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3 Axis Gyro-L3G4200D

Introduction

The L3G4200D is a low-power three-axis angular rate sensor, it contains a sensing element and an IC interface in order to providing the resolute to the external controller through a digital interface, there are two kinds of transform type: I2C and SPI.

Technical data

Supply voltage: 2.4 to 3.6V

Low voltage-compatible IOs (1.8V)

Embedded power-down and sleep mode

Embedded temperature sensor


Features

8-bit temperature data output

16 bit-rate value data output

I2C/SPI digital output interface

Two digital output lines(interrupt and data ready)

Integrated low and high pass filters with user selectable bandwidth

 

Usage

#include <SPI.h>

#include "L3G4200D.h"

 

// pin definitions

const int int2pin = 6;

const int int1pin = 7;

const int chipSelect = 10;

 

// gyro readings

int x, y, z;

 

void setup()

{

  Serial.begin(9600);

  

  // Start the SPI library:

  SPI.begin();

  SPI.setDataMode(SPI_MODE3);

  SPI.setClockDivider(SPI_CLOCK_DIV8);

  

  pinMode(int1pin, INPUT);

  pinMode(int2pin, INPUT);

  pinMode(chipSelect, OUTPUT);

  digitalWrite(chipSelect, HIGH);

  delay(100);

  

  setupL3G4200D(2);  // Configure L3G4200 with selectabe full scale range

  // 0: 250 dps

  // 1: 500 dps

  // 2: 2000 dps

}

 

void loop()

{

  // Don't read gyro values until the gyro says it's ready

  while(!digitalRead(int2pin))

    ;  

  getGyroValues();  // This will update x, y, and z with new values

  

  Serial.print(x, DEC);

  Serial.print("\t");

  Serial.print(y, DEC);

  Serial.print("\t");

  Serial.print(z, DEC);

  Serial.print("\t");

  Serial.println();

  

  //delay(100); // may want to stick this in for readability

}

 

int readRegister(byte address)

{

  int toRead;

  

  address |= 0x80;  // This tells the L3G4200D we're reading;

  

  digitalWrite(chipSelect, LOW);

  SPI.transfer(address);

  toRead = SPI.transfer(0x00);

  digitalWrite(chipSelect, HIGH);

  

  return toRead;

}

 

void writeRegister(byte address, byte data)

{

  address &= 0x7F;  // This to tell the L3G4200D we're writing

  

  digitalWrite(chipSelect, LOW);

  SPI.transfer(address);

  SPI.transfer(data);

  digitalWrite(chipSelect, HIGH);

}

 

int setupL3G4200D(byte fullScale)

{

  // Let's first check that we're communicating properly

  // The WHO_AM_I register should read 0xD3

  if(readRegister(WHO_AM_I)!=0xD3)

    return -1;

    

  // Enable x, y, z and turn off power down:

  writeRegister(CTRL_REG1, 0b00001111);

  

  // If you'd like to adjust/use the HPF, you can edit the line below to configure CTRL_REG2:

  writeRegister(CTRL_REG2, 0b00000000);

  

  // Configure CTRL_REG3 to generate data ready interrupt on INT2

  // No interrupts used on INT1, if you'd like to configure INT1

  // or INT2 otherwise, consult the datasheet:

  writeRegister(CTRL_REG3, 0b00001000);

  

  // CTRL_REG4 controls the full-scale range, among other things:

  fullScale &= 0x03;

  writeRegister(CTRL_REG4, fullScale<<4);

  

  // CTRL_REG5 controls high-pass filtering of outputs, use it

  // if you'd like:

  writeRegister(CTRL_REG5, 0b00000000);

}

 

void getGyroValues()

{

  x = (readRegister(0x29)&0xFF)<<8;

  x |= (readRegister(0x28)&0xFF);

  

  y = (readRegister(0x2B)&0xFF)<<8;

  y |= (readRegister(0x2A)&0xFF);

  

  z = (readRegister(0x2D)&0xFF)<<8;

  z |= (readRegister(0x2C)&0xFF);

}


Resource

Program

Schematic

Datesheet

 


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