ESP32, Sensor

Interface LSM9DS1 9DOF IMU With TTGO T-Display ESP32

by Idris
December 3, 2019

ESP32, LSM9DS1, TTGO

Getting Started With TTGO T-Display ESP32.

Introduction

TTGO T-Display ESP32 is a tiny microcontroller board. It comes with 1.14″ LCD, 2 programmable push button, battery connector with a charging circuit. Since it uses ESP32 module, so it has WiFi and Bluetooth capability. Plus, the price is affordable. Yes, I love it. In this tutorial, I will share how to get started with this board and interface LSM9DS1 9DOF IMU sensor module.

Video

This video shows how to get started with TTGO T-Display ESP32 and interface LSM9DS1 9DOF IMU sensor module.

Hardware Preparation

This is the list of items used in the video.

TTGO T-Display ESP32 1.14 Display Module

LSM9DS1 9DOF Accel/Mag/Gyro/Temp Sensor Module

USB C to Type A Cable (1 Meter)

Jumper Wire

Adjustable 60W Soldering Iron (EU Plug)

Wiring connection table.

TTGO T-Display ESP32	LSM9DS1 9DOF IMU
3.3V	VDD
GND	GND
21	SDA
22	SCL

Sample Program

This is Arduino sample program to read LSM9DS1 data and display to LCD. It requires 2 additional library from Arduino Library Manager:

TFT_eSPI by Bodmer Version 1.4.16.
Adafruit LSM9DS1 Library by Adafruit Version 1.0.1

    /* 
   Tutorial: Interface LSM9DS1 with TTGO T-Display ESP32 
   Board: ESP32 Dev Module (TTGO LCD) 
   Ext libraries: 
   – TFT_eSPI by Bodmer Version 1.4.16 
   – Adafruit LSM9DS1 Library by Adafruit Version 1.0.1 
   */ 
    
  #include <SPI.h> 
  #include <TFT_eSPI.h> 
  TFT_eSPI tft = TFT_eSPI(); // Resolution 135 x 240 
  #define FF17 &FreeSans9pt7b 
  #define FF21 &FreeSansBold9pt7b 
  #define ROW1 0,16 
  #define ROW2 0,38 
  #define ROW3 0,60 
  #define ROW4 0,82 
  #define ROW5 0,104 
  #define ROW6 0,126 
    
  #include <Wire.h> 
  #include <Adafruit_LSM9DS1.h> 
  #include <Adafruit_Sensor.h> 
  Adafruit_LSM9DS1 lsm9ds1 = Adafruit_LSM9DS1(); 
    
  #define BUTTON1 35 
  #define BUTTON2 0 
    
  long previousMillis = 0; 
  int interval = 200; 
    
  float accX, accY, accZ; 
  float gyroX, gyroY, gyroZ; 
  float magnetX, magnetY, magnetZ; 
    
  boolean button1Pressed = false; 
  boolean button2Pressed = false; 
  int fontColor = 1; 
    
  void setup() 
  { 
   pinMode(BUTTON1, INPUT_PULLUP); 
   pinMode(BUTTON2, INPUT_PULLUP); 
    
   Serial.begin(115200); 
   Serial.println(F("Start")); 
    
   tft.init(); 
   tft.setRotation(3); // Change 1 or 3 for display orientation 
   tft.fillScreen(TFT_BLACK); 
    
   tft.setFreeFont(FF21); 
   tft.setTextColor(TFT_RED); 
   tft.setCursor(ROW1); 
   tft.print("LSM9DS1 Reading"); 
   tft.setTextColor(TFT_WHITE); 
   tft.setCursor(ROW2); 
   tft.print("—————————————"); 
   tft.setTextColor(TFT_BLUE); 
   tft.setCursor(ROW3); 
   tft.print("A:"); 
   tft.setCursor(ROW4); 
   tft.print("M:"); 
   tft.setCursor(ROW5); 
   tft.print("G:"); 
   tft.setTextColor(TFT_WHITE); 
   tft.setCursor(ROW