Sorry for the nube question, but I am really struggling to try and get my IMU data from my MPU9250, to send constant notifications through BLE using the NRF8001. The hardware that I am using is the TinyShield Nordic board from tinycircuits.
I feel like this should be easy, but when I connect BLElite I only get 0 as the notification.
Is there anyone out there who could help me? This is the thing that is currently holding me back, and I would love to get it working soon.
Thanks for all your help, bellow is the code that I am trying to use in order to read and send the data from the IMU through BLE.
#include <Wire.h>
#define MPU9250_ADDRESS 0x69
#define MAG_ADDRESS 0x0C
#define GYRO_FULL_SCALE_250_DPS 0x00
#define GYRO_FULL_SCALE_500_DPS 0x08
#define GYRO_FULL_SCALE_1000_DPS 0x10
#define GYRO_FULL_SCALE_2000_DPS 0x18
#define ACC_FULL_SCALE_2_G 0x00
#define ACC_FULL_SCALE_4_G 0x08
#define ACC_FULL_SCALE_8_G 0x10
#define ACC_FULL_SCALE_16_G 0x18
#define BLE_DEBUG 1
#include "SPI.h"
#include "lib_aci.h"
#include "aci_setup.h"
#include "uart_over_ble.h"
#include "services.h"
uint8_t ble_rx_buffer[21];
uint8_t ble_rx_buffer_len = 0;
//when using this project in the Arduino IDE, delete the following include and rename UART.h to UART.ino
#include "UART.h"
// This function read Nbytes bytes from I2C device at address Address.
// Put read bytes starting at register Register in the Data array.
void I2Cread(uint8_t Address, uint8_t Register, uint8_t Nbytes, uint8_t* Data)
{
// Set register address
Wire.beginTransmission(Address);
Wire.write(Register);
Wire.endTransmission();
// Read Nbytes
Wire.requestFrom(Address, Nbytes);
uint8_t index=0;
while (Wire.available())
Data[index++]=Wire.read();
}
// Write a byte (Data) in device (Address) at register (Register)
void I2CwriteByte(uint8_t Address, uint8_t Register, uint8_t Data)
{
// Set register address
Wire.beginTransmission(Address);
Wire.write(Register);
Wire.write(Data);
Wire.endTransmission();
}
void setup(void)
{
Serial.begin(9600);
Wire.begin();
// Main loop, read and display data
BLEsetup();
// Set accelerometers low pass filter at 5Hz
I2CwriteByte(MPU9250_ADDRESS,29,0x06);
// Set gyroscope low pass filter at 5Hz
I2CwriteByte(MPU9250_ADDRESS,26,0x06);
// Configure gyroscope range
I2CwriteByte(MPU9250_ADDRESS,27,GYRO_FULL_SCALE_1000_DPS);
// Configure accelerometers range
I2CwriteByte(MPU9250_ADDRESS,28,ACC_FULL_SCALE_4_G);
// Set by pass mode for the magnetometers
I2CwriteByte(MPU9250_ADDRESS,0x37,0x02);
// Request continuous magnetometer measurements in 16 bits
I2CwriteByte(MAG_ADDRESS,0x0A,0x16);
}
void loop() {
aci_loop();//Process any ACI commands or events
// ____________________________________
// ::: accelerometer and gyroscope :::
// Read accelerometer and gyroscope
uint8_t Buf[14];
I2Cread(MPU9250_ADDRESS,0x3B,14,Buf);
// _____________________
// ::: Magnetometer :::
// Read register Status 1 and wait for the DRDY: Data Ready
uint8_t ST1;
do
{
I2Cread(MAG_ADDRESS,0x02,1,&ST1);
}
while (!(ST1&0x01));
// Read magnetometer data
uint8_t Mag[7];
I2Cread(MAG_ADDRESS,0x03,7,Mag);
// Create 16 bits values from 8 bits data
// Accelerometer
int16_t ax=-(Buf[0]<<8 | Buf[1]);
int16_t ay=-(Buf[2]<<8 | Buf[3]);
int16_t az=Buf[4]<<8 | Buf[5];
// Gyroscope
int16_t gx=-(Buf[8]<<8 | Buf[9]);
int16_t gy=-(Buf[10]<<8 | Buf[11]);
int16_t gz=Buf[12]<<8 | Buf[13];
// Magnetometer
int16_t mx=-(Mag[3]<<8 | Mag[2]);
int16_t my=-(Mag[1]<<8 | Mag[0]);
int16_t mz=-(Mag[5]<<8 | Mag[4]);
// Serial.println(msg);
if(ble_rx_buffer_len){
Serial.println(ble_rx_buffer_len);
Serial.println((char*)ble_rx_buffer);
// Display values
// Accelerometer
String msg = String(ax,DEC);
msg += ("\t");
msg += String(ay,DEC);
msg += ("\t");
msg += String(az,DEC);
msg += ("\t");
// Gyroscope
msg += String(gx,DEC);
msg += ("\t");
msg += String(gy,DEC);
msg += ("\t");
msg += String(gz,DEC);
msg += ("\t");
// Magnetometer
msg += String(mx+200,DEC);
msg += ("\t");
msg += String(my-70,DEC);
msg += ("\t");
msg += String(mz-700,DEC);
msg += ("\t");
uint8_t sendBuffer[15];
uint8_t length = 15;
msg.getBytes(sendBuffer, 15);
lib_aci_send_data(PIPE_UART_OVER_BTLE_UART_TX_TX, sendBuffer, length);
length=0;
}
// delay(250);//We'll make sure we're over the 64ms update time set on the BMA250
}
