TM4C123用硬件I2C读取mpu9250的问题

user5813287

看着库函数手册和以前在32上写I2C的步骤写了个初始化程序设备ID读出来0x00

下面是程序

void I2C_Init(void)
{
SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C3);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);

GPIOPinTypeI2C(GPIO_PORTD_BASE,GPIO_PIN_1);
GPIOPinTypeI2C(GPIO_PORTD_BASE,GPIO_PIN_0);
GPIOPinTypeI2CSCL(GPIO_PORTD_BASE, GPIO_PIN_0);
GPIOPinConfigure(GPIO_PD0_I2C3SCL);
GPIOPinConfigure(GPIO_PD1_I2C3SDA);

I2CMasterInitExpClk(I2C3_BASE, SysCtlClockGet(), true);
I2CMasterEnable(I2C3_BASE);
}

void MPU_Write_Byte(uint8_t addr,uint8_t reg,uint8_t data)
{
I2CMasterSlaveAddrSet(I2C3_BASE,addr,false);
I2CMasterDataPut(I2C3_BASE,reg);
I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_SEND_START);
while(I2CMasterBusy(I2C3_BASE));
I2CMasterDataPut(I2C3_BASE,data);
I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_SEND_CONT);
while(I2CMasterBusy(I2C3_BASE));
I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_SEND_FINISH);
}

uint8_t MPU_Read_Byte(uint8_t addr,uint8_t reg)
{
uint32_t raw_res;
uint8_t res;
I2CMasterSlaveAddrSet(I2C3_BASE,addr,false);
I2CMasterDataPut(I2C3_BASE,reg);
I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_SEND_START);
while(I2CMasterBusy(I2C3_BASE));
I2CMasterSlaveAddrSet(I2C3_BASE,addr,true);
I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_SINGLE_RECEIVE);
while(I2CMasterBusy(I2C3_BASE));
raw_res=I2CMasterDataGet(I2C3_BASE);
res=(uint8_t)(raw_res>>24);
return res;
}

void MPU_Read_Len(uint8_t addr,uint8_t reg,uint8_t len,uint8_t *buf)
{
uint8_t i;
uint32_t raw_res;
uint8_t res;
I2CMasterSlaveAddrSet(I2C3_BASE,addr,false);
I2CMasterDataPut(I2C3_BASE,reg);
I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_SEND_START);
while(I2CMasterBusy(I2C3_BASE));
I2CMasterSlaveAddrSet(I2C3_BASE,addr,true);
I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_RECEIVE_START);
while(I2CMasterBusy(I2C3_BASE));
for(i=0;i<len;i++)
{
  I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_RECEIVE_CONT);
   while(I2CMasterBusy(I2C3_BASE));
    raw_res=I2CMasterDataGet(I2C3_BASE);
    res=(uint8_t)(raw_res>>24);
   buf++;
}
I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_RECEIVE_FINISH);
}

下面是初始化程序

uint8_t MPU9250_Init(void)
{
uint8_t res=0;
I2C_Init();
MPU_Write_Byte(MPU9250_ADDR,MPU_PWR_MGMT1_REG,0X80);
delay_Nms(200);
MPU_Write_Byte(MPU9250_ADDR,MPU_PWR_MGMT1_REG,0X00);
MPU_Set_Gyro_Fsr(3); //ÍÓÂÝÒÇ´«¸ÐÆ÷,¡À2000dps
MPU_Set_LPF(42);
MPU_Set_Accel_Fsr(0);            //¼ÓËÙ¶È´«¸ÐÆ÷,¡À2g
MPU_Set_Rate(500);             //ÉèÖÃ²ÉÑùÂÊ500Hz
MPU_Write_Byte(MPU9250_ADDR,MPU_INT_EN_REG,0X00);   //¹Ø±ÕËùÓÐÖÐ¶Ï
MPU_Write_Byte(MPU9250_ADDR,MPU_USER_CTRL_REG,0X00);//I2CÖ÷Ä£Ê½¹Ø±Õ
MPU_Write_Byte(MPU9250_ADDR,MPU_FIFO_EN_REG,0XFF);
MPU_Write_Byte(MPU9250_ADDR,MPU_INTBP_CFG_REG,0X82);//INTÒý½ÅµÍµçÆ½ÓÐÐ§£¬¿ªÆôbypassÄ£Ê½£¬¿ÉÒÔÖ±½Ó¶ÁÈ¡´ÅÁ¦¼Æ
res=MPU_Read_Byte(MPU9250_ADDR,MPU_DEVICE_ID_REG|0x80); //¶ÁÈ¡MPU6500µÄID
if(res==MPU6500_ID) //Æ÷¼þIDÕýÈ·
{
   MPU_Write_Byte(MPU9250_ADDR,MPU_PWR_MGMT1_REG,0X01); //ÉèÖÃCLKSEL,PLL XÖáÎª²Î¿¼
   MPU_Write_Byte(MPU9250_ADDR,MPU_PWR_MGMT2_REG,0X00); //¼ÓËÙ¶ÈÓëÍÓÂÝÒÇ¶¼¹¤×÷
   MPU_Set_Rate(500);             //ÉèÖÃ²ÉÑùÂÊÎª500Hz
}else return 1;

res=MPU_Read_Byte(AK8963_ADDR,MAG_WIA); //¶ÁÈ¡AK8963 ID
if(res==AK8963_ID)
{
MPU_Write_Byte(AK8963_ADDR,MAG_CNTL1,0X11); //ÉèÖÃAK8963Îªµ¥´Î²âÁ¿Ä£Ê½
}else return 1;

return 0;
} 设备ID读不出来

7 年多前

0 user5813287 7 年多前

Intellectual 310 points

好吧其实读出来了只是我数据类型转换不正确现在是能读出9轴数据了但数据一直不变请教下大佬们

0 xyz549040622 7 年多前回复 user5813287

Guru 65885 points

数据一直不变，是指什么数据呢？MPU6500还是AK8963？ID正确，说明时序OK，读不到数据不正常呀？

0 da qin zheng sheng 7 年多前回复 user5813287

Guru 42895 points

正确初始化参数后芯片才能正常工作的。

0 da qin zheng sheng 7 年多前

Guru 42895 points

内部的磁力计i2c地址不一样，需要
旁路设置？

0 xyz549040622 7 年多前回复 da qin zheng sheng

Guru 65885 points

能读到ID，说明初始化已经成功了吧。

0 user5813287 7 年多前回复 xyz549040622

Intellectual 310 points

设备ID有时能读到有时失去总线控制

0 xyz549040622 7 年多前回复 user5813287

Guru 65885 points

参考另一个帖子的说法，可能是I2C的驱动能力不够，确保上拉，可能是距离远了，降低速率试试。

0 user5813287 7 年多前回复 xyz549040622

Intellectual 310 points

哪篇帖子啊给个链接嘛

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TM4C123用硬件I2C读取mpu9250的问题