【STM32】STM32学习笔记-硬件I2C读写MPU6050(35)

00. 目录

01. I2C简介

I2C(Inter－Integrated Circuit)总线是一种由NXP（原PHILIPS）公司开发的两线式串行总线，用于连接微控制器及其外围设备。多用于主控制器和从器件间的主从通信，在小数据量场合使用，传输距离短，任意时刻只能有一个主机等特性。

串行的 8 位双向数据传输位速率在标准模式下可达 100kbit/s，快速模式下可达 400kbit/s，高速模式下可达 3.4Mbit/s。

I2C是一个多主机的总线，每个设备既可以当主控器或被控器，又可作为发送器或接收器，一条总线上可以有多个主机，但同一时刻只允许一个主机工作。

02. MPU6050

?MPU6050是一个6轴姿态传感器，可以测量芯片自身X、Y、Z轴的加速度、角速度参数，通过数据融合，可进一步得到姿态角，常应用于平衡车、飞行器等需要检测自身姿态的场景

?3轴加速度计（Accelerometer）：测量X、Y、Z轴的加速度

?3轴陀螺仪传感器（Gyroscope）：测量X、Y、Z轴的角速度

03. I2C相关API

3.1 I2C_Init

/**
  * @brief  Initializes the I2Cx peripheral according to the specified 
  *   parameters in the I2C_InitStruct.
  * @param  I2Cx: where x can be 1 or 2 to select the I2C peripheral.
  * @param  I2C_InitStruct: pointer to a I2C_InitTypeDef structure that
  *   contains the configuration information for the specified I2C peripheral.
  * @retval None
  */
void I2C_Init(I2C_TypeDef* I2Cx, I2C_InitTypeDef* I2C_InitStruct)
功能:
	根据 I2C_InitStruct 中指定的参数初始化外设 I2Cx 寄存器
参数:
   I2Cx：x 可以是 1 或者 2，来选择 I2C 外设
   I2C_InitStruct：指向结构 I2C_InitTypeDef 的指针，包含了外设 GPIO 的配置信息
返回值:
	无      

3.2 I2C_InitTypeDef

/** 
  * @brief  I2C Init structure definition  
  */

typedef struct
{
  uint32_t I2C_ClockSpeed;          /*!< Specifies the clock frequency.
                                         This parameter must be set to a value lower than 400kHz */
  uint16_t I2C_Mode;                /*!< Specifies the I2C mode.
                                         This parameter can be a value of @ref I2C_mode */
  uint16_t I2C_DutyCycle;           /*!< Specifies the I2C fast mode duty cycle.
                                         This parameter can be a value of @ref I2C_duty_cycle_in_fast_mode */
  uint16_t I2C_OwnAddress1;         /*!< Specifies the first device own address.
                                         This parameter can be a 7-bit or 10-bit address. */
  uint16_t I2C_Ack;                 /*!< Enables or disables the acknowledgement.
                                         This parameter can be a value of @ref I2C_acknowledgement */
  uint16_t I2C_AcknowledgedAddress; /*!< Specifies if 7-bit or 10-bit address is acknowledged.
                                         This parameter can be a value of @ref I2C_acknowledged_address */
}I2C_InitTypeDef;

I2C_Mode

/** @defgroup I2C_mode 
  * @{
  */

#define I2C_Mode_I2C                    ((uint16_t)0x0000)
#define I2C_Mode_SMBusDevice            ((uint16_t)0x0002)  
#define I2C_Mode_SMBusHost              ((uint16_t)0x000A)

I2C_DutyCycle

/** @defgroup I2C_duty_cycle_in_fast_mode 
  * @{
  */

#define I2C_DutyCycle_16_9              ((uint16_t)0x4000) /*!< I2C fast mode Tlow/Thigh = 16/9 */
#define I2C_DutyCycle_2                 ((uint16_t)0xBFFF) /*!< I2C fast mode Tlow/Thigh = 2 */

I2C_OwnAddress1

I2C_Ack

/** @defgroup I2C_acknowledgement
  * @{
  */

#define I2C_Ack_Enable                  ((uint16_t)0x0400)
#define I2C_Ack_Disable                 ((uint16_t)0x0000)

