I am having trouble making an i2c comms connection using a Teensy 3.6 and I2C lines SCL0 on pin 7 and SDA0 on pin 8, with an Adafruit 9-DOF IMU breakout, specifically LSM303DLHC and L3GD20 (https://learn.adafruit.com/adafruit-9-dof-imu-breakout).
I can communicate with the device perfectly well on SCL0 pin 19 and SDA0 pin 18, but I run into problems using the non-standard I2C lines.
I have made the necessary changes to use the i2c_t3 library, but this comms stuff is not something I understand well enough to progress further than I have.
My main issues are with the setup. The Adafruit sensor comes with libraries, which I have changed the wire library to use i2c_t3. (I have included a "//Edited JB" comment next to lines I changed)
I would appreciate any help to understand how to set up the communication using the non-standard i2c lines and advice or explanation of what I need to change to fix the problem.
(Before anybody asks, I have triple checked my wiring, including with a multimeter and the hardware side of things seems to be fine)
From what I understand about i2c_t3 I need to change the line:
...to something like: (where LSM303_ADDRESS_ACCEL is the accelerometer address, 0x32)
I don't know if both the mag and accel should be masters, and I don't understand what I2C_RATE does.
The library below includes 3 classes, which each use Wire.begin(); but I thought this line should only be used once, nevermind 3 times, an explanation for this would help a lot!
The program compiles and runs on the Teensy 3.6 returning the following in the Serial monitor:
My .ino file code is below, alongside the relevant library header and cpp files. All original libraries are available from here: https://learn.adafruit.com/adafruit-9-dof-imu-breakout/software
IMU_LSM303DLHC_L3GD20.ino
Adafruit_LSM303_U.h
I can communicate with the device perfectly well on SCL0 pin 19 and SDA0 pin 18, but I run into problems using the non-standard I2C lines.
I have made the necessary changes to use the i2c_t3 library, but this comms stuff is not something I understand well enough to progress further than I have.
My main issues are with the setup. The Adafruit sensor comes with libraries, which I have changed the wire library to use i2c_t3. (I have included a "//Edited JB" comment next to lines I changed)
I would appreciate any help to understand how to set up the communication using the non-standard i2c lines and advice or explanation of what I need to change to fix the problem.
(Before anybody asks, I have triple checked my wiring, including with a multimeter and the hardware side of things seems to be fine)
From what I understand about i2c_t3 I need to change the line:
Code:
Wire.begin();...to something like: (where LSM303_ADDRESS_ACCEL is the accelerometer address, 0x32)
Code:
Wire.begin(I2C_MASTER, LSM303_ADDRESS_ACCEL, I2C_PINS_7_8, I2C_PULLUP_INT, I2C_RATE_400);I don't know if both the mag and accel should be masters, and I don't understand what I2C_RATE does.
The library below includes 3 classes, which each use Wire.begin(); but I thought this line should only be used once, nevermind 3 times, an explanation for this would help a lot!
The program compiles and runs on the Teensy 3.6 returning the following in the Serial monitor:
Code:
Adafruit 9 DOF Pitch/Roll/Heading Example
initSensors
wire begun
Ooops, no LSM303 detected ... Check your wiring! AccelMy .ino file code is below, alongside the relevant library header and cpp files. All original libraries are available from here: https://learn.adafruit.com/adafruit-9-dof-imu-breakout/software
IMU_LSM303DLHC_L3GD20.ino
Code:
#include <i2c_t3.h> //https://github.com/nox771/i2c_t3
#include <Adafruit_Sensor.h>
#include <Adafruit_LSM303_U.h>
#include <Adafruit_L3GD20_U.h>
#include <Adafruit_9DOF.h>
/* Assign a unique ID to the sensors */
Adafruit_9DOF dof = Adafruit_9DOF();
Adafruit_LSM303_Accel_Unified accel = Adafruit_LSM303_Accel_Unified(30301);
Adafruit_LSM303_Mag_Unified mag = Adafruit_LSM303_Mag_Unified(30302);
/* Update this with the correct SLP for accurate altitude measurements */
float seaLevelPressure = SENSORS_PRESSURE_SEALEVELHPA;
void setup(void)
{
pinMode(LED_BUILTIN,OUTPUT);
Serial.begin(115200);
while(!Serial) {};
Serial.println("Adafruit 9 DOF Pitch/Roll/Heading Example");
/* Initialise the sensors */
digitalWrite(LED_BUILTIN,HIGH);
initSensors();
}
void initSensors() //Accel I2C address: 0x32 | LSM303_ADDRESS_ACCEL, Mag I2C address 0x3C | LSM303_ADDRESS_MAG
{
Serial.println("initSensors");
//Wire.begin(I2C_MASTER, 0x00, I2C_PINS_7_8, I2C_PULLUP_INT, I2C_RATE_400); //i2c_mode, address 1, i2c_pins, i2c_pullup, i2c_rate, i2c_op_mode
Serial.println("wire begun");
if(!accel.begin()) //For default I2C lines leave parentheses empty ***************************************
{
/* There was a problem detecting the LSM303 ... check your connections */
Serial.println("Ooops, no LSM303 detected ... Check your wiring! Accel");
while(1);
}
if(!mag.begin())
{
/* There was a problem detecting the LSM303 ... check your connections */
Serial.println("Ooops, no LSM303 detected ... Check your wiring! Mag");
while(1);
}
Serial.println("initSensors complete");
}
(loop code not relevant)Adafruit_LSM303_U.h
Code:
/***************************************************************************
This is a library for the LSM303 Accelerometer and magnentometer/compass
Designed specifically to work with the Adafruit LSM303DLHC Breakout
These displays use I2C to communicate, 2 pins are required to interface.
