第1,2,31個(gè)字節(jié)的值; 發(fā)送端每發(fā)送255組數(shù)據(jù)(每組32字節(jié))后, 會(huì)顯示發(fā)送成功的個(gè)數(shù)(十六進(jìn)制), 這個(gè)輸出可以用于計(jì)算發(fā)送成功率, 以及發(fā)送速度.

硬件SPI方式

接線(xiàn)

接線(xiàn)方式使用4線(xiàn)制全雙工, PY32的MOSI和MISO都接到XN297LBW的DATA, 但是在MOSI(PA7)上串一個(gè)1K的電阻. 對(duì)于使用SPI協(xié)議的三線(xiàn)連接, 如果半雙工SPI有問(wèn)題, 都可以用這種接線(xiàn)試試全雙工方式通信. 從實(shí)際測(cè)試看, XN297LBW 支持這種接線(xiàn)方式.

PY32                XN297LBW SOP8
PA0   ------------> DATA/MOSI
PA7   ---> 1KR ---> DATA/MOSI
PA1   ------------> CLK/SCK
PA6   ------------> CSN/NSS

                    USB2TTL
PA2(TX) ----------> RX
PA3(RX) ----------> TX

代碼說(shuō)明

SPI接口的初始化. 注意SPI的時(shí)鐘頻率不要超過(guò)4MHz

/**
 * SPI1 Alternative Function Pins
 * SPI1_SCK:  PA1_AF0, PA2_AF10, PA5_AF0, PA9_AF10, PB3_AF0
 * SPI1_MISO: PA0_AF10, PA6_AF0, PA7_AF10, PA11_AF0, PA13_AF10, PB4_AF0
 * SPI1_MOSI: PA1_AF10, PA2_AF0, PA3_AF10, PA7_AF0, PA8_AF10, PA12_AF0, PB5_AF0
 * SPI1_NSS:  PA4_AF0, PA10_AF10, PA15_AF0, PB0_AF0, PF1_AF10, PF3_AF10
*/
static void APP_SPI_Config(void)
{
  LL_SPI_InitTypeDef SPI_InitStruct = {0};
  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  LL_APB1_GRP2_EnableClock(LL_APB1_GRP2_PERIPH_SPI1);

  // PA1 SCK
  GPIO_InitStruct.Pin = LL_GPIO_PIN_1;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_HIGH;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_UP;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_0;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);
  // PA0 MISO
  GPIO_InitStruct.Pin = LL_GPIO_PIN_0;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_10;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);
  // PA7 MOSI
  GPIO_InitStruct.Pin = LL_GPIO_PIN_7;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_0;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);
  /*
   * Full duplex mode, MOSI and MISO both connect to DATA,
   * Add one 1KR between MOSI and DATA
  */
  SPI_InitStruct.TransferDirection = LL_SPI_FULL_DUPLEX;
  SPI_InitStruct.Mode = LL_SPI_MODE_MASTER;
  SPI_InitStruct.DataWidth = LL_SPI_DATAWIDTH_8BIT;
  SPI_InitStruct.ClockPolarity = LL_SPI_POLARITY_LOW;
  SPI_InitStruct.ClockPhase = LL_SPI_PHASE_1EDGE;
  SPI_InitStruct.NSS = LL_SPI_NSS_SOFT;
  // SPI的時(shí)鐘頻率不要超過(guò)4MHz
  SPI_InitStruct.BaudRate = LL_SPI_BAUDRATEPRESCALER_DIV16;
  SPI_InitStruct.BitOrder = LL_SPI_MSB_FIRST;
  LL_SPI_Init(SPI1, &SPI_InitStruct);
  LL_SPI_Enable(SPI1);
}

硬件SPI方式的字節(jié)讀寫(xiě)

uint8_t SPI_TxRxByte(uint8_t data)
{
  uint8_t SPITimeout = 0xFF;
  /* Check the status of Transmit buffer Empty flag */
  while (READ_BIT(SPI1->SR, SPI_SR_TXE) == RESET)
  {
    if (SPITimeout-- == 0)
      return 0;
  }
  LL_SPI_TransmitData8(SPI1, data);
  SPITimeout = 0xFF;
  while (READ_BIT(SPI1->SR, SPI_SR_RXNE) == RESET)
  {
    if (SPITimeout-- == 0)
      return 0;
  }
  // Read from RX buffer
  return LL_SPI_ReceiveData8(SPI1);
}

