/* 09/23/2017 Copyright Tlera Corporation
Created by Kris Winer
This sketch uses SDA/SCL on pins 21/20 (Butterfly default), respectively, and it uses the Butterfly STM32L433CU Breakout Board.
The LSM6DSM is a sensor hub with embedded accel and gyro, here used as 6 DoF in a 9 DoF absolute orientation solution.
Library may be used freely and without limit with attribution.
*/
#include "LSM6DSM.h"
LSM6DSM::LSM6DSM(uint8_t intPin1, uint8_t intPin2)
{
pinMode(intPin1, INPUT);
_intPin1 = intPin1;
pinMode(intPin2, INPUT);
_intPin2 = intPin2;
}
uint8_t LSM6DSM::getChipID()
{
uint8_t c = readByte(LSM6DSM_ADDRESS, LSM6DSM_WHO_AM_I);
return c;
}
float LSM6DSM::getAres(uint8_t Ascale) {
switch (Ascale)
{
// Possible accelerometer scales (and their register bit settings) are:
// 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs (11).
// Here's a bit of an algorithm to calculate DPS/(ADC tick) based on that 2-bit value:
case AFS_2G:
_aRes = 2.0f/32768.0f;
return _aRes;
break;
case AFS_4G:
_aRes = 4.0f/32768.0f;
return _aRes;
break;
case AFS_8G:
_aRes = 8.0f/32768.0f;
return _aRes;
break;
case AFS_16G:
_aRes = 16.0f/32768.0f;
return _aRes;
break;
}
}
float LSM6DSM::getGres(uint8_t Gscale) {
switch (Gscale)
{
// Possible gyro scales (and their register bit settings) are:
// 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11).
case GFS_245DPS:
_gRes = 245.0f/32768.0f;
return _gRes;
break;
case GFS_500DPS:
_gRes = 500.0f/32768.0f;
return _gRes;
break;
case GFS_1000DPS:
_gRes = 1000.0f/32768.0f;
return _gRes;
break;
case GFS_2000DPS:
_gRes = 2000.0f/32768.0f;
return _gRes;
break;
}
}
void LSM6DSM::reset()
{
// reset device
uint8_t temp = readByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL3_C);
writeByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL3_C, temp | 0x01); // Set bit 0 to 1 to reset LSM6DSM
delay(100); // Wait for all registers to reset
}
void LSM6DSM::init(uint8_t Ascale, uint8_t Gscale, uint8_t AODR, uint8_t GODR)
{
writeByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL1_XL, AODR << 4 | Ascale << 2);
writeByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL2_G, GODR << 4 | Gscale << 2);
uint8_t temp = readByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL3_C);
// enable block update (bit 6 = 1), auto-increment registers (bit 2 = 1)
writeByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL3_C, temp | 0x40 | 0x04);
// by default, interrupts active HIGH, push pull, little endian data
// (can be changed by writing to bits 5, 4, and 1, resp to above register)
// enable accel LP2 (bit 7 = 1), set LP2 tp ODR/9 (bit 6 = 1), enable input_composite (bit 3) for low noise
writeByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL8_XL, 0x80 | 0x40 | 0x08 );
// interrupt handling
writeByte(LSM6DSM_ADDRESS, LSM6DSM_DRDY_PULSE_CFG, 0x80); // latch interrupt until data read
writeByte(LSM6DSM_ADDRESS, LSM6DSM_INT1_CTRL, 0x40); // enable significant motion interrupts on INT1
writeByte(LSM6DSM_ADDRESS, LSM6DSM_INT2_CTRL, 0x03); // enable accel/gyro data ready interrupts on INT2
}
void LSM6DSM::selfTest()
{
int16_t temp[7] = {0, 0, 0, 0, 0, 0, 0};
int16_t accelPTest[3] = {0, 0, 0}, accelNTest[3] = {0, 0, 0}, gyroPTest[3] = {0, 0, 0}, gyroNTest[3] = {0, 0, 0};
int16_t accelNom[3] = {0, 0, 0}, gyroNom[3] = {0, 0, 0};
readData(temp);
accelNom[0] = temp[4];
accelNom[1] = temp[5];
accelNom[2] = temp[6];
gyroNom[0] = temp[1];
gyroNom[1] = temp[2];
gyroNom[2] = temp[3];
writeByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL5_C, 0x01); // positive accel self test
delay(100); // let accel respond
readData(temp);
accelPTest[0] = temp[4];
accelPTest[1] = temp[5];
accelPTest[2] = temp[6];
writeByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL5_C, 0x03); // negative accel self test
delay(100); // let accel respond
readData(temp);
accelNTest[0] = temp[4];
accelNTest[1] = temp[5];
accelNTest[2] = temp[6];
writeByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL5_C, 0x04); // positive gyro self test
delay(100); // let gyro respond
readData(temp);
gyroPTest[0] = temp[1];
gyroPTest[1] = temp[2];
gyroPTest[2] = temp[3];
writeByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL5_C, 0x0C); // negative gyro self test
delay(100); // let gyro respond
readData(temp);
gyroNTest[0] = temp[1];
gyroNTest[1] = temp[2];
gyroNTest[2] = temp[3];
writeByte(LSM6DSM_ADDRESS, LSM6DSM_CTRL5_C, 0x00); // normal mode
delay(100); // let accel and gyro respond
Serial.println("Accel Self Test:");
