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mình đang đọc dữ liệu từ la bàn số CMPS10 dùng mạch stm32f4 bằng mode I2C mà làm mãi không đc... mong ace giúp đỡ mình sớm... tks pà còn nha.
PHP Code:
#include "stm32f4_discovery.h"
#define MAG_ADDRESS 0xC0 // the slave address (example)
uint8_t data;
uint8_t received_data[2];
void init_I2C1(void){
GPIO_InitTypeDef GPIO_InitStruct;
I2C_InitTypeDef I2C_InitStruct;
// enable APB1 peripheral clock for I2C1
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
// enable clock for SCL and SDA pins
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
/* setup SCL and SDA pins
* You can connect I2C1 to two different
* pairs of pins:
* 1. SCL on PB6 and SDA on PB7
* 2. SCL on PB8 and SDA on PB9
*/
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_9; // we are going to use PB6 and PB7
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF; // set pins to alternate function
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; // set GPIO speed
GPIO_InitStruct.GPIO_OType = GPIO_OType_OD; // set output to open drain --> the line has to be only pulled low, not driven high
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP; // enable pull up resistors
GPIO_Init(GPIOB, &GPIO_InitStruct); // init GPIOB
// Connect I2C1 pins to AF
GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_I2C1); // SCL
GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_I2C1); // SDA
// configure I2C1
I2C_InitStruct.I2C_ClockSpeed = 100000; // 100kHz
I2C_InitStruct.I2C_Mode = I2C_Mode_I2C; // I2C mode
I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2; // 50% duty cycle --> standard
I2C_InitStruct.I2C_OwnAddress1 = 0x00; // own address, not relevant in master mode
I2C_InitStruct.I2C_Ack = I2C_Ack_Disable; // disable acknowledge when reading (can be changed later on)
I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit; // set address length to 7 bit addresses
I2C_Init(I2C1, &I2C_InitStruct); // init I2C1
// enable I2C1
I2C_Cmd(I2C1, ENABLE);
}
/* This function issues a start condition and
* transmits the slave address + R/W bit
*
* Parameters:
* I2Cx --> the I2C peripheral e.g. I2C1
* address --> the 7 bit slave address
* direction --> the tranmission direction can be:
* I2C_Direction_Tranmitter for Master transmitter mode
* I2C_Direction_Receiver for Master receiver
*/
void I2C_start(I2C_TypeDef* I2Cx, uint8_t address, uint8_t direction){
// wait until I2C1 is not busy anymore
while(I2C_GetFlagStatus(I2Cx, I2C_FLAG_BUSY));
// Send I2C1 START condition
I2C_GenerateSTART(I2Cx, ENABLE);
// wait for I2C1 EV5 --> Slave has acknowledged start condition
while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_MODE_SELECT));
// Send slave Address for write
I2C_Send7bitAddress(I2Cx, address, direction);
/* wait for I2C1 EV6, check if
* either Slave has acknowledged Master transmitter or
* Master receiver mode, depending on the transmission
* direction
*/
if(direction == I2C_Direction_Transmitter){
while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
}
else if(direction == I2C_Direction_Receiver){
while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));
}
}
/* This function transmits one byte to the slave device
* Parameters:
* I2Cx --> the I2C peripheral e.g. I2C1
* data --> the data byte to be transmitted
*/
void I2C_write(I2C_TypeDef* I2Cx, uint8_t data){
I2C_SendData(I2Cx, data);
// wait for I2C1 EV8_2 --> byte has been transmitted
while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
}
/* This function reads one byte from the slave device
* and acknowledges the byte (requests another byte)
*/
uint8_t I2C_read_ack(I2C_TypeDef* I2Cx){
// enable acknowledge of recieved data
I2C_AcknowledgeConfig(I2Cx, ENABLE);
// wait until one byte has been received
while( !I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_RECEIVED) );
// read data from I2C data register and return data byte
data = I2C_ReceiveData(I2Cx);
return data;
}
/* This function reads one byte from the slave device
* and doesn't acknowledge the recieved data
*/
uint8_t I2C_read_nack(I2C_TypeDef* I2Cx){
// disabe acknowledge of received data
I2C_AcknowledgeConfig(I2Cx, DISABLE);
// wait until one byte has been received
while( !I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_RECEIVED) );
// read data from I2C data register and return data byte
data = I2C_ReceiveData(I2Cx);
return data;
}
/* This funtion issues a stop condition and therefore
* releases the bus
*/
void I2C_stop(I2C_TypeDef* I2Cx){
// Send I2C1 STOP Condition
I2C_GenerateSTOP(I2Cx, ENABLE);
}
uint8_t out[] = {0,0,0,0,0,0,0};
int main(void){
init_I2C1(); // initialize I2C peripheral
while (1)
{
I2C1->DR = 0;
I2C_GenerateSTART(I2C1, ENABLE);
I2C_Send7bitAddress(I2C1,MAG_ADDRESS,I2C_Direction_Transmitter);
I2C_SendData(I2C1,5);
I2C_SendData(I2C1,3);
I2C_GenerateSTART(I2C1, DISABLE);
I2C_GenerateSTOP(I2C1, ENABLE);
I2C_GenerateSTOP(I2C1, DISABLE);
I2C_GenerateSTART(I2C1, ENABLE);
I2C_Send7bitAddress(I2C1,MAG_ADDRESS,I2C_Direction_Transmitter);
I2C_SendData(I2C1,0x00);
I2C_SendData(I2C1,(1<<3)|(1<<4));
I2C_GenerateSTART(I2C1, DISABLE);
I2C_GenerateSTOP(I2C1, ENABLE);
I2C_GenerateSTOP(I2C1, DISABLE);
I2C_GenerateSTART(I2C1, ENABLE);
I2C_Send7bitAddress(I2C1,MAG_ADDRESS,I2C_Direction_Transmitter);
I2C_SendData(I2C1,5);
I2C_Send7bitAddress(I2C1,MAG_ADDRESS,I2C_Direction_Receiver);
out[0] = I2C_ReceiveData(I2C1);
out[1] = I2C_ReceiveData(I2C1);
out[2] = I2C_ReceiveData(I2C1);
out[3] = I2C_ReceiveData(I2C1);
out[4] = I2C_ReceiveData(I2C1);
out[5] = I2C_ReceiveData(I2C1);
out[6] = I2C_ReceiveData(I2C1);
I2C_GenerateSTART(I2C1, DISABLE);
I2C_GenerateSTOP(I2C1, ENABLE);
I2C_GenerateSTOP(I2C1, DISABLE);
}
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
while (1)
{}
}
#endif
/**
* @}
*/
/**
* @}
*/
/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/
... không có lấy gì mà giúp !
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