AMTS/Mieke/SW/MT/bma.c
2018-03-18 23:43:59 +01:00

84 lines
2.4 KiB
C

#include "bma.h"
void init_bma(void)
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
GPIO_InitTypeDef gpio;
GPIO_StructInit(&gpio);
// SCL
gpio.GPIO_Mode = GPIO_Mode_AF_PP;
gpio.GPIO_Pin = GPIO_Pin_6;
GPIO_Init(GPIOB, &gpio);
// SDA
gpio.GPIO_Mode = GPIO_Mode_AF_OD;
gpio.GPIO_Pin = GPIO_Pin_7;
GPIO_Init(GPIOB, &gpio);
I2C_InitTypeDef i2c;
I2C_StructInit(&i2c);
i2c.I2C_ClockSpeed = 400000;
I2C_Init(I2C1, &i2c);
I2C_Cmd(I2C1, ENABLE);
}
void run_bma(float acc_f[3])
{
int16_t acc[3];
// Select first register address to read
I2C_GenerateSTART(I2C1, ENABLE);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
I2C_Send7bitAddress(I2C1, BMA_ADDR, I2C_Direction_Transmitter);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
I2C_SendData(I2C1, 0x02);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
I2C_GenerateSTOP(I2C1, ENABLE);
I2C_GenerateSTART(I2C1, ENABLE);
I2C_AcknowledgeConfig(I2C1, ENABLE);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
I2C_Send7bitAddress(I2C1, BMA_ADDR, I2C_Direction_Receiver);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));
// X LSB
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
acc[0] = (I2C_ReceiveData(I2C1) & 0xC0) >> 6;
// X MSB
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
acc[0] = (I2C_ReceiveData(I2C1) & 0xFF) << 2 | (acc[0] & 0x0003);
if(acc[0] & 0x0200) acc[0] |= 0xFC00;
// Y LSB
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
acc[1] = (I2C_ReceiveData(I2C1) & 0xC0) >> 6;
// Y MSB
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
acc[1] = (I2C_ReceiveData(I2C1) & 0xFF) << 2 | (acc[1] & 0x0003);
if(acc[1] & 0x0200) acc[1] |= 0xFC00;
// Z LSB
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
acc[2] = (I2C_ReceiveData(I2C1) & 0xC0) >> 6;
// Z MSB
I2C_AcknowledgeConfig(I2C1, DISABLE);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
acc[2] = (I2C_ReceiveData(I2C1) & 0xFF) << 2 | (acc[2] & 0x0003);
if(acc[2] & 0x0200) acc[2] |= 0xFC00;
I2C_GenerateSTOP(I2C1, ENABLE);
acc_f[0] = 2.0f * ((float)acc[0]/512);
acc_f[1] = 2.0f * ((float)acc[1]/512);
acc_f[2] = 2.0f * ((float)acc[2]/512);
}
void deinit_bma(void)
{
I2C_Cmd(I2C1, DISABLE);
I2C_DeInit(I2C1);
}