[原创] 基于PSOC6开发板模拟I2C 解X-NUCLEO-IKS01A3的STTS751;

DavidZH 2019-7-27 21:25 楼主

周末终于有时间来研究下X-NUCLEO-IKS01A3，先从简单的开始，STTS751 是ST的I2C接口的数字温度传感器；

硬件： STTS751 是接的I2C1，地址0x94，电压是不常见的2.5V，如果是单独用的话，还得加LDO；

软件：

I2C 底层协议：开始，结束，发数据和接受数据，ACK, NACK; 具体要看怎么自己怎么写；

void I2C_Start(void);
void I2C_Stop(void);

uint8_t I2C_Send_Byte(uint8_t oneByte);   
uint8_t I2C_Read_Byte(uint8_t bLSByte);

大概的流程图很简单，写器件地址，写寄存器地址和读数据即可；

uint8_t  STTS751_Write_Cmd(uint8_t SlaveAddress, uint8_t RegAddress,  uint8_t Cmd)
{
     uint8_t succ, stime=0;
    
     I2C_Start();
     succ = I2C_Send_Byte(SlaveAddress & 0xfe);
     while((succ !=1) &&(stime <3))
    {
        I2C_Stop();
        I2C_Start();
        succ = I2C_Send_Byte(SlaveAddress & 0xfe);
        stime++;
    }
    succ = I2C_Send_Byte(RegAddress);
    succ = I2C_Send_Byte(Cmd);
    I2C_Stop(); 
    return succ;
}

 uint8_t STTS751_Read_Date(uint8_t SlaveAddress, uint8_t RegAddress)
{
    uint8_t recvDate;
    uint8_t succ, stime=0;
    
    I2C_Start();
    succ = I2C_Send_Byte(SlaveAddress & 0xfe);
    while((succ !=1)&&(stime<3))
    {
        I2C_Stop();
        I2C_Start();
        succ = I2C_Send_Byte(SlaveAddress & 0xfe);  //写
        stime++;
    }
    I2C_Send_Byte(RegAddress);
    
    I2C_Start();
    I2C_Send_Byte(SlaveAddress | 0x01);  //读
    recvDate = I2C_Read_Byte(1);   //NACK
    I2C_Stop();
    return recvDate;
}

从原理图上看给的地址是0x94;

Main 函数如下：

 int main(void)
{
    uint8_t PID;
    uint8_t TempH, TempL;
    double Temp; 
   
    Cy_SCB_UART_Init(Uart_Printf_HW, &Uart_Printf_config, &Uart_Printf_context);
    Cy_SCB_UART_Enable(Uart_Printf_HW);
    

    __enable_irq(); /* Enable global interrupts. */
    
    for(;;)
    {
        while(1)
        {
           PID =STTS751_Read_Date(0x94, 0xfe);
           TempH = STTS751_Read_Date(0x94, 0x00);
           printf("TempH = %d \r\n", TempH);
           printf("PID = %X \r\n", PID);
       }
   }
}

有个Production ID,还有一个温度值， 32℃，好热啊！！！