i2c.c
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#include "i2c.h"
#include "libwismart.h"
void I2C_init(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
I2C_InitTypeDef I2C_InitStruct;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
/*
* 1. SCL on PB6 or PB8
* 2. SDA on PB7 or PB9
*/
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStruct); // init GPIOB
/* WARNING
*
* Check consistency with above configuration
*
* --Imanol
*/
// configure I2C1
I2C_InitStruct.I2C_ClockSpeed = 100000; // 100kHz - STANDARD MODE
I2C_InitStruct.I2C_Mode = I2C_Mode_I2C;
I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2;
I2C_InitStruct.I2C_OwnAddress1 = 0x00;
I2C_InitStruct.I2C_Ack = I2C_Ack_Enable;
I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_Init(I2C1, &I2C_InitStruct);
I2C_Cmd(I2C1, ENABLE);
}
void I2C_start(I2C_TypeDef* I2Cx, uint8_t address, uint8_t direction)
{
while(I2C_GetFlagStatus(I2Cx, I2C_FLAG_BUSY))
{
// wait until I2C1 is not busy any more
}
I2C_GenerateSTART(I2Cx, ENABLE);
while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_MODE_SELECT))
{
// wait for I2C1 EV5 --> Slave has acknowledged start condition
}
I2C_Send7bitAddress(I2Cx, address, direction);
if(direction == I2C_Direction_Transmitter)
{
while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED))
{
// wait for I2Cx EV6, check if Slave has acknowledged Master transmitter mode
}
}
else if(direction == I2C_Direction_Receiver)
{
while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED))
{
// wait for I2Cx EV6, check if Slave has acknowledged Master receiver mode
}
}
}
void I2C_write(I2C_TypeDef* I2Cx, uint8_t data)
{
/* WARNING
*
* OJITO QUE ESTÁ ESPERANDO EL EV8 Y NO EL EV8_2
*
* --Imanol
*/
while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTING))
{
// wait for I2C1 EV8 --> last byte is still being transmitted (last byte in SR, buffer empty), next byte can already be written
}
I2C_SendData(I2Cx, data);
}
uint8_t I2C_read_ack(I2C_TypeDef* I2Cx)
{
I2C_AcknowledgeConfig(I2Cx, ENABLE);
while( !I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_RECEIVED))
{
// wait until one byte has been received
}
return I2C_ReceiveData(I2Cx);
}
uint8_t I2C_read_nack(I2C_TypeDef* I2Cx)
{
I2C_AcknowledgeConfig(I2Cx, DISABLE);
I2C_GenerateSTOP(I2Cx, ENABLE);
while( !I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_RECEIVED))
{
// wait until one byte has been received
}
return I2C_ReceiveData(I2Cx);
}
void I2C_stop(I2C_TypeDef* I2Cx)
{
I2C_GenerateSTOP(I2Cx, ENABLE);
while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTED))
{
// wait for I2C1 EV8_2 --> byte has been transmitted
}
}
/* SAMPLE CODE BMP-085
*
uint16_t received_data;
char answer[10];
int32_t UT, X1, X2, B5; // following ds convention
float t;
bmp085_calib_data _bmp085_coeffs;
printf("Hello\r\n");
I2C_init();
printf("I2C Initialized\r\n");
I2C_start(I2C1,SLAVE_ADDRESS << 1, I2C_Direction_Transmitter);
printf("I2C First write\r\n");
I2C_write(I2C1, 0xF4);
printf("I2C Second write\r\n");
I2C_write(I2C1, 0x2E);
printf("I2C stop\r\n");
I2C_stop(I2C1);
printf("I2C Temperature measurment started\r\n");
I2C_start(I2C1,SLAVE_ADDRESS << 1, I2C_Direction_Transmitter);
printf("I2C First write\r\n");
I2C_write(I2C1, 0xF6);
printf("I2C stop\r\n");
I2C_stop(I2C1);
printf("I2C Temperature measurment request sent\r\n");
I2C_start(I2C1, SLAVE_ADDRESS<<1, I2C_Direction_Receiver);
printf("I2C Read request sent\r\n");
received_data = I2C_read_ack(I2C1);
received_data = received_data << 8;
received_data = received_data | I2C_read_ack(I2C1);
printf("I2C data received\r\n");
sprintf(answer,"%d",received_data);
printf("Data: %s\r\n",answer);
* --Imanol
*/