我拿到的開(kāi)發(fā)板實(shí)際板載的MCU是GD32F310G8，QFN28pin封裝，基于ARM CORTEX M4內(nèi)核，主頻72MHz，芯片內(nèi)置64KB flash，8KB SRAM，兩路I2C外設(shè)。

本次試用目的是利用GD32F310的I2C0實(shí)現(xiàn)對(duì)HDC1080的初始化及讀取環(huán)境溫濕度，并利用UART口在電腦上顯示出來(lái)。

1、新建工程

①首先建立一個(gè)新的項(xiàng)目文件夾，并在此文件夾下建立對(duì)應(yīng)子文件夾，我建立的文件如下圖所示，這個(gè)依個(gè)人習(xí)慣會(huì)有不同：

② Document文件夾中存放對(duì)項(xiàng)目的說(shuō)明文件readme.txt；將系統(tǒng)支持包中的GD32F3x0_Firmware_Library_V2.2.0/Firmware文件夾中的內(nèi)容復(fù)制到Libraries文件夾中；Listing/Output文件夾用于存放項(xiàng)目編譯時(shí)生成的目標(biāo)文件及l(fā)ist文件，在MDK的魔術(shù)棒中進(jìn)行設(shè)置路徑；users文件夾中存放main文件及我們自已寫(xiě)的代碼；Project文件夾中存放MDK項(xiàng)目文件；

③打開(kāi)MDK keil5，首先要先導(dǎo)入GD32F310G文件支持包。

④建立新的項(xiàng)目，選擇所使用的ＭＣＵ，我們選擇GD32F330G8，如下圖所示

⑤新項(xiàng)目中建立如下文件組，并導(dǎo)入啟動(dòng)文件和外設(shè)支持包。

⑥點(diǎn)擊魔術(shù)棒工具進(jìn)行項(xiàng)目設(shè)置。在C/C++選項(xiàng)中添加include文件路徑；

⑦點(diǎn)擊Debug選項(xiàng)進(jìn)行GDLink的設(shè)置，要選擇CMSIS_DAP Debugger，并將Reset and Run打勾。

⑧這樣整個(gè)項(xiàng)目的配置基本就結(jié)束了，可以在main.c文件中建立一個(gè)空循環(huán)，編譯測(cè)試項(xiàng)目建立是否正確無(wú)誤。

2、硬件映射

硬件映射的目的是按目前的硬件連接建立.h文件，如下圖所示：

因此基于開(kāi)發(fā)板I2C0采用的是PB6/PB7引腳，因?yàn)樾枰蛴∽x出的值，UART0使用的是PA9/PA10引腳。

3、編寫(xiě)代碼

①UART0初始化和printf函數(shù)重定向：

void UART_TypeInit(void)
{
    gpio_deinit(UART0_GPIO_PORT);
    usart_deinit(USART0);
    rcu_periph_clock_enable(UART0_GPIO_PORT_CLK);
    gpio_mode_set(UART0_GPIO_PORT,GPIO_MODE_AF,GPIO_PUPD_NONE,UART0_TX_PIN | UART0_RX_PIN);
    gpio_output_options_set(UART0_GPIO_PORT,GPIO_OTYPE_OD,GPIO_OSPEED_MAX,UART0_TX_PIN | UART0_RX_PIN);
    gpio_af_set(UART0_GPIO_PORT,GPIO_AF_1,UART0_TX_PIN | UART0_RX_PIN);
    
    rcu_periph_clock_enable(UART0_CLK);
    usart_baudrate_set(USART0,UART0_Baudrate);
    usart_parity_config(USART0,USART_PM_NONE);
    usart_word_length_set(USART0,USART_WL_8BIT);
    usart_stop_bit_set(USART0,USART_STB_1BIT);
    usart_enable(USART0);
    usart_transmit_config(USART0,USART_TRANSMIT_ENABLE);
    usart_receive_config(USART0,USART_RECEIVE_ENABLE);
}

/* retarget the C library printf function to the USART */
int fputc(int ch, FILE *f)
{
    usart_data_transmit(USART0, (uint8_t)ch);
    while(RESET == usart_flag_get(USART0,USART_FLAG_TBE)); 
        
    return ch;
}

②I2C0外設(shè)初始化：

void I2C0_TypeInit(void)
{
    gpio_deinit(I2C0_GPIO_PORT);
    i2c_deinit(I2C0);
    rcu_periph_clock_enable(I2C0_GPIO_PORT_CLK);
    gpio_mode_set(I2C0_GPIO_PORT,GPIO_MODE_AF,GPIO_PUPD_NONE,I2C0_SCL_PIN | I2C0_SDA_PIN);
    gpio_output_options_set(I2C0_GPIO_PORT,GPIO_OTYPE_OD,GPIO_OSPEED_MAX,I2C0_SCL_PIN | I2C0_SDA_PIN);
    gpio_af_set(I2C0_GPIO_PORT,GPIO_AF_1,I2C0_SCL_PIN | I2C0_SDA_PIN);
    