Adafruit invests time and resources providing this open source code,
please support Adafruit andopen-source hardware by purchasing products
from Adafruit!
Written by Kevin Townsend for Adafruit Industries.
BSD license, all text above must be included in any redistribution
***************************************************************************/
#ifndef __LSM303_H__
#define __LSM303_H__
#if (ARDUINO >= 100)
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
#include <Adafruit_Sensor.h>
#include <i2c_t3.h>
/*=========================================================================
I2C ADDRESS/BITS
-----------------------------------------------------------------------*/
#define LSM303_ADDRESS_ACCEL (0x32 >> 1) // 0011001x
#define LSM303_ADDRESS_MAG (0x3C >> 1) // 0011110x
/*=========================================================================*/
/*=========================================================================
REGISTERS
-----------------------------------------------------------------------*/
typedef enum
{ // DEFAULT TYPE
LSM303_REGISTER_ACCEL_CTRL_REG1_A = 0x20, // 00000111 rw
LSM303_REGISTER_ACCEL_CTRL_REG2_A = 0x21, // 00000000 rw
LSM303_REGISTER_ACCEL_CTRL_REG3_A = 0x22, // 00000000 rw
LSM303_REGISTER_ACCEL_CTRL_REG4_A = 0x23, // 00000000 rw
LSM303_REGISTER_ACCEL_CTRL_REG5_A = 0x24, // 00000000 rw
LSM303_REGISTER_ACCEL_CTRL_REG6_A = 0x25, // 00000000 rw
LSM303_REGISTER_ACCEL_REFERENCE_A = 0x26, // 00000000 r
LSM303_REGISTER_ACCEL_STATUS_REG_A = 0x27, // 00000000 r
LSM303_REGISTER_ACCEL_OUT_X_L_A = 0x28,
LSM303_REGISTER_ACCEL_OUT_X_H_A = 0x29,
LSM303_REGISTER_ACCEL_OUT_Y_L_A = 0x2A,
LSM303_REGISTER_ACCEL_OUT_Y_H_A = 0x2B,
LSM303_REGISTER_ACCEL_OUT_Z_L_A = 0x2C,
LSM303_REGISTER_ACCEL_OUT_Z_H_A = 0x2D,
LSM303_REGISTER_ACCEL_FIFO_CTRL_REG_A = 0x2E,
LSM303_REGISTER_ACCEL_FIFO_SRC_REG_A = 0x2F,
LSM303_REGISTER_ACCEL_INT1_CFG_A = 0x30,
LSM303_REGISTER_ACCEL_INT1_SOURCE_A = 0x31,
LSM303_REGISTER_ACCEL_INT1_THS_A = 0x32,
LSM303_REGISTER_ACCEL_INT1_DURATION_A = 0x33,
LSM303_REGISTER_ACCEL_INT2_CFG_A = 0x34,
LSM303_REGISTER_ACCEL_INT2_SOURCE_A = 0x35,
LSM303_REGISTER_ACCEL_INT2_THS_A = 0x36,
LSM303_REGISTER_ACCEL_INT2_DURATION_A = 0x37,
LSM303_REGISTER_ACCEL_CLICK_CFG_A = 0x38,
LSM303_REGISTER_ACCEL_CLICK_SRC_A = 0x39,
LSM303_REGISTER_ACCEL_CLICK_THS_A = 0x3A,
LSM303_REGISTER_ACCEL_TIME_LIMIT_A = 0x3B,
LSM303_REGISTER_ACCEL_TIME_LATENCY_A = 0x3C,
LSM303_REGISTER_ACCEL_TIME_WINDOW_A = 0x3D
} lsm303AccelRegisters_t;
typedef enum
{
LSM303_REGISTER_MAG_CRA_REG_M = 0x00,
LSM303_REGISTER_MAG_CRB_REG_M = 0x01,
LSM303_REGISTER_MAG_MR_REG_M = 0x02,
LSM303_REGISTER_MAG_OUT_X_H_M = 0x03,
LSM303_REGISTER_MAG_OUT_X_L_M = 0x04,
LSM303_REGISTER_MAG_OUT_Z_H_M = 0x05,
LSM303_REGISTER_MAG_OUT_Z_L_M = 0x06,
LSM303_REGISTER_MAG_OUT_Y_H_M = 0x07,
LSM303_REGISTER_MAG_OUT_Y_L_M = 0x08,
LSM303_REGISTER_MAG_SR_REG_Mg = 0x09,
LSM303_REGISTER_MAG_IRA_REG_M = 0x0A,
LSM303_REGISTER_MAG_IRB_REG_M = 0x0B,
LSM303_REGISTER_MAG_IRC_REG_M = 0x0C,
LSM303_REGISTER_MAG_TEMP_OUT_H_M = 0x31,
LSM303_REGISTER_MAG_TEMP_OUT_L_M = 0x32
} lsm303MagRegisters_t;
/*=========================================================================*/
/*=========================================================================
MAGNETOMETER GAIN SETTINGS
-----------------------------------------------------------------------*/
typedef enum
{
LSM303_MAGGAIN_1_3 = 0x20, // +/- 1.3
LSM303_MAGGAIN_1_9 = 0x40, // +/- 1.9
LSM303_MAGGAIN_2_5 = 0x60, // +/- 2.5
LSM303_MAGGAIN_4_0 = 0x80, // +/- 4.0