對(duì)應(yīng)XN297L的命令讀寫(xiě)改造為調(diào)用硬件SPI讀寫(xiě)函數(shù)

uint8_t XN297L_WriteReg(uint8_t reg, uint8_t value)
{
    uint8_t reg_val;
    XN297L_CSN_LOW();
    SPI_TxRxByte(reg);
    reg_val = SPI_TxRxByte(value);
    XN297L_CSN_HIGH();
    return reg_val;
}

uint8_t XN297L_ReadReg(uint8_t reg)
{
    uint8_t reg_val;
    XN297L_CSN_LOW();
    SPI_TxRxByte(reg);
    reg_val = SPI_TxRxByte(XN297L_CMD_NOP);
    XN297L_CSN_HIGH();
    return reg_val;
}

完整代碼

XN297L 示例代碼的 GitHub 倉(cāng)庫(kù)地址: https://github.com/IOsetting/py32f0-template/tree/main/Examples/PY32F0xx/LL/SPI/XN297L_Wireless

運(yùn)行測(cè)試

和GPIO模擬方式的一樣, 修改 main.c 中的模式設(shè)置, 0為接收, 1為發(fā)送, 分別寫(xiě)入至兩個(gè)PY32F002A開(kāi)發(fā)板, 觀察UART的輸出.

// 0:RX, 1:TX
#define XN297L_MODE 0

利用FIFO隊(duì)列提升發(fā)送速度

在 NRF24L01 的使用中, 可以通過(guò) "直接寫(xiě)入TX FIFO -> 通過(guò) FLAG 觀察 TX FIFO 是否寫(xiě)滿(mǎn)判斷是繼續(xù)寫(xiě)入還是阻塞等待" 的方式提升發(fā)送速度. XN297L 的 TX FIFO 隊(duì)列包含兩組 32 個(gè)字節(jié), 也可以通過(guò)這種方式進(jìn)行加速.

相關(guān)的函數(shù)

ErrorStatus XN297L_TxFast(const uint8_t *ucPayload, uint8_t length)
{
    //Blocking only if FIFO is full. This will loop and block until TX is successful or fail
    while ((XN297L_ReadStatus() & XN297L_FLAG_TX_FULL)) {
        if (xn297l_state & XN297L_FLAG_MAX_RT) {
            return ERROR;
        }
    }
    XN297L_WriteFromBuf(XN297L_CMD_W_TX_PAYLOAD, ucPayload, length);
    XN297L_CE_HIGH();
    return SUCCESS;
}

// 用于 MAX_RT 狀態(tài)清除標(biāo)志位
void XN297L_ReuseTX(void)
{
    XN297L_WriteReg(XN297L_CMD_W_REGISTER | XN297L_REG_STATUS, XN297L_FLAG_MAX_RT); //Clear max retry flag
    XN297L_CE_LOW();
    XN297L_CE_HIGH();
}

使用方式: 在發(fā)送循環(huán)中調(diào)用 XN297L_TxFast() 進(jìn)行發(fā)送, 在遇到錯(cuò)誤時(shí), 用 XN297L_ReuseTX() 重置狀態(tài)

if (XN297L_TxFast(tmp, XN297L_PLOAD_WIDTH) == SUCCESS)
{
  j++;
}
else
{
  XN297L_ReuseTX();
}

從實(shí)際測(cè)試結(jié)果看, 用 XN297L_TxFast() 發(fā)送相比普通發(fā)送方式有10%的性能提升.文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-710704.html

到了這里，關(guān)于普冉PY32系列(八) GPIO模擬和硬件SPI方式驅(qū)動(dòng)無(wú)線(xiàn)收發(fā)芯片XN297LBW的文章就介紹完了。如果您還想了解更多內(nèi)容，請(qǐng)?jiān)谟疑辖撬阉鱐OY模板網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持TOY模板網(wǎng)！