    rcu_periph_clock_enable(I2C0_CLK);
    i2c_clock_config(I2C0,I2C0_Frequence,I2C_DTCY_2);
    i2c_mode_addr_config(I2C0,I2C_I2CMODE_ENABLE,I2C_ADDFORMAT_7BITS,I2C0_OWN_Address);
    i2c_enable(I2C0);
    i2c_ack_config(I2C0,I2C_ACK_ENABLE);
}

③讀寄存器操作：

void  I2C0_Register_Read(uint8_t* B_buffer, uint8_t read_address,uint16_t number_of_byte)
{
     /* wait until I2C bus is idle */
    while(i2c_flag_get(I2C0, I2C_FLAG_I2CBSY));

    if(2 == number_of_byte){
        i2c_ackpos_config(I2C0,I2C_ACKPOS_NEXT);
    }
    
    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C0);
    
    /* wait until SBSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_SBSEND));
    
    /* send slave address to I2C bus */
    i2c_master_addressing(I2C0, HDC1080_Addr, I2C_TRANSMITTER);
    
    /* wait until ADDSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND));
    
    /* clear the ADDSEND bit */
    i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
    
    /* wait until the transmit data buffer is empty */
    while(SET != i2c_flag_get( I2C0 , I2C_FLAG_TBE));

    /* enable I2C0*/
    i2c_enable(I2C0);
    
    /* send the EEPROM's internal address to write to */
    i2c_data_transmit(I2C0, read_address);  
    
    /* wait until BTC bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_BTC));
        
        delay_1ms(20);
    
    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C0);
    
    /* wait until SBSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_SBSEND));
    
    /* send slave address to I2C bus */
    i2c_master_addressing(I2C0, HDC1080_Addr, I2C_RECEIVER);

    if(number_of_byte < 3){
        /* disable acknowledge */
        i2c_ack_config(I2C0,I2C_ACK_DISABLE);
    }
    
    /* wait until ADDSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND));
    
    /* clear the ADDSEND bit */
    i2c_flag_clear(I2C0,I2C_FLAG_ADDSEND);
    
    if(1 == number_of_byte){
        /* send a stop condition to I2C bus */
        i2c_stop_on_bus(I2C0);
    }
    
    /* while there is data to be read */
    while(number_of_byte){
        if(3 == number_of_byte){
            /* wait until BTC bit is set */
            while(!i2c_flag_get(I2C0, I2C_FLAG_BTC));

            /* disable acknowledge */
            i2c_ack_config(I2C0,I2C_ACK_DISABLE);
        }
        if(2 == number_of_byte){
            /* wait until BTC bit is set */
            while(!i2c_flag_get(I2C0, I2C_FLAG_BTC));
            
            /* send a stop condition to I2C bus */
            i2c_stop_on_bus(I2C0);
        }
        
                delay_1ms(1);
        /* wait until the RBNE bit is set and clear it */
        if(i2c_flag_get(I2C0, I2C_FLAG_RBNE)){
            /* read a byte from the EEPROM */
            *B_buffer = i2c_data_receive(I2C0);
            
            /* point to the next location where the byte read will be saved */
            B_buffer++; 
            
            /* decrement the read bytes counter */
            number_of_byte--;
        } 
    }
    
    /* wait until the stop condition is finished */
    while(I2C_CTL0(I2C0)&0x0200);
    
    /* enable acknowledge */
    i2c_ack_config(I2C0, I2C_ACK_ENABLE);

    i2c_ackpos_config(I2C0, I2C_ACKPOS_CURRENT);
}

④寫(xiě)寄存器操作：

void I2C0_Byte_Write(uint8_t* P_buffer, uint8_t write_address)
{
    uint8_t i;
    /* wait until I2C bus is idle */
    while(i2c_flag_get(I2C0, I2C_FLAG_I2CBSY));

    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C0);

    /* wait until SBSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_SBSEND));

    /* send slave address to I2C bus */
    i2c_master_addressing(I2C0, HDC1080_Addr, I2C_TRANSMITTER);

    /* wait until ADDSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND));

    /* clear the ADDSEND bit */
    i2c_flag_clear(I2C0,I2C_FLAG_ADDSEND);

    /* wait until the transmit data buffer is empty */
    while(SET != i2c_flag_get(I2C0, I2C_FLAG_TBE));