I2C_AcknowledgedAddress

/** @defgroup I2C_acknowledged_address 
  * @{
  */

#define I2C_AcknowledgedAddress_7bit    ((uint16_t)0x4000)
#define I2C_AcknowledgedAddress_10bit   ((uint16_t)0xC000)

3.3 I2C_Cmd

/**
  * @brief  Enables or disables the specified I2C peripheral.
  * @param  I2Cx: where x can be 1 or 2 to select the I2C peripheral.
  * @param  NewState: new state of the I2Cx peripheral. 
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void I2C_Cmd(I2C_TypeDef* I2Cx, FunctionalState NewState)
功能:
	使能或者失能 I2C 外设
参数:
   I2Cx：x 可以是 1 或者 2，来选择 I2C 外设
   NewState: 外设 I2Cx 的新状态,这个参数可以取：ENABLE 或者 DISABLE
返回值:
	无       
    

3.4 I2C_GenerateSTART

/**
  * @brief  Generates I2Cx communication START condition.
  * @param  I2Cx: where x can be 1 or 2 to select the I2C peripheral.
  * @param  NewState: new state of the I2C START condition generation.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None.
  */
void I2C_GenerateSTART(I2C_TypeDef* I2Cx, FunctionalState NewState)
功能:
	产生 I2Cx 传输 START 条件
参数:
   I2Cx：x 可以是 1 或者 2，来选择 I2C 外设
   NewState: I2Cx START 条件的新状态, 这个参数可以取：ENABLE 或者 DISABLE
返回值:
	无      
    
    

3.5 I2C_GenerateSTOP

/**
  * @brief  Generates I2Cx communication STOP condition.
  * @param  I2Cx: where x can be 1 or 2 to select the I2C peripheral.
  * @param  NewState: new state of the I2C STOP condition generation.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None.
  */
void I2C_GenerateSTOP(I2C_TypeDef* I2Cx, FunctionalState NewState)
功能:
	产生 I2Cx 传输 STOP 条件
参数:
   I2Cx：x 可以是 1 或者 2，来选择 I2C 外设
   NewState: I2Cx STOP 条件的新状态, 这个参数可以取：ENABLE 或者 DISABLE
返回值:
	无         
    

3.6 I2C_AcknowledgeConfig

/**
  * @brief  Enables or disables the specified I2C acknowledge feature.
  * @param  I2Cx: where x can be 1 or 2 to select the I2C peripheral.
  * @param  NewState: new state of the I2C Acknowledgement.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None.
  */
void I2C_AcknowledgeConfig(I2C_TypeDef* I2Cx, FunctionalState NewState)
功能:
	使能或者失能指定 I2C 的应答功能
参数:
   I2Cx：x 可以是 1 或者 2，来选择 I2C 外设
   NewState: I2Cx 应答的新状态, 这个参数可以取：ENABLE 或者 DISABLE
返回值:
	无      
    

3.7 I2C_SendData

/**
  * @brief  Sends a data byte through the I2Cx peripheral.
  * @param  I2Cx: where x can be 1 or 2 to select the I2C peripheral.
  * @param  Data: Byte to be transmitted..
  * @retval None
  */
void I2C_SendData(I2C_TypeDef* I2Cx, uint8_t Data)
功能:
	通过外设 I2Cx 发送一个数据
参数:
   I2Cx：x 可以是 1 或者 2，来选择 I2C 外设
   Data: 待发送的数据
返回值:
	无        
    

3.8 I2C_ReceiveData

/**
  * @brief  Returns the most recent received data by the I2Cx peripheral.
  * @param  I2Cx: where x can be 1 or 2 to select the I2C peripheral.
  * @retval The value of the received data.
  */
uint8_t I2C_ReceiveData(I2C_TypeDef* I2Cx)
功能:
	返回通过 I2Cx 最近接收的数据
参数:
    I2Cx：x 可以是 1 或者 2，来选择 I2C 外设
返回值:
	接收到的字        
    