Serial.print("+Ax results:"); Serial.print( (accelPTest[0] - accelNom[0]) * _aRes * 1000.0); Serial.println(" mg");
Serial.print("-Ax results:"); Serial.println((accelNTest[0] - accelNom[0]) * _aRes * 1000.0);
Serial.print("+Ay results:"); Serial.println((accelPTest[1] - accelNom[1]) * _aRes * 1000.0);
Serial.print("-Ay results:"); Serial.println((accelNTest[1] - accelNom[1]) * _aRes * 1000.0);
Serial.print("+Az results:"); Serial.println((accelPTest[2] - accelNom[2]) * _aRes * 1000.0);
Serial.print("-Az results:"); Serial.println((accelNTest[2] - accelNom[2]) * _aRes * 1000.0);
Serial.println("Should be between 90 and 1700 mg");
Serial.println("Gyro Self Test:");
Serial.print("+Gx results:"); Serial.print((gyroPTest[0] - gyroNom[0]) * _gRes); Serial.println(" dps");
Serial.print("-Gx results:"); Serial.println((gyroNTest[0] - gyroNom[0]) * _gRes);
Serial.print("+Gy results:"); Serial.println((gyroPTest[1] - gyroNom[1]) * _gRes);
Serial.print("-Gy results:"); Serial.println((gyroNTest[1] - gyroNom[1]) * _gRes);
Serial.print("+Gz results:"); Serial.println((gyroPTest[2] - gyroNom[2]) * _gRes);
Serial.print("-Gz results:"); Serial.println((gyroNTest[2] - gyroNom[2]) * _gRes);
Serial.println("Should be between 20 and 80 dps");
delay(2000);
}
void LSM6DSM::offsetBias(float * dest1, float * dest2)
{
int16_t temp[7] = {0, 0, 0, 0, 0, 0, 0};
int32_t sum[7] = {0, 0, 0, 0, 0, 0, 0};
Serial.println("Calculate accel and gyro offset biases: keep sensor flat and motionless!");
delay(4000);
for (int ii = 0; ii < 128; ii++)
{
readData(temp);
sum[1] += temp[1];
sum[2] += temp[2];
sum[3] += temp[3];
sum[4] += temp[4];
sum[5] += temp[5];
sum[6] += temp[6];
delay(50);
}
dest1[0] = sum[1]*_gRes/128.0f;
dest1[1] = sum[2]*_gRes/128.0f;
dest1[2] = sum[3]*_gRes/128.0f;
dest2[0] = sum[4]*_aRes/128.0f;
dest2[1] = sum[5]*_aRes/128.0f;
dest2[2] = sum[6]*_aRes/128.0f;
if(dest2[0] > 0.8f) {dest2[0] -= 1.0f;} // Remove gravity from the x-axis accelerometer bias calculation
if(dest2[0] < -0.8f) {dest2[0] += 1.0f;} // Remove gravity from the x-axis accelerometer bias calculation
if(dest2[1] > 0.8f) {dest2[1] -= 1.0f;} // Remove gravity from the y-axis accelerometer bias calculation
if(dest2[1] < -0.8f) {dest2[1] += 1.0f;} // Remove gravity from the y-axis accelerometer bias calculation
if(dest2[2] > 0.8f) {dest2[2] -= 1.0f;} // Remove gravity from the z-axis accelerometer bias calculation
if(dest2[2] < -0.8f) {dest2[2] += 1.0f;} // Remove gravity from the z-axis accelerometer bias calculation
}
void LSM6DSM::readData(int16_t * destination)
{
uint8_t rawData[14]; // x/y/z accel register data stored here
readBytes(LSM6DSM_ADDRESS, LSM6DSM_OUT_TEMP_L, 14, &rawData[0]); // Read the 14 raw data registers into data array
destination[0] = ((int16_t)rawData[1] << 8) | rawData[0] ; // Turn the MSB and LSB into a signed 16-bit value
destination[1] = ((int16_t)rawData[3] << 8) | rawData[2] ;
destination[2] = ((int16_t)rawData[5] << 8) | rawData[4] ;
destination[3] = ((int16_t)rawData[7] << 8) | rawData[6] ;
destination[4] = ((int16_t)rawData[9] << 8) | rawData[8] ;
destination[5] = ((int16_t)rawData[11] << 8) | rawData[10] ;
destination[6] = ((int16_t)rawData[13] << 8) | rawData[12] ;
}
// I2C scan function
void LSM6DSM::I2Cscan()
{
// scan for i2c devices
byte error, address;
int nDevices;
Serial.println("Scanning...");
nDevices = 0;
for(address = 1; address < 127; address++ )
{
// The i2c_scanner uses the return value of
// the Write.endTransmission to see if
// a device did acknowledge to the address.
// Wire.beginTransmission(address);
// error = Wire.endTransmission();
error = Wire.transfer(address, NULL, 0, NULL, 0);
if (error == 0)
{
Serial.print("I2C device found at address 0x");
if (address<16)
Serial.print("0");
Serial.print(address,HEX);
Serial.println(" !");
nDevices++;
}
else if (error==4)
{
Serial.print("Unknown error at address 0x");
if (address<16)
Serial.print("0");
Serial.println(address,HEX);
}
}
if (nDevices == 0)
Serial.println("No I2C devices found\n");
else
Serial.println("done\n");
}
// I2C read/write functions for the LSM6DSM
void LSM6DSM::writeByte(uint8_t address, uint8_t subAddress, uint8_t data) {
uint8_t temp[2];
temp[0] = subAddress;
temp[1] = data;
Wire.transfer(address, &temp[0], 2, NULL, 0);
}
uint8_t LSM6DSM::readByte(uint8_t address, uint8_t subAddress) {
uint8_t temp[1];
Wire.transfer(address, &subAddress, 1, &temp[0], 1);
return temp[0];
}
void LSM6DSM::readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest) {
Wire.transfer(address, &subAddress, 1, dest, count);
}