    /* send the EEPROM's internal address to write to : only one byte address */
    i2c_data_transmit(I2C0, write_address);

    /* wait until BTC bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_BTC));
    
    for(i=0;i<2;i++)
    {

        /* send the byte to be written */
        i2c_data_transmit(I2C0, *(P_buffer+i)); 

        /* wait until BTC bit is set */
        while(!i2c_flag_get(I2C0, I2C_FLAG_TBE));
    
    }

    /* send a stop condition to I2C bus */
    i2c_stop_on_bus(I2C0);

    /* wait until the stop condition is finished */
    while(I2C_CTL0(I2C0)&0x0200);
}

⑤對(duì)HDC1080進(jìn)行初始化并讀取其ID：

void HDC1080_Init(void)
{
    uint8_t    IDBuffer[2]={0};
    uint8_t InitSetup[2]={0x90,0x00};
    uint32_t SID[3]={0},MID=0,DID=0;
    I2C0_Byte_Write(InitSetup,CONFIGURATION);
    delay_1ms(20);
    
    I2C0_Register_Read(IDBuffer,DEVICE_ID,2);
    DID = (((uint32_t)IDBuffer[0])<<8 | IDBuffer[1]);
    printf("The DeviceID is 0x%x\n\r",DID);
    I2C0_Register_Read(IDBuffer,MANUFACTURE_ID,2);
    MID = ((uint16_t) IDBuffer[0]<<8 | IDBuffer[1]);
    printf("The ManufactureID is 0x%x\n\r",MID);
    I2C0_Register_Read(IDBuffer,FIRST_SID,2);
    SID[0] = ((uint16_t) IDBuffer[0]<<8 | IDBuffer[1]); 
    I2C0_Register_Read(IDBuffer,MID_SID,2);
    SID[1] = ((uint16_t) IDBuffer[0]<<8 | IDBuffer[1]);
    I2C0_Register_Read(IDBuffer,LAST_SID,2);
    SID[2] = ((uint16_t) IDBuffer[0]<<8 | IDBuffer[1]);
    printf("The First bytes of the serial ID of the part is 0x%x\n\r",SID[0]);
    printf("The MID bytes of the serial ID of the part is 0x%x\n\r",SID[1]);
    printf("The Last bytes of the serial ID of the part is 0x%x\n\r",SID[2]);
    printf("\n\r");
}

⑥讀取溫濕度值并轉(zhuǎn)換成十進(jìn)制顯示：

void readSensor(void)
{
  //holds 2 bytes of data from I2C Line
  uint8_t Buffer_Byte[2];

  //holds the total contents of the temp register
  uint16_t temp,hum;

  //holds the total contents of the humidity register
  double temperature=0,humidity=0 ;
    
    I2C0_Register_Read(Buffer_Byte,T_MEASUREMENT,2);
    temp = (((uint32_t)Buffer_Byte[0])<<8 | Buffer_Byte[1]);
    temperature = (double)(temp)/(65536)*165-40;
    printf("The temperature is %.2f\n\r",temperature);
    
    I2C0_Register_Read(Buffer_Byte,RH_MEASUREMENT,2);
    hum = (((uint32_t)Buffer_Byte[0])<<8 | Buffer_Byte[1]);
    humidity = (double)(hum)/(65536)*100;
    printf("The humidity is %.2f%%\n\r",humidity);    
}

⑦main函數(shù)：

/*!
    \brief      main function
    \param[in]  none
    \param[out] none
    \retval     none
*/
int main(void)
{
    /* configure periphreal */
  systick_Init();
    LED_TypeInit();
//    NVIC_config();
//    KEY_EXTI_TypeInit();
    UART_TypeInit();
    I2C0_TypeInit();
    printf("**********DEMO START**********\n\r");
    printf("******************************\n\r");
    HDC1080_Init();

    while(1) 
    {
        readSensor();
        delay_1ms(1000);
    }
}

4、編譯下載

①Build項(xiàng)目文件：

②沒(méi)有錯(cuò)誤，直接下載到開(kāi)發(fā)板中，可以打開(kāi)串口看到讀出溫濕度每隔1S讀一次并打印出來(lái)，與環(huán)境溫度計(jì)比較取值還是比較準(zhǔn)確的。

5、試用總結(jié)

GD32F310G8芯片采用4x4 QFN28封裝，結(jié)構(gòu)可以設(shè)計(jì)相當(dāng)緊湊，軟件開(kāi)發(fā)資源也是很豐富，雖然功能不算特別強(qiáng)大，但主流的外設(shè)基本都有囊括，在目前國(guó)產(chǎn)替代的大環(huán)境之下，應(yīng)用前景還是相當(dāng)廣泛的。