3.9 I2C_Send7bitAddress

/**
  * @brief  Transmits the address byte to select the slave device.
  * @param  I2Cx: where x can be 1 or 2 to select the I2C peripheral.
  * @param  Address: specifies the slave address which will be transmitted
  * @param  I2C_Direction: specifies whether the I2C device will be a
  *   Transmitter or a Receiver. This parameter can be one of the following values
  *     @arg I2C_Direction_Transmitter: Transmitter mode
  *     @arg I2C_Direction_Receiver: Receiver mode
  * @retval None.
  */
void I2C_Send7bitAddress(I2C_TypeDef* I2Cx, uint8_t Address, uint8_t I2C_Direction)
功能:
	向指定的从 I2C 设备传送地址字
参数:
    I2Cx：x 可以是 1 或者 2，来选择 I2C 外设
    Address: 待传输的从 I2C 地址
    I2C_Direction：设置指定的 I2C 设备工作为发射端还是接收端    
返回值:
	无     
    
    

3.10 I2C_CheckEvent

/**
  * @brief  Checks whether the last I2Cx Event is equal to the one passed
  *   as parameter.
  * @param  I2Cx: where x can be 1 or 2 to select the I2C peripheral.
  * @param  I2C_EVENT: specifies the event to be checked. 
  *   This parameter can be one of the following values:
  *     @arg I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED           : EV1
  *     @arg I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED              : EV1
  *     @arg I2C_EVENT_SLAVE_TRANSMITTER_SECONDADDRESS_MATCHED     : EV1
  *     @arg I2C_EVENT_SLAVE_RECEIVER_SECONDADDRESS_MATCHED        : EV1
  *     @arg I2C_EVENT_SLAVE_GENERALCALLADDRESS_MATCHED            : EV1
  *     @arg I2C_EVENT_SLAVE_BYTE_RECEIVED                         : EV2
  *     @arg (I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_DUALF)      : EV2
  *     @arg (I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_GENCALL)    : EV2
  *     @arg I2C_EVENT_SLAVE_BYTE_TRANSMITTED                      : EV3
  *     @arg (I2C_EVENT_SLAVE_BYTE_TRANSMITTED | I2C_FLAG_DUALF)   : EV3
  *     @arg (I2C_EVENT_SLAVE_BYTE_TRANSMITTED | I2C_FLAG_GENCALL) : EV3
  *     @arg I2C_EVENT_SLAVE_ACK_FAILURE                           : EV3_2
  *     @arg I2C_EVENT_SLAVE_STOP_DETECTED                         : EV4
  *     @arg I2C_EVENT_MASTER_MODE_SELECT                          : EV5
  *     @arg I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED            : EV6     
  *     @arg I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED               : EV6
  *     @arg I2C_EVENT_MASTER_BYTE_RECEIVED                        : EV7
  *     @arg I2C_EVENT_MASTER_BYTE_TRANSMITTING                    : EV8
  *     @arg I2C_EVENT_MASTER_BYTE_TRANSMITTED                     : EV8_2
  *     @arg I2C_EVENT_MASTER_MODE_ADDRESS10                       : EV9
  *     
  * @note: For detailed description of Events, please refer to section 
  *    I2C_Events in stm32f10x_i2c.h file.
  *    
  * @retval An ErrorStatus enumeration value:
  * - SUCCESS: Last event is equal to the I2C_EVENT
  * - ERROR: Last event is different from the I2C_EVENT
  */
ErrorStatus I2C_CheckEvent(I2C_TypeDef* I2Cx, uint32_t I2C_EVENT)
功能:
	检查指定的I2C的标志
参数:
    I2Cx：x 可以是 1 或者 2，来选择 I2C 外设
    I2C_Event：待检查的事件
返回值:
	ErrorStatus 枚举值：
	SUCCESS：最近一次 I2C 事件是 I2C_Event
    ERROR：最近一次 I2C 事件不是 I2C_Event

04. 硬件I2C读写MPU6050接线图

05. 硬件I2C读写MPU6050示例

MPU6050.h

#ifndef __MPU6050_H__

#define __MPU6050_H__


#include "mpu6050.h"
#include "stm32f10x.h" 


#define MPU6050_ADDRESS		    0xD0

#define	MPU6050_SMPLRT_DIV		0x19
#define	MPU6050_CONFIG			0x1A
#define	MPU6050_GYRO_CONFIG		0x1B
#define	MPU6050_ACCEL_CONFIG	0x1C

