使用stm32f103c8t6和ZE08甲醛传感器建立联系，同时使用SPI通信的OLED模块显示甲醛浓度，传感器接PB10和11，OLED接PA5和7传输数据，程序设计

以下是使用stm32f103c8t6和ZE08甲醛传感器建立联系，同时使用SPI通信的OLED模块显示甲醛浓度的程序设计：

#include "stm32f10x.h"

#define OLED_DC_Pin GPIO_Pin_5
#define OLED_DC_Port GPIOA
#define OLED_CS_Pin GPIO_Pin_7
#define OLED_CS_Port GPIOA

void OLED_GPIO_init(void);
void OLED_write_cmd(unsigned char command);
void OLED_write_data(unsigned char data);
void OLED_init(void);
void OLED_show_str(unsigned char x, unsigned char y, unsigned char *str);

void SPI1_init(void);
void SPI1_send_byte(unsigned char byte);
unsigned char SPI1_receive_byte(void);

void USART2_init(void);
void USART2_send_byte(unsigned char byte);

void delay_ms(unsigned int ms);

int main(void)
{
    unsigned char buf[10];
    float concentration;
    unsigned char str[10];

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB, ENABLE);

    OLED_GPIO_init();
    OLED_init();

    SPI1_init();

    USART2_init();

    while(1)
    {
        GPIO_ResetBits(GPIOB, GPIO_Pin_10);
        delay_ms(1000);
        SPI1_send_byte(0xFF);
        buf[0] = SPI1_receive_byte();
        buf[1] = SPI1_receive_byte();
        buf[2] = SPI1_receive_byte();
        buf[3] = SPI1_receive_byte();
        GPIO_SetBits(GPIOB, GPIO_Pin_10);

        concentration = ((buf[0] * 256) + buf[1]) / 1000.0;
        sprintf((char *)str, "%.2f mg/m3", concentration);
        OLED_show_str(0, 1, str);

        USART2_send_byte(buf[0]);
        USART2_send_byte(buf[1]);
        USART2_send_byte(buf[2]);
        USART2_send_byte(buf[3]);
        USART2_send_byte('\n');

        delay_ms(5000);
    }
}

void OLED_GPIO_init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    GPIO_InitStructure.GPIO_Pin = OLED_DC_Pin | OLED_CS_Pin;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
}

void OLED_write_cmd(unsigned char command)
{
    GPIO_ResetBits(OLED_DC_Port, OLED_DC_Pin);
    GPIO_ResetBits(OLED_CS_Port, OLED_CS_Pin);
    SPI1_send_byte(command);
    GPIO_SetBits(OLED_CS_Port, OLED_CS_Pin);
}

void OLED_write_data(unsigned char data)
{
    GPIO_SetBits(OLED_DC_Port, OLED_DC_Pin);
    GPIO_ResetBits(OLED_CS_Port, OLED_CS_Pin);
    SPI1_send_byte(data);
    GPIO_SetBits(OLED_CS_Port, OLED_CS_Pin);
}

void OLED_init(void)
{
    OLED_write_cmd(0xAE); // display off
    OLED_write_cmd(0x20); // addressing mode
    OLED_write_cmd(0x10); // horizontal addressing mode
    OLED_write_cmd(0xb0); // set page start address
    OLED_write_cmd(0xc8); // set COM output scan direction
    OLED_write_cmd(0x00); // set low column address
    OLED_write_cmd(0x10); // set high column address
    OLED_write_cmd(0x40); // set start line address
    OLED_write_cmd(0x81); // set contrast control register
    OLED_write_cmd(0xff); // set contrast to maximum
    OLED_write_cmd(0xa1); // set segment re-map 95 to 0
    OLED_write_cmd(0xa6); // set normal display
    OLED_write_cmd(0xa8); // set multiplex ratio
    OLED_write_cmd(0x3f); // 1/64 duty
    OLED_write_cmd(0xa4); // display all on/resume to display
    OLED_write_cmd(0xd3); // set display offset
    OLED_write_cmd(0x00); // not offset
    OLED_write_cmd(0xd5); // set display clock divide ratio/oscillator frequency
    OLED_write_cmd(0xf0); // set divide ratio
    OLED_write_cmd(0xd9); // set pre-charge period
    OLED_write_cmd(0x22); // set pre-charge period
    OLED_write_cmd(0xda); // set COM pins hardware configuration
    OLED_write_cmd(0x12);
    OLED_write_cmd(0xdb); // set vcomh
    OLED_write_cmd(0x20); // 0.77xVcc
    OLED_write_cmd(0x8d); // set charge pump enable/disable
    OLED_write_cmd(0x14); // enable charge pump
    OLED_write_cmd(0xaf); // turn on oled panel
}

void OLED_show_str(unsigned char x, unsigned char y, unsigned char *str)
{
    unsigned char i, j;

    for(i = 0; str[i] != '\0'; i++)
    {
        for(j = 0; j < 6; j++)
        {
            OLED_write_data(F6x8[(str[i] - 32) * 6 + j]);
        }
    }
}

void SPI1_init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    SPI_InitTypeDef SPI_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
    SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
    SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
    SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
    SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
    SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
    SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;
    SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
    SPI_Init(SPI1, &SPI_InitStructure);

    SPI_Cmd(SPI1, ENABLE);
}

void SPI1_send_byte(unsigned char byte)
{
    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
    SPI_I2S_SendData(SPI1, byte);
    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
    SPI_I2S_ReceiveData(SPI1);
}

unsigned char SPI1_receive_byte(void)
{
    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
    SPI_I2S_SendData(SPI1, 0xFF);
    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
    return SPI_I2S_ReceiveData(SPI1);
}

void USART2_init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    USART_InitStructure.USART_BaudRate = 115200;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Tx;
    USART_Init(USART2, &USART_InitStructure);

    USART_Cmd(USART2, ENABLE);
}

void USART2_send_byte(unsigned char byte)
{
    while(USART_GetFlagStatus(USART2, USART_FLAG_TC) == RESET);
    USART_SendData(USART2, byte);
}

void delay_ms(unsigned int ms)
{
    unsigned int i, j;

    for(i = 0; i < ms; i++)
    {
        for(j = 0; j < 1000; j++);
    }
}

注意事项：

1. 在使用 SPI 通信时，需要先拉低从机的片选引脚（本例中为 PB10），并在传输完数据后再拉高。
2. OLED 模块使用的是 I2C 通信，本例中未使用 I2C，而是采用了自己定义的一组字符库（F6x8），因此 OLED 模块只能显示英文字母和数字，并且是单色的。如果需要显示中文或多种颜色，需要使用 I2C 通信，并且设置不同的字符库和颜色值。