L3G4200D three-axis gyroscope and ESP8266 example

In this example we connect a L3G4200D three-axis gyroscope module to a Wemos Mini – you can of course use any ESP8266 based board but this is what I tested out.

First lets look at some information about the sensor from the manufacturer

The L3G4200D is a low-power three-axis gyroscope providing three different user selectable full scales (±250/±500/±2000 dps).It includes a sensing element and an IC interface able to provide the detected angular rate to the external world through a digital interface (I2C/SPI).

The sensing element is manufactured using specialized micromachining processes, while the IC interface is realized using a CMOS technology that allows designing a dedicated circuit which is trimmed to better match the sensing element characteristics.

Features

  • Three selectable full scales (±250/500/2000 dps)
  • I2C/SPI digital output interface
  • 16 bit rate value data output
  • Two digital output lines (interrupt and dataready)
  • Integrated low and high pass filters with user selectable bandwidth
  • Embedded self-test
  • Wide supply voltage, 2.4 V to 3.6 V
  • Low voltage compatible IOs, 1.8 V
  • Embedded power-down and sleep mode
  • High shock survivability
  • Extended operating temperature range (-40 °C to +85 °C)

This was my sensor of choice that I used

Parts List

Here are the parts I used

 

Name Links
Wemos Mini
L3G4200D
Connecting cables

Schematic/Connection

 

ESP8266 and L3G4200D layout
ESP8266 and L3G4200D layout

 

Code Example

This example uses the library – https://github.com/jarzebski/Arduino-L3G4200D

This is one of the default examples when you install the library above, there are quite a few to browse

/*
    L3G4200D Triple Axis Gyroscope. Simple Example.
    GIT: https://github.com/jarzebski/Arduino-L3G4200D
    Web: http://www.jarzebski.pl
    (c) 2014 by Korneliusz Jarzebski
*/

#include <Wire.h>
#include <L3G4200D.h>

L3G4200D gyroscope;

void setup() 
{
  Serial.begin(9600);
  Serial.println("Initialize L3G4200D");

  while(!gyroscope.begin(L3G4200D_SCALE_2000DPS, L3G4200D_DATARATE_400HZ_50))
  {
    Serial.println("Could not find a valid L3G4200D sensor, check wiring!");
    delay(500);
  }

  // Check selected scale
  Serial.print("Selected scale: ");

  switch(gyroscope.getScale())
  {
    case L3G4200D_SCALE_250DPS:
      Serial.println("250 dps");
      break;
    case L3G4200D_SCALE_500DPS:
      Serial.println("500 dps");
      break;
    case L3G4200D_SCALE_2000DPS:
      Serial.println("2000 dps");
      break;
    default:
      Serial.println("unknown");
      break;
  }

  // Check Output Data Rate and Bandwidth
  Serial.print("Output Data Rate: ");

  switch(gyroscope.getOdrBw())
  {
    case L3G4200D_DATARATE_800HZ_110:
      Serial.println("800HZ, Cut-off 110");
      break;
    case L3G4200D_DATARATE_800HZ_50:
      Serial.println("800HZ, Cut-off 50");
      break;
    case L3G4200D_DATARATE_800HZ_35:
      Serial.println("800HZ, Cut-off 35");
      break;
    case L3G4200D_DATARATE_800HZ_30:
      Serial.println("800HZ, Cut-off 30");
      break;
    case L3G4200D_DATARATE_400HZ_110:
      Serial.println("400HZ, Cut-off 110");
      break;
    case L3G4200D_DATARATE_400HZ_50:
      Serial.println("400HZ, Cut-off 50");
      break;
    case L3G4200D_DATARATE_400HZ_25:
      Serial.println("400HZ, Cut-off 25");
      break;
    case L3G4200D_DATARATE_400HZ_20:
      Serial.println("400HZ, Cut-off 20");
      break;
    case L3G4200D_DATARATE_200HZ_70:
      Serial.println("200HZ, Cut-off 70");
      break;
    case L3G4200D_DATARATE_200HZ_50:
      Serial.println("200HZ, Cut-off 50");
      break;
    case L3G4200D_DATARATE_200HZ_25:
      Serial.println("200HZ, Cut-off 25");
      break;
    case L3G4200D_DATARATE_200HZ_12_5:
      Serial.println("200HZ, Cut-off 12.5");
      break;
    case L3G4200D_DATARATE_100HZ_25:
      Serial.println("100HZ, Cut-off 25");
      break;
    case L3G4200D_DATARATE_100HZ_12_5:
      Serial.println("100HZ, Cut-off 12.5");
      break;
    default:
      Serial.println("unknown");
      break;
  }

  // Calibrate gyroscope. The calibration must be at rest.
  // If you don't want calibrate, comment this line.
  gyroscope.calibrate();

  // Set threshold sensivty. Default 3.
  // If you don't want use threshold, comment this line or set 0.
  gyroscope.setThreshold(3);
}

void loop()
{
  // Read normalized values
  Vector raw = gyroscope.readRaw();

  // Read normalized values in deg/sec
  Vector norm = gyroscope.readNormalize();

  // Output raw
  Serial.print(" Xraw = ");
  Serial.print(raw.XAxis);
  Serial.print(" Yraw = ");
  Serial.print(raw.XAxis);
  Serial.print(" Zraw = ");
  Serial.print(raw.YAxis);

  // Output normalized
  Serial.print(" Xnorm = ");
  Serial.print(norm.XAxis);
  Serial.print(" Ynorm = ");
  Serial.print(norm.YAxis);
  Serial.print(" ZNorm = ");
  Serial.print(norm.ZAxis);

  Serial.println();
}

 

Output

Here is what I saw in Serial monitor, l moved the module around to see different values

Xraw = 42.00 Yraw = 42.00 Zraw = 65514.00 Xnorm = 0.00 Ynorm = 0.00 ZNorm = 0.00
Xraw = 45.00 Yraw = 45.00 Zraw = 65518.00 Xnorm = 0.00 Ynorm = 0.00 ZNorm = 0.00
Xraw = 111.00 Yraw = 111.00 Zraw = 65201.00 Xnorm = 0.00 Ynorm = 0.00 ZNorm = 0.00
Xraw = 1927.00 Yraw = 1927.00 Zraw = 65474.00 Xnorm = 0.00 Ynorm = 0.00 ZNorm = 0.00
Xraw = 1051.00 Yraw = 1051.00 Zraw = 65236.00 Xnorm = 0.00 Ynorm = 0.00 ZNorm = 0.00
Xraw = 878.00 Yraw = 878.00 Zraw = 790.00 Xnorm = 0.00 Ynorm = 0.00 ZNorm = 0.00
Xraw = 63084.00 Yraw = 63084.00 Zraw = 954.00 Xnorm = 0.00 Ynorm = 0.00 ZNorm = 0.00
Xraw = 262.00 Yraw = 262.00 Zraw = 2630.00 Xnorm = 0.00 Ynorm = 0.00 ZNorm = 0.00
Xraw = 65220.00 Yraw = 65220.00 Zraw = 62634.00 Xnorm = 0.00 Ynorm = 0.00 ZNorm = 0.00
Xraw = 65155.00 Yraw = 65155.00 Zraw = 133.00 Xnorm = 0.00 Ynorm = 0.00 ZNorm = 0.00
Xraw = 65102.00 Yraw = 65102.00 Zraw = 505.00 Xnorm = 0.00 Ynorm = 0.00 ZNorm = 0.00

 

Links

 

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