#define	MPU6050_ACCEL_XOUT_H	0x3B
#define	MPU6050_ACCEL_XOUT_L	0x3C
#define	MPU6050_ACCEL_YOUT_H	0x3D
#define	MPU6050_ACCEL_YOUT_L	0x3E
#define	MPU6050_ACCEL_ZOUT_H	0x3F
#define	MPU6050_ACCEL_ZOUT_L	0x40
#define	MPU6050_TEMP_OUT_H		0x41
#define	MPU6050_TEMP_OUT_L		0x42
#define	MPU6050_GYRO_XOUT_H		0x43
#define	MPU6050_GYRO_XOUT_L		0x44
#define	MPU6050_GYRO_YOUT_H		0x45
#define	MPU6050_GYRO_YOUT_L		0x46
#define	MPU6050_GYRO_ZOUT_H		0x47
#define	MPU6050_GYRO_ZOUT_L		0x48

#define	MPU6050_PWR_MGMT_1		0x6B
#define	MPU6050_PWR_MGMT_2		0x6C
#define	MPU6050_WHO_AM_I		0x75




void MPU6050_WriteReg(uint8_t regAddr, uint8_t data);
uint8_t MPU6050_ReadReg(uint8_t regAddr);
void MPU6050_init(void);
uint8_t MPU6050_getId(void);
void MPU6050_getData(int16_t *AccX, int16_t *AccY, int16_t *AccZ, 
						int16_t *GyroX, int16_t *GyroY, int16_t *GyroZ);


#endif /*__MPU6050_H__*/

MPU6050.c

#include "mpu6050.h"

void MPU6050_WaitEvent(I2C_TypeDef* I2Cx, uint32_t I2C_EVENT)
{
	uint32_t timeout;
	timeout = 100000;
	
	while(I2C_CheckEvent(I2Cx, I2C_EVENT) != SUCCESS)
	{
		timeout--;
		if (0 == timeout)
		{
			break;
		}
	}
}



void MPU6050_WriteReg(uint8_t regAddr, uint8_t data)
{
	//发送起始条件
	I2C_GenerateSTART(I2C2, ENABLE);
	MPU6050_WaitEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT);
	
	//发送7位地址
	I2C_Send7bitAddress(I2C2, MPU6050_ADDRESS, I2C_Direction_Transmitter);
	MPU6050_WaitEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED);
	
	//发送寄存器地址
	I2C_SendData(I2C2, regAddr);
		MPU6050_WaitEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTING);
	
	//发送数据
	I2C_SendData(I2C2, data);
		MPU6050_WaitEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED);
	
	//发送停止位
	I2C_GenerateSTOP(I2C2, ENABLE);
	
}

uint8_t MPU6050_ReadReg(uint8_t regAddr)
{
	uint8_t data = 0;
	
	//发送起始条件
	I2C_GenerateSTART(I2C2, ENABLE);
		MPU6050_WaitEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT);
	
	//发送7位地址
	I2C_Send7bitAddress(I2C2, MPU6050_ADDRESS, I2C_Direction_Transmitter);
	MPU6050_WaitEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED);
	
	//发送寄存器地址
	I2C_SendData(I2C2, regAddr);
		MPU6050_WaitEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED);
	
	//发送起始条件
	I2C_GenerateSTART(I2C2, ENABLE);
	MPU6050_WaitEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT);
	
	//发送7位地址
	I2C_Send7bitAddress(I2C2, MPU6050_ADDRESS, I2C_Direction_Receiver);
	MPU6050_WaitEvent(I2C2, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED);
	
	I2C_AcknowledgeConfig(I2C2, DISABLE);
	I2C_GenerateSTOP(I2C2, ENABLE);
	
		MPU6050_WaitEvent(I2C2, I2C_EVENT_MASTER_BYTE_RECEIVED);
	data = I2C_ReceiveData(I2C2);
	
	I2C_AcknowledgeConfig(I2C2, ENABLE);
	
	
	return data;
}


void MPU6050_init(void)
{
	GPIO_InitTypeDef GPIO_InitStruct;
	I2C_InitTypeDef I2C_InitStruct;
	
	//I2C初始化
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);
	
