The MPU 6050 is actually an I2C device, there are many registers (but only a few of us), we use the read and write registers to operate this chip. Therefore, the primary problem is the I2C communication of STM32 and MPU 6050.
1. Configure STM32 (with I2C1: PB6 - SCL; PB7 - SDA)
1) Clock RCC
RCC_APB2PeriPhClockCMD (RCC_APB2PeriPh_GPIOB, Enable);
Rcc_apb1periphclockcmd (RCC_APB1PeriPH_i2c1, Enable);
2) GPIO configuration
GPIO_INITSTRUCTURE.GPIO_PIN = GPIO_PIN_6 | GPIO_PIN_7;
GPIO_INITSTRUCTURE.GPIO_SPEED = GPIO_SPEED_50MHz;
GPIO_INITSTRUCTURE.GPIO_MODE = GPIO_MODE_AF_OD; // Two pins plus 4.7k pull-up resistor
GPIO_INIT (GPIOB, & GPIO_INITSTRUCTURE);
3) I2C configuration
Void I2C_Configuration (Void)
{
I2C_INITTYPEDEF I2C_INITSTRUCTURE
I2C_INITSTRUCTURE.I2C_MODE = I2C_MODE_I2C;
I2C_INITSTRUCTURE.I2C_DUTYCYCLE = I2C_Dutycycle_2;
I2C_INITSTRUCTURE.I2C_OWNADDRESS1 = 0xc0; // STM32's own address, not the same as the slave
I2C_INITSTRUCTURE.I2C_ACK = I2C_ACK_ENABLE;
I2C_INITSTRUCTURE.I2C_ACKNOWEDGEDADDRESS = I2C_Acknowledged ADDRESS_7BIT;
I2C_INITSTRUCTURE.I2C_ClockSpeed = 100000;
I2C_INIT (I2C1, & I2C_INITSTRUCTURE);
I2C_CMD (i2c1, enable);
}
At this point, STM32 is configured, it is not so difficult.
2, initialization MPU6050
Void MPU6050_Initialize () // Initialization process, actually writing 5 registers
{
MPU6050_I2C_BYTEWRITE (0xD0, 0x00, MPU6050_RA_PWR_MGMT_1); // reg107, awakening, 8M internal clock source
MPU6050_I2C_BYTEWRITE (0xD0, 0x07, MPU6050_RA_SMPLRT_DIV); // Using frequency 1000
MPU6050_I2C_BYTEWRITE (0xD0, 0x06, MPU6050_RA_CONFIG);
MPU6050_I2C_BYTEWRITE (0xD0, 0x01, MPU6050_RA_ACCEL_CONFIG); // Acceleration Rule 2G
MPU6050_I2C_BYTEWRITE (0xD0, 0x18, MPU6050_RA_GYRO_CONFIG); // angular velocity range 2000 degrees / s
}
Note: 0xD0 represents the address of the MPU 6050. We know that I2C is from the device (here, it means that the MPU 6050) has 8-bit addresses, the top 7 bits are determined by the WHO AM I, and the 8th bit is determined by the level of AD0. The WHO AM I default is 0x68h (1101000B), the AD0 is lowered, so the I2C address of the MPU 6050 is 0xD0H (11010000B).
3, I2C core program (read / write)
1) Write register
One write operation is divided into several steps: send start signal - "start success? (Possible to describe it) - "Send the MPU 6050 address, the status (write) -" write address success? - "Send an MPU 6050 inside some to write register address -" Send success? - "Send the content to be written -" Send success? - "Send end signal
Summary: First write the MPU6050 address, write the register address, last write content, and each time you have to verify (should be related to the response signal). This is like sending a courier, first writting the county address, then write the street address, and finally written the number.
Look at the procedures below will be more likely to understand.
Void MPU6050_I2C_ByTewrite (U8 Slaveaddr, U8 PBuffer, U8 WriteAddr)
{
/ * Send start condition * /
I2C_GenerateStart (I2C1, Enable); // Send start signal
/ * TEST ON EV5 and CLEAR IT * /
While (! I2c_checkevent (i2c1, i2c_event_master_mode_select);
/ * Send MPU6050 Address for Write * /
I2C_send7bitaddress (i2c1, slaveaddr, i2c_direction_transmitter); // Send MPU6050 address, status (write)
/ * TEST ON EV6 and CLEAR IT * /
While (! I2c_checkevent (i2c1, i2c_event_master_transmitter_mode_selected);
/ * Send the MPU6050's Internal Address to Write to * /
I2C_senddata (I2C1, WriteAddr); / / Send an internal to-write register address within the MPU 6050
/ * TEST ON EV8 and CLEAR IT * /
While (! I2c_checkevent (i2c1, i2c_event_master_byte_transmitted);
/ * Send the byte to be written * /
I2C_senddata (I2C1, PBuffer); // Send content to be written
/ * TEST ON EV8 and CLEAR IT * /
While (! I2c_checkevent (i2c1, i2c_event_master_byte_transmitted);
/ * Send Stop Condition * /
I2C_GenerateStop (i2c1, enable); // Send end signal
}, Read the full text, the technical area
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