陀螺仪学习资料

L3GD20陀螺仪学习1.初始化L3GD20端口配置。

将端口配置为SPI通信接口。

单片机端口初始化包括I/O端口，I/O端口spi系统时钟。

以STM32F303为例配置端口如下：static void L3GD20_LowLevel_Init(void){GPIO_InitTypeDef GPIO_InitStructure;SPI_InitTypeDef SPI_InitStructure;/* Enable the SPI periph */RCC_APB2PeriphClockCmd(L3GD20_SPI_CLK, ENABLE);/* Enable SCK, MOSI and MISO GPIO clocks */RCC_AHBPeriphClockCmd(L3GD20_SPI_SCK_GPIO_CLK | L3GD20_SPI_MISO_GPIO_CLK | L3GD20_SPI_MOSI_GPIO_CLK, ENABLE);/* Enable CS GPIO clock */RCC_AHBPeriphClockCmd(L3GD20_SPI_CS_GPIO_CLK, ENABLE);/* Enable INT1 GPIO clock */RCC_AHBPeriphClockCmd(L3GD20_SPI_INT1_GPIO_CLK, ENABLE);/* Enable INT2 GPIO clock */RCC_AHBPeriphClockCmd(L3GD20_SPI_INT2_GPIO_CLK, ENABLE);GPIO_PinAFConfig(L3GD20_SPI_SCK_GPIO_PORT, L3GD20_SPI_SCK_SOURCE, L3GD20_SPI_SCK_AF);GPIO_PinAFConfig(L3GD20_SPI_MISO_GPIO_PORT, L3GD20_SPI_MISO_SOURCE, L3GD20_SPI_MISO_AF);GPIO_PinAFConfig(L3GD20_SPI_MOSI_GPIO_PORT, L3GD20_SPI_MOSI_SOURCE, L3GD20_SPI_MOSI_AF);GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;//GPIO_PuPd_DOWN;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;/* SPI SCK pin configuration */GPIO_InitStructure.GPIO_Pin = L3GD20_SPI_SCK_PIN;GPIO_Init(L3GD20_SPI_SCK_GPIO_PORT, &GPIO_InitStructure);/* SPI MOSI pin configuration */GPIO_InitStructure.GPIO_Pin = L3GD20_SPI_MOSI_PIN;GPIO_Init(L3GD20_SPI_MOSI_GPIO_PORT, &GPIO_InitStructure);/* SPI MISO pin configuration */GPIO_InitStructure.GPIO_Pin = L3GD20_SPI_MISO_PIN;GPIO_Init(L3GD20_SPI_MISO_GPIO_PORT, &GPIO_InitStructure);/* SPI configuration -------------------------------------------------------*/SPI_I2S_DeInit(L3GD20_SPI);SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex; 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_8; SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;SPI_InitStructure.SPI_CRCPolynomial = 7;SPI_InitStructure.SPI_Mode = SPI_Mode_Master;SPI_Init(L3GD20_SPI, &SPI_InitStructure);/* Configure the RX FIFO Threshold */SPI_RxFIFOThresholdConfig(L3GD20_SPI, SPI_RxFIFOThreshold_QF); /* Enable SPI1 */SPI_Cmd(L3GD20_SPI, ENABLE);/* Configure GPIO PIN for Lis Chip select */GPIO_InitStructure.GPIO_Pin = L3GD20_SPI_CS_PIN;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(L3GD20_SPI_CS_GPIO_PORT, &GPIO_InitStructure);/* Deselect : Chip Select high */GPIO_SetBits(L3GD20_SPI_CS_GPIO_PORT, L3GD20_SPI_CS_PIN); /* Configure GPIO PINs to detect Interrupts */GPIO_InitStructure.GPIO_Pin = L3GD20_SPI_INT1_PIN;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;GPIO_Init(L3GD20_SPI_INT1_GPIO_PORT, &GPIO_InitStructure);GPIO_InitStructure.GPIO_Pin = L3GD20_SPI_INT2_PIN;GPIO_Init(L3GD20_SPI_INT2_GPIO_PORT, &GPIO_InitStructure);}2.陀螺仪初始化配置配置陀螺仪芯片功能和芯片初始化设置对应寄存器配置及功能参考LG3D20数据手册代码示例如下：void L3GD20_Init(L3GD20_InitTypeDef *L3GD20_InitStruct){uint8_t ctrl1 = 0x00, ctrl4 = 0x00;/* Configure the low level interface ---------------------------------------*/L3GD20_LowLevel_Init();/* Configure MEMS: data rate, power mode, full scale and axes */L3GD20_InitStructure.Power_Mode = L3GD20_MODE_ACTIVE; //0x08 L3GD20_InitStructure.Output_DataRate = L3GD20_OUTPUT_DATARA TE_1; //0x00L3GD20_InitStructure.Axes_Enable = L3GD20_AXES_ENABLE; //0x07L3GD20_InitStructure.Band_Width = L3GD20_BANDWIDTH_4; //0x30L3GD20_InitStructure.BlockData_Update = L3GD20_BlockDataUpdate_Continous; //0x00 L3GD20_InitStructure.Endianness = L3GD20_BLE_LSB; //0x00L3GD20_InitStructure.Full_Scale = L3GD20_FULLSCALE_500; //0x10ctrl1 |= (uint8_t) (L3GD20_InitStruct->Power_Mode | L3GD20_InitStruct->Output_DataRate | \L3GD20_InitStruct->Axes_Enable | L3GD20_InitStruct->Band_Width);ctrl4 |= (uint8_t) (L3GD20_InitStruct->BlockData_Update | L3GD20_InitStruct->Endianness | \L3GD20_InitStruct->Full_Scale);/* Write value to MEMS CTRL_REG1 regsister addres 0x20 Control register 1 write 0x3f */L3GD20_Write(&ctrl1, L3GD20_CTRL_REG1_ADDR, 1);/* Write value to MEMS CTRL_REG4 regsister addres 0x23 Control register 1 write 0x10 */L3GD20_Write(&ctrl4, L3GD20_CTRL_REG4_ADDR, 1);}void L3GD20_FilterConfig(L3GD20_FilterConfigTypeDef *L3GD20_FilterStruct){uint8_t tmpreg;/* Read CTRL_REG2 register */L3GD20_Read(&tmpreg, L3GD20_CTRL_REG2_ADDR, 1);tmpreg &= 0xC0;L3GD20_FilterStructure.HighPassFilter_Mode_Selection=L3GD20_HPM_NORMAL_MODE_RES; //0x00L3GD20_FilterStructure.HighPassFilter_CutOff_Frequency = L3GD20_HPFCF_0;//0x00/* Configure MEMS: mode and cutoff frquency */tmpreg |= (uint8_t) (L3GD20_FilterStruct->HighPassFilter_Mode_Selection |\L3GD20_FilterStruct->HighPassFilter_CutOff_Frequency);/* Write value to MEMS CTRL_REG2 regsister addres 0x21 Control register write 0xc0*/L3GD20_Write(&tmpreg, L3GD20_CTRL_REG2_ADDR, 1);}void L3GD20_FilterCmd(uint8_t HighPassFilterState){uint8_t tmpreg;/* Read CTRL_REG5 register */L3GD20_Read(&tmpreg, L3GD20_CTRL_REG5_ADDR, 1);tmpreg &= 0xEF;tmpreg |= HighPassFilterState; //0x10/* Write value to MEMS CTRL_REG5 regsister 0x24 Control register write 0xff*/L3GD20_Write(&tmpreg, L3GD20_CTRL_REG5_ADDR, 1);}3.L3GD20配置SPI数据读、写寄存器函数读取函数L3GD20_Read(uint8_t* pBuffer, uint8_t ReadAddr, uint16_t NumByteToRead) void L3GD20_Read(uint8_t* pBuffer, uint8_t ReadAddr, uint16_t NumByteToRead){if(NumByteToRead > 0x01){ReadAddr |= (uint8_t)(READWRITE_CMD | MULTIPLEBYTE_CMD);}else{ReadAddr |= (uint8_t)READWRITE_CMD;}/* Set chip select Low at the start of the transmission */L3GD20_CS_LOW();/* Send the Address of the indexed register */L3GD20_SendByte(ReadAddr);/* Receive the data that will be read from the device (MSB First) */while(NumByteToRead > 0x00){/* Send dummy byte (0x00) to generate the SPI clock to L3GD20 (Slave device) */*pBuffer = L3GD20_SendByte(DUMMY_BYTE);NumByteToRead--;pBuffer++;}/* Set chip select High at the end of the transmission */L3GD20_CS_HIGH();}写L3GD20寄存器函数L3GD20_Write(uint8_t* pBuffer, uint8_t WriteAddr, uint16_t NumByteToWrite)void L3GD20_Write(uint8_t* pBuffer, uint8_t WriteAddr, uint16_t NumByteToWrite){/* Configure the MS bit:- When 0, the address will remain unchanged in multiple read/write commands.- When 1, the address will be auto incremented in multiple read/write commands.if(NumByteToWrite > 0x01){WriteAddr |= (uint8_t)MULTIPLEBYTE_CMD;}/* Set chip select Low at the start of the transmission */L3GD20_CS_LOW();/* Send the Address of the indexed register */L3GD20_SendByte(WriteAddr);/* Send the data that will be written into the device (MSB First) */while(NumByteToWrite >= 0x01){L3GD20_SendByte(*pBuffer);NumByteToWrite--;pBuffer++;}/* Set chip select High at the end of the transmission */L3GD20_CS_HIGH();}4.封装读取陀螺仪3轴数据函数将读取出来的数据进行处理计算Demo_GyroReadAngRate (float* pfData)void Demo_GyroReadAngRate (float* pfData){uint8_t tmpbuffer[6] ={0};int16_t RawData[3] = {0};uint8_t tmpreg = 0;float sensitivity = 0;int i =0;L3GD20_Read(&tmpreg,L3GD20_CTRL_REG4_ADDR,1);L3GD20_Read(tmpbuffer,L3GD20_OUT_X_L_ADDR,6);/* check in the control register 4 the data alignment (Big Endian or Little Endian)*/ /* 将10位数据进行叠加并选择大、小端模式处理*/if(!(tmpreg & 0x40)){for(i=0; i<3; i++){RawData[i]=(int16_t)(((uint16_t)tmpbuffer[2*i+1] << 8) + tmpbuffer[2*i]);}}else{for(i=0; i<3; i++)RawData[i]=(int16_t)(((uint16_t)tmpbuffer[2*i] << 8) + tmpbuffer[2*i+1]);}}/* Switch the sensitivity value set in the CRTL4 */switch(tmpreg & 0x30){case 0x00:sensitivity=L3G_Sensitivity_250dps;//L3G_Sensitivity_500dps=360/pibreak;case 0x10:sensitivity=L3G_Sensitivity_500dps; //L3G_Sensitivity_500dps=180/pi=57.1429 break;case 0x20:sensitivity=L3G_Sensitivity_2000dps;//L3G_Sensitivity_500dps=1/4*180/pibreak;}/* divide by sensitivity */for(i=0; i<3; i++){pfData[i]=(float)RawData[i]/sensitivity; //读出数据除以量程}}后续就是自己的算法处理机判断。