LSM303_MAGGAIN_4_7 = 0xA0, // +/- 4.7
LSM303_MAGGAIN_5_6 = 0xC0, // +/- 5.6
LSM303_MAGGAIN_8_1 = 0xE0 // +/- 8.1
} lsm303MagGain;
/*=========================================================================*/
/*=========================================================================
MAGNETOMETER UPDATE RATE SETTINGS
-----------------------------------------------------------------------*/
typedef enum
{
LSM303_MAGRATE_0_7 = 0x00, // 0.75 Hz
LSM303_MAGRATE_1_5 = 0x01, // 1.5 Hz
LSM303_MAGRATE_3_0 = 0x62, // 3.0 Hz
LSM303_MAGRATE_7_5 = 0x03, // 7.5 Hz
LSM303_MAGRATE_15 = 0x04, // 15 Hz
LSM303_MAGRATE_30 = 0x05, // 30 Hz
LSM303_MAGRATE_75 = 0x06, // 75 Hz
LSM303_MAGRATE_220 = 0x07 // 200 Hz
} lsm303MagRate;
/*=========================================================================*/
/*=========================================================================
INTERNAL MAGNETOMETER DATA TYPE
-----------------------------------------------------------------------*/
typedef struct lsm303MagData_s
{
int16_t x;
int16_t y;
int16_t z;
} lsm303MagData;
/*=========================================================================*/
/*=========================================================================
INTERNAL ACCELERATION DATA TYPE
-----------------------------------------------------------------------*/
typedef struct lsm303AccelData_s
{
int16_t x;
int16_t y;
int16_t z;
} lsm303AccelData;
/*=========================================================================*/
/*=========================================================================
CHIP ID
-----------------------------------------------------------------------*/
#define LSM303_ID (0b11010100)
/*=========================================================================*/
/* Unified sensor driver for the accelerometer */
class Adafruit_LSM303_Accel_Unified : public Adafruit_Sensor
{
public:
Adafruit_LSM303_Accel_Unified(int32_t sensorID = -1);
bool begin(void);
bool getEvent(sensors_event_t*);
void getSensor(sensor_t*);
lsm303AccelData raw; // Last read accelerometer data will be available here
private:
int32_t _sensorID;
void write8(byte address, byte reg, byte value);
byte read8(byte address, byte reg);
void read(void);
};
/* Unified sensor driver for the magnetometer */
class Adafruit_LSM303_Mag_Unified : public Adafruit_Sensor
{
public:
Adafruit_LSM303_Mag_Unified(int32_t sensorID = -1);
bool begin(void);
void enableAutoRange(bool enable);
void setMagGain(lsm303MagGain gain);
void setMagRate(lsm303MagRate rate);
bool getEvent(sensors_event_t*);
void getSensor(sensor_t*);
lsm303MagData raw; // Last read magnetometer data will be available here
lsm303MagGain magGain;
bool autoRangeEnabled;
private:
int32_t _sensorID;
void write8(byte address, byte reg, byte value);
byte read8(byte address, byte reg);
void read(void);
};
/* Non Unified (old) driver for compatibility reasons */
class Adafruit_LSM303
{
public:
bool begin(void);
void read(void);
void setMagGain(lsm303MagGain gain);
lsm303AccelData accelData; // Last read accelerometer data will be available here
lsm303MagData magData; // Last read magnetometer data will be available here
void write8(byte address, byte reg, byte value);
byte read8(byte address, byte reg);
};
#endif
Code:
/***************************************************************************
This is a library for the LSM303 Accelerometer and magnentometer/compass
Designed specifically to work with the Adafruit LSM303DLHC Breakout
These displays use I2C to communicate, 2 pins are required to interface.
