Connection of an accelerometer MMA8452Q to the correspondent STM32 peripheral

[ilvuciis]

Posted on November 17, 2016 at 21:02

I have some issues with the STM32 code for Connection of an accelerometer MMA8452Q to the correspondent STM32 peripheral I2C communication.

What is missing?#include ''stm32f10x.h''#include ''lcd.h''#include ''stdio.h''volatile u8 X, Y, Z;

void usart_config(){

void RCC_Config_HSE_PLL_Max(){ RCC_DeInit(); RCC_HSEConfig(RCC_HSE_ON); ErrorStatus HSEStartUpStatus; HSEStartUpStatus = RCC_WaitForHSEStartUp(); if(HSEStartUpStatus == SUCCESS) { FLASH_SetLatency(FLASH_Latency_2); FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable); RCC_HCLKConfig(RCC_SYSCLK_Div1); RCC_PCLK1Config(RCC_HCLK_Div1); RCC_PCLK2Config(RCC_HCLK_Div1); RCC_PLLConfig(RCC_PLLSource_HSE_Div2, RCC_PLLMul_12); RCC_PLLCmd(ENABLE); while( RCC_GetFlagStatus( RCC_FLAG_PLLRDY ) == RESET ); RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); while(RCC_GetSYSCLKSource() != 0x08); } else while(1); } //configuration of the LED RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); GPIO_InitTypeDef GPIO_InitStructure; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_Init(GPIOA, &GPIO_InitStructure); //USART configuration RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE); USART_InitTypeDef USART_InitStructure; //default baudrate - 9600 USART_InitStructure.USART_BaudRate = 9600; //databits - 8 USART_InitStructure.USART_WordLength = USART_WordLength_8b; //stopbits - 1 USART_InitStructure.USART_StopBits = USART_StopBits_1; //odd parity USART_InitStructure.USART_Parity = USART_Parity_Odd; //no hardware flowcontrol USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; //both receiving and transmitting mode USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx; USART_Init(USART2, &USART_InitStructure); USART_Cmd(USART2, ENABLE); //USART interruption configuration NVIC_InitTypeDef NVIC_InitStructure; NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1); NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);}void i2cconfig(){    GPIO_InitTypeDef  GPIO_InitStructure;    I2C_InitTypeDef  I2C_InitStructure;    /*enable I2C*/    I2C_Cmd(I2C2,ENABLE);    /* I2C2 clock enable */    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);    // I2C2 SDA and SCL configuration, SCL is pin11 and SDA is pin 12 for I2C2    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;    GPIO_Init(GPIOB, &GPIO_InitStructure);   I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;    I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;    I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;    I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;    I2C_InitStructure.I2C_ClockSpeed = 500000;    I2C_InitStructure.I2C_OwnAddress1 = 0;    I2C_Init(I2C2, &I2C_InitStructure);    I2C_Cmd(I2C2, ENABLE);}void I2C_receiver_one(){I2C_GenerateSTART(I2C2, ENABLE); //Start condition to start communicating with the slavewhile(!(I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT)));I2C_Send7bitAddress(I2C2, 0x1D, I2C_Direction_Transmitter); while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));I2C_SendData(I2C2,0x2A);while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));I2C_GenerateSTART(I2C2, ENABLE); //Start condition to start communicating with the slavewhile(!(I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT)));I2C_Send7bitAddress(I2C2, 0x1D, I2C_Direction_Receiver);    // Test Receive mode Flag    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_RECEIVED));  X = I2C_ReceiveData(I2C2);  I2C_AcknowledgeConfig(I2C2, DISABLE);I2C_GenerateSTOP(I2C2, ENABLE);while(I2C_GetFlagStatus(I2C2, I2C_FLAG_STOPF)); // stop bit flag}int main(void) { RCC_Config_HSE_PLL_Max(); lcd_init (); i2cconfig(); usart_config(); I2C_receiver_one(); while(1)    {    } }And the handler:extern X;extern Y;extern Z;void USART2_IRQHandler(void){ //variables for the received data and for the switch status volatile uint8_t RxData; //if it is receiving if(USART_GetITStatus(USART2, USART_IT_RXNE)== SET) { // while it is still receiving data do.... while( USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == RESET ); //attribution of the received data to the rxdata variable     RxData = USART_ReceiveData(USART2);   if (RxData=='a')   {   GPIO_SetBits(GPIOA,GPIO_Pin_2);   //u8 X, Y, Z;   char buffer1 [10];   char buffer2 [10];   char buffer3 [10];   sprintf(buffer1,''X = %d'', X);   sprintf(buffer2,''Y = %d'', Y);   sprintf(buffer3,''Z = %d'', Z); lcd_draw_string(5,20,buffer1,1000,1);   lcd_draw_string(5,60,buffer2,1000,1);     lcd_draw_string(5,100,buffer3,1000,1);     while( USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == RESET );     RxData = USART_ReceiveData(USART2);     USART_ClearFlag(USART2,USART_FLAG_RXNE);     } USART_ClearFlag(USART2,USART_FLAG_RXNE); USART_ClearITPendingBit(USART2, USART_IT_RXNE); }}

[Walid FTITI_O]

Posted on November 29, 2016 at 12:03

Hi aleksandrova.ilva, 

You would refer to the demonstration example in 

http://www.st.com/en/embedded-software/stm32cubef4.html

at this path:STM32Cube_FW_F4_V1.14.0\Projects\STM32F4-Discovery\DemonstrationsThis demonstartion example interface the MEMS sensor (LIS302DL for revB or LIS3DSCH for revC), when you move the board you observe the four Leds blinking according to the motion direction.You may then interface the MMA8452Q the same way as LIS302DL.-Hannibal-