		
	//PB10 PB11
	GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_OD;
	GPIO_InitStruct.GPIO_Pin = GPIO_Pin_11 | GPIO_Pin_10;
	GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOB, &GPIO_InitStruct);
	
	I2C_InitStruct.I2C_Mode = I2C_Mode_I2C;
	I2C_InitStruct.I2C_ClockSpeed = 50000;
	I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2;
	I2C_InitStruct.I2C_Ack = I2C_Ack_Enable;
	I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
	I2C_InitStruct.I2C_OwnAddress1 = 0x00;
	I2C_Init(I2C2, &I2C_InitStruct);
	
	//使能I2C
	I2C_Cmd(I2C2, ENABLE);
	
	
	MPU6050_WriteReg(MPU6050_PWR_MGMT_1, 0x01);
	MPU6050_WriteReg(MPU6050_PWR_MGMT_2, 0x00);
	MPU6050_WriteReg(MPU6050_SMPLRT_DIV, 0x09);
	MPU6050_WriteReg(MPU6050_CONFIG, 0x06);
	MPU6050_WriteReg(MPU6050_GYRO_CONFIG, 0x18);
	MPU6050_WriteReg(MPU6050_ACCEL_CONFIG, 0x18);
}

uint8_t MPU6050_getId(void)
{
	return MPU6050_ReadReg(MPU6050_WHO_AM_I);
}

void MPU6050_getData(int16_t *AccX, int16_t *AccY, int16_t *AccZ, 
						int16_t *GyroX, int16_t *GyroY, int16_t *GyroZ)
{
	uint8_t DataH, DataL;
	
	DataH = MPU6050_ReadReg(MPU6050_ACCEL_XOUT_H);
	DataL = MPU6050_ReadReg(MPU6050_ACCEL_XOUT_L);
	*AccX = (DataH << 8) | DataL;
	
	DataH = MPU6050_ReadReg(MPU6050_ACCEL_YOUT_H);
	DataL = MPU6050_ReadReg(MPU6050_ACCEL_YOUT_L);
	*AccY = (DataH << 8) | DataL;
	
	DataH = MPU6050_ReadReg(MPU6050_ACCEL_ZOUT_H);
	DataL = MPU6050_ReadReg(MPU6050_ACCEL_ZOUT_L);
	*AccZ = (DataH << 8) | DataL;
	
	DataH = MPU6050_ReadReg(MPU6050_GYRO_XOUT_H);
	DataL = MPU6050_ReadReg(MPU6050_GYRO_XOUT_L);
	*GyroX = (DataH << 8) | DataL;
	
	DataH = MPU6050_ReadReg(MPU6050_GYRO_YOUT_H);
	DataL = MPU6050_ReadReg(MPU6050_GYRO_YOUT_L);
	*GyroY = (DataH << 8) | DataL;
	
	DataH = MPU6050_ReadReg(MPU6050_GYRO_ZOUT_H);
	DataL = MPU6050_ReadReg(MPU6050_GYRO_ZOUT_L);
	*GyroZ = (DataH << 8) | DataL;
}

main.c

#include "stm32f10x.h"

#include "delay.h"
#include "oled.h"
#include "mpu6050.h"


 int main(void)
 {	 
	 uint8_t data = 0;
	 int16_t AX, AY, AZ, GX, GY, GZ;

	 //初始化
	 OLED_Init();
	 MPU6050_init();
	 
	 data = MPU6050_getId();
	 OLED_ShowString(1, 1, "ID: ");
	 OLED_ShowHexNum(1, 5, data, 3);
	 
 
	 while(1)
	 {
		
		MPU6050_getData(&AX, &AY, &AZ, &GX, &GY, &GZ);
		OLED_ShowSignedNum(2, 1, AX, 5);
		OLED_ShowSignedNum(3, 1, AY, 5);
		OLED_ShowSignedNum(4, 1, AZ, 5);
		OLED_ShowSignedNum(2, 8, GX, 5);
		OLED_ShowSignedNum(3, 8, GY, 5);
		OLED_ShowSignedNum(4, 8, GZ, 5);
		
		 delay_ms(100);
		 
	 }
	 
	 return 0;
 }


 

06. 程序下载

29-硬件I2C读写MPU6050.rar

07. 附录

参考: 【STM32】江科大STM32学习笔记汇总