Adafruit invests time and resources providing this open source code,
please support Adafruit andopen-source hardware by purchasing products
from Adafruit!
Written by Kevin Townsend for Adafruit Industries.
BSD license, all text above must be included in any redistribution
***************************************************************************/
#if ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
#include <i2c_t3.h> //Edited JB
#include <limits.h>
#include "Adafruit_LSM303_U.h"
/* enabling this #define will enable the debug print blocks
#define LSM303_DEBUG
*/
static float _lsm303Accel_MG_LSB = 0.001F; // 1, 2, 4 or 12 mg per lsb
static float _lsm303Mag_Gauss_LSB_XY = 1100.0F; // Varies with gain
static float _lsm303Mag_Gauss_LSB_Z = 980.0F; // Varies with gain
/***************************************************************************
ACCELEROMETER
***************************************************************************/
/***************************************************************************
PRIVATE FUNCTIONS
***************************************************************************/
/**************************************************************************/
/*!
@brief Abstract away platform differences in Arduino wire library
*/
/**************************************************************************/
void Adafruit_LSM303_Accel_Unified::write8(byte address, byte reg, byte value)
{
Wire.beginTransmission(address);
#if ARDUINO >= 100
Wire.write((uint8_t)reg);
Wire.write((uint8_t)value);
#else
Wire.send(reg);
Wire.send(value);
#endif
Wire.endTransmission();
}
/**************************************************************************/
/*!
@brief Abstract away platform differences in Arduino wire library
*/
/**************************************************************************/
byte Adafruit_LSM303_Accel_Unified::read8(byte address, byte reg)
{
byte value;
Wire.beginTransmission(address);
#if ARDUINO >= 100
Wire.write((uint8_t)reg);
#else
Wire.send(reg);
#endif
Wire.endTransmission();
Wire.requestFrom(address, (byte)1);
#if ARDUINO >= 100
value = Wire.read();
#else
value = Wire.receive();
#endif
Wire.endTransmission();
return value;
}
/**************************************************************************/
/*!
@brief Reads the raw data from the sensor
*/
/**************************************************************************/
void Adafruit_LSM303_Accel_Unified::read()
{
// Read the accelerometer
Wire.beginTransmission((byte)LSM303_ADDRESS_ACCEL);
#if ARDUINO >= 100
Wire.write(LSM303_REGISTER_ACCEL_OUT_X_L_A | 0x80);
#else
Wire.send(LSM303_REGISTER_ACCEL_OUT_X_L_A | 0x80);
#endif
Wire.endTransmission();
Wire.requestFrom((byte)LSM303_ADDRESS_ACCEL, (byte)6);
// Wait around until enough data is available
while (Wire.available() < 6);
#if ARDUINO >= 100
uint8_t xlo = Wire.read();
uint8_t xhi = Wire.read();
uint8_t ylo = Wire.read();
uint8_t yhi = Wire.read();
uint8_t zlo = Wire.read();
uint8_t zhi = Wire.read();
#else
uint8_t xlo = Wire.receive();
uint8_t xhi = Wire.receive();
uint8_t ylo = Wire.receive();
uint8_t yhi = Wire.receive();
uint8_t zlo = Wire.receive();
uint8_t zhi = Wire.receive();
#endif
// Shift values to create properly formed integer (low byte first)
raw.x = (int16_t)(xlo | (xhi << 8)) >> 4;
raw.y = (int16_t)(ylo | (yhi << 8)) >> 4;
raw.z = (int16_t)(zlo | (zhi << 8)) >> 4;
}
/***************************************************************************
CONSTRUCTOR
***************************************************************************/
/**************************************************************************/
/*!
@brief Instantiates a new Adafruit_LSM303 class
*/
/**************************************************************************/
Adafruit_LSM303_Accel_Unified::Adafruit_LSM303_Accel_Unified(int32_t sensorID) {
_sensorID = sensorID;
// Clear the raw accel data
raw.x = 0;
raw.y = 0;
raw.z = 0;
}
/***************************************************************************
PUBLIC FUNCTIONS
***************************************************************************/
/**************************************************************************/
/*!
@brief Setups the HW
*/
/**************************************************************************/
bool Adafruit_LSM303_Accel_Unified::begin()
{
// Enable I2C
//Wire.begin();
Wire.begin(I2C_MASTER, LSM303_ADDRESS_ACCEL, I2C_PINS_7_8, I2C_PULLUP_INT, I2C_RATE_400); //Edited JB
// Enable the accelerometer (100Hz)
write8(LSM303_ADDRESS_ACCEL, LSM303_REGISTER_ACCEL_CTRL_REG1_A, 0x57);
// LSM303DLHC has no WHOAMI register so read CTRL_REG1_A back to check
// if we are connected or not
uint8_t reg1_a = read8(LSM303_ADDRESS_ACCEL, LSM303_REGISTER_ACCEL_CTRL_REG1_A);
if (reg1_a != 0x57)
{
return false;
}
return true;
}
/**************************************************************************/
/*!
@brief Gets the most recent sensor event
*/
/**************************************************************************/
bool Adafruit_LSM303_Accel_Unified::getEvent(sensors_event_t *event) {
/* Clear the event */
memset(event, 0, sizeof(sensors_event_t));
/* Read new data */
read();
event->version = sizeof(sensors_event_t);
event->sensor_id = _sensorID;
event->type = SENSOR_TYPE_ACCELEROMETER;
event->timestamp = millis();
event->acceleration.x = (float)raw.x * _lsm303Accel_MG_LSB * SENSORS_GRAVITY_STANDARD;
event->acceleration.y = (float)raw.y * _lsm303Accel_MG_LSB * SENSORS_GRAVITY_STANDARD;
event->acceleration.z = (float)raw.z * _lsm303Accel_MG_LSB * SENSORS_GRAVITY_STANDARD;
return true;
}
/**************************************************************************/
/*!
@brief Gets the sensor_t data
*/
/**************************************************************************/
void Adafruit_LSM303_Accel_Unified::getSensor(sensor_t *sensor) {
/* Clear the sensor_t object */
memset(sensor, 0, sizeof(sensor_t));
/* Insert the sensor name in the fixed length char array */
strncpy (sensor->name, "LSM303", sizeof(sensor->name) - 1);
sensor->name[sizeof(sensor->name)- 1] = 0;
sensor->version = 1;
sensor->sensor_id = _sensorID;
sensor->type = SENSOR_TYPE_ACCELEROMETER;
sensor->min_delay = 0;
sensor->max_value = 0.0F; // TBD
sensor->min_value = 0.0F; // TBD
sensor->resolution = 0.0F; // TBD
}
/***************************************************************************
MAGNETOMETER
***************************************************************************/
/***************************************************************************
PRIVATE FUNCTIONS
***************************************************************************/
/**************************************************************************/
/*!
@brief Abstract away platform differences in Arduino wire library
*/
/**************************************************************************/
void Adafruit_LSM303_Mag_Unified::write8(byte address, byte reg, byte value)
{
Wire.beginTransmission(address);
#if ARDUINO >= 100
Wire.write((uint8_t)reg);
Wire.write((uint8_t)value);
#else
Wire.send(reg);
Wire.send(value);
#endif
Wire.endTransmission();
}
/**************************************************************************/
/*!
@brief Abstract away platform differences in Arduino wire library
*/
/**************************************************************************/
byte Adafruit_LSM303_Mag_Unified::read8(byte address, byte reg)
{
byte value;
Wire.beginTransmission(address);
#if ARDUINO >= 100
Wire.write((uint8_t)reg);
#else
Wire.send(reg);
#endif
Wire.endTransmission();
Wire.requestFrom(address, (byte)1);
#if ARDUINO >= 100
value = Wire.read();
#else
value = Wire.receive();
#endif
Wire.endTransmission();
return value;
}
/**************************************************************************/
/*!
@brief Reads the raw data from the sensor
*/
/**************************************************************************/
void Adafruit_LSM303_Mag_Unified::read()
{
// Read the magnetometer
Wire.beginTransmission((byte)LSM303_ADDRESS_MAG);
#if ARDUINO >= 100
Wire.write(LSM303_REGISTER_MAG_OUT_X_H_M);
#else
Wire.send(LSM303_REGISTER_MAG_OUT_X_H_M);
#endif
Wire.endTransmission();
Wire.requestFrom((byte)LSM303_ADDRESS_MAG, (byte)6);
// Wait around until enough data is available
while (Wire.available() < 6);
// Note high before low (different than accel)
#if ARDUINO >= 100
uint8_t xhi = Wire.read();
uint8_t xlo = Wire.read();
uint8_t zhi = Wire.read();
uint8_t zlo = Wire.read();
uint8_t yhi = Wire.read();
uint8_t ylo = Wire.read();
#else
uint8_t xhi = Wire.receive();
uint8_t xlo = Wire.receive();
uint8_t zhi = Wire.receive();
uint8_t zlo = Wire.receive();
uint8_t yhi = Wire.receive();
uint8_t ylo = Wire.receive();
#endif
// Shift values to create properly formed integer (low byte first)
raw.x = (int16_t)(xlo | ((int16_t)xhi << 8));
raw.y = (int16_t)(ylo | ((int16_t)yhi << 8));
raw.z = (int16_t)(zlo | ((int16_t)zhi << 8));
}
/***************************************************************************
CONSTRUCTOR
***************************************************************************/
/**************************************************************************/
/*!
@brief Instantiates a new Adafruit_LSM303 class
*/
/**************************************************************************/
Adafruit_LSM303_Mag_Unified::Adafruit_LSM303_Mag_Unified(int32_t sensorID) {
_sensorID = sensorID;
autoRangeEnabled = false;
// Clear the raw mag data
raw.x = 0;
raw.y = 0;
raw.z = 0;
}
/***************************************************************************
PUBLIC FUNCTIONS
***************************************************************************/
/**************************************************************************/
/*!
@brief Setups the HW
*/
/**************************************************************************/
bool Adafruit_LSM303_Mag_Unified::begin()
{
// Enable I2C
//Wire.begin();
Wire.begin(I2C_MASTER, LSM303_ADDRESS_MAG, I2C_PINS_7_8, I2C_PULLUP_INT, I2C_RATE_400); //Edited JB
// Enable the magnetometer
write8(LSM303_ADDRESS_MAG, LSM303_REGISTER_MAG_MR_REG_M, 0x00);
// LSM303DLHC has no WHOAMI register so read CRA_REG_M to check
// the default value (0b00010000/0x10)
uint8_t reg1_a = read8(LSM303_ADDRESS_MAG, LSM303_REGISTER_MAG_CRA_REG_M);
if (reg1_a != 0x10)
{
return false;
}
// Set the gain to a known level
setMagGain(LSM303_MAGGAIN_1_3);
return true;
}
/**************************************************************************/
/*!
@brief Enables or disables auto-ranging
*/
/**************************************************************************/
void Adafruit_LSM303_Mag_Unified::enableAutoRange(bool enabled)
{
autoRangeEnabled = enabled;
}
/**************************************************************************/
/*!
@brief Sets the magnetometer's gain
*/
/**************************************************************************/
void Adafruit_LSM303_Mag_Unified::setMagGain(lsm303MagGain gain)
{
write8(LSM303_ADDRESS_MAG, LSM303_REGISTER_MAG_CRB_REG_M, (byte)gain);
magGain = gain;
switch(gain)
{
case LSM303_MAGGAIN_1_3:
_lsm303Mag_Gauss_LSB_XY = 1100;
_lsm303Mag_Gauss_LSB_Z = 980;
break;
case LSM303_MAGGAIN_1_9:
_lsm303Mag_Gauss_LSB_XY = 855;
_lsm303Mag_Gauss_LSB_Z = 760;
break;
case LSM303_MAGGAIN_2_5:
_lsm303Mag_Gauss_LSB_XY = 670;
_lsm303Mag_Gauss_LSB_Z = 600;
break;
case LSM303_MAGGAIN_4_0:
_lsm303Mag_Gauss_LSB_XY = 450;
_lsm303Mag_Gauss_LSB_Z = 400;
break;
case LSM303_MAGGAIN_4_7:
_lsm303Mag_Gauss_LSB_XY = 400;
_lsm303Mag_Gauss_LSB_Z = 355;
break;
case LSM303_MAGGAIN_5_6:
_lsm303Mag_Gauss_LSB_XY = 330;
_lsm303Mag_Gauss_LSB_Z = 295;
break;
case LSM303_MAGGAIN_8_1:
_lsm303Mag_Gauss_LSB_XY = 230;
_lsm303Mag_Gauss_LSB_Z = 205;
break;
}
}
/**************************************************************************/
/*!
@brief Sets the magnetometer's update rate
*/
/**************************************************************************/
void Adafruit_LSM303_Mag_Unified::setMagRate(lsm303MagRate rate)
{
byte reg_m = ((byte)rate & 0x07) << 2;
write8(LSM303_ADDRESS_MAG, LSM303_REGISTER_MAG_CRA_REG_M, reg_m);
}
/**************************************************************************/
/*!
@brief Gets the most recent sensor event
*/
/**************************************************************************/
bool Adafruit_LSM303_Mag_Unified::getEvent(sensors_event_t *event) {
bool readingValid = false;
/* Clear the event */
memset(event, 0, sizeof(sensors_event_t));
while(!readingValid)
{
uint8_t reg_mg = read8(LSM303_ADDRESS_MAG, LSM303_REGISTER_MAG_SR_REG_Mg);
if (!(reg_mg & 0x1)) {
return false;
}
/* Read new data */
read();
/* Make sure the sensor isn't saturating if auto-ranging is enabled */
if (!autoRangeEnabled)
{
readingValid = true;
}
else
{
#ifdef LSM303_DEBUG
Serial.print(raw.x); Serial.print(" ");
Serial.print(raw.y); Serial.print(" ");
Serial.print(raw.z); Serial.println(" ");
#endif
/* Check if the sensor is saturating or not */
if ( (raw.x >= 2040) | (raw.x <= -2040) |
(raw.y >= 2040) | (raw.y <= -2040) |
(raw.z >= 2040) | (raw.z <= -2040) )
{
/* Saturating .... increase the range if we can */
switch(magGain)
{
case LSM303_MAGGAIN_5_6:
setMagGain(LSM303_MAGGAIN_8_1);
readingValid = false;
#ifdef LSM303_DEBUG
Serial.println("Changing range to +/- 8.1");
#endif
break;
case LSM303_MAGGAIN_4_7:
setMagGain(LSM303_MAGGAIN_5_6);
readingValid = false;
#ifdef LSM303_DEBUG
Serial.println("Changing range to +/- 5.6");
#endif
break;
case LSM303_MAGGAIN_4_0:
setMagGain(LSM303_MAGGAIN_4_7);
readingValid = false;
#ifdef LSM303_DEBUG
Serial.println("Changing range to +/- 4.7");
#endif
break;
case LSM303_MAGGAIN_2_5:
setMagGain(LSM303_MAGGAIN_4_0);
readingValid = false;
#ifdef LSM303_DEBUG
Serial.println("Changing range to +/- 4.0");
#endif
break;
case LSM303_MAGGAIN_1_9:
setMagGain(LSM303_MAGGAIN_2_5);
readingValid = false;
#ifdef LSM303_DEBUG
Serial.println("Changing range to +/- 2.5");
#endif
break;
case LSM303_MAGGAIN_1_3:
setMagGain(LSM303_MAGGAIN_1_9);
readingValid = false;
#ifdef LSM303_DEBUG
Serial.println("Changing range to +/- 1.9");
#endif
break;
default:
readingValid = true;
break;
}
}
else
{
/* All values are withing range */
readingValid = true;
}
}
}
event->version = sizeof(sensors_event_t);
event->sensor_id = _sensorID;
event->type = SENSOR_TYPE_MAGNETIC_FIELD;
event->timestamp = millis();
event->magnetic.x = (float)raw.x / _lsm303Mag_Gauss_LSB_XY * SENSORS_GAUSS_TO_MICROTESLA;
event->magnetic.y = (float)raw.y / _lsm303Mag_Gauss_LSB_XY * SENSORS_GAUSS_TO_MICROTESLA;
event->magnetic.z = (float)raw.z / _lsm303Mag_Gauss_LSB_Z * SENSORS_GAUSS_TO_MICROTESLA;
return true;
}
/**************************************************************************/
/*!
@brief Gets the sensor_t data
*/
/**************************************************************************/
void Adafruit_LSM303_Mag_Unified::getSensor(sensor_t *sensor) {
/* Clear the sensor_t object */
memset(sensor, 0, sizeof(sensor_t));
/* Insert the sensor name in the fixed length char array */
strncpy (sensor->name, "LSM303", sizeof(sensor->name) - 1);
sensor->name[sizeof(sensor->name)- 1] = 0;
sensor->version = 1;
sensor->sensor_id = _sensorID;
sensor->type = SENSOR_TYPE_MAGNETIC_FIELD;
sensor->min_delay = 0;
sensor->max_value = 0.0F; // TBD
sensor->min_value = 0.0F; // TBD
sensor->resolution = 0.0F; // TBD
}
/* --- The code below is no longer maintained and provided solely for */
/* --- compatibility reasons! */
/***************************************************************************
DEPRECATED (NON UNIFIED) DRIVER (Adafruit_LSM303.c/h)
***************************************************************************/
/***************************************************************************
CONSTRUCTOR
***************************************************************************/
bool Adafruit_LSM303::begin()
{
//Wire.begin();
Wire.begin(I2C_MASTER, 0x00, I2C_PINS_7_8, I2C_PULLUP_INT, I2C_RATE_400); //Edited JB
//Not sure about which address this should be
// Enable the accelerometer
write8(LSM303_ADDRESS_ACCEL, LSM303_REGISTER_ACCEL_CTRL_REG1_A, 0x27);
// Enable the magnetometer
write8(LSM303_ADDRESS_MAG, LSM303_REGISTER_MAG_MR_REG_M, 0x00);
return true;
}
/***************************************************************************
PUBLIC FUNCTIONS
***************************************************************************/
void Adafruit_LSM303::read()
{
// Read the accelerometer
Wire.beginTransmission((byte)LSM303_ADDRESS_ACCEL);
Wire.write(LSM303_REGISTER_ACCEL_OUT_X_L_A | 0x80);
Wire.endTransmission();
Wire.requestFrom((byte)LSM303_ADDRESS_ACCEL, (byte)6);
// Wait around until enough data is available
while (Wire.available() < 6);
uint8_t xlo = Wire.read();
uint8_t xhi = Wire.read();
uint8_t ylo = Wire.read();
uint8_t yhi = Wire.read();
uint8_t zlo = Wire.read();
uint8_t zhi = Wire.read();
// Shift values to create properly formed integer (low byte first)
accelData.x = (int16_t)((uint16_t)xlo | ((uint16_t)xhi << 8)) >> 4;
accelData.y = (int16_t)((uint16_t)ylo | ((uint16_t)yhi << 8)) >> 4;
accelData.z = (int16_t)((uint16_t)zlo | ((uint16_t)zhi << 8)) >> 4;
// Read the magnetometer
Wire.beginTransmission((byte)LSM303_ADDRESS_MAG);
Wire.write(LSM303_REGISTER_MAG_OUT_X_H_M);
Wire.endTransmission();
Wire.requestFrom((byte)LSM303_ADDRESS_MAG, (byte)6);
// Wait around until enough data is available
while (Wire.available() < 6);
// Note high before low (different than accel)
xhi = Wire.read();
xlo = Wire.read();
zhi = Wire.read();
zlo = Wire.read();
yhi = Wire.read();
ylo = Wire.read();
// Shift values to create properly formed integer (low byte first)
magData.x = (int16_t)((uint16_t)xlo | ((uint16_t)xhi << 8));
magData.y = (int16_t)((uint16_t)ylo | ((uint16_t)yhi << 8));
magData.z = (int16_t)((uint16_t)zlo | ((uint16_t)zhi << 8));
}
void Adafruit_LSM303::setMagGain(lsm303MagGain gain)
{
write8(LSM303_ADDRESS_MAG, LSM303_REGISTER_MAG_CRB_REG_M, (byte)gain);
}
/***************************************************************************
PRIVATE FUNCTIONS
***************************************************************************/
void Adafruit_LSM303::write8(byte address, byte reg, byte value)
{
Wire.beginTransmission(address);
Wire.write(reg);
Wire.write(value);
Wire.endTransmission();
}
byte Adafruit_LSM303::read8(byte address, byte reg)
{
byte value;
Wire.beginTransmission(address);
Wire.write(reg);
Wire.endTransmission();
Wire.requestFrom(address, (byte)1);
value = Wire.read();
Wire.endTransmission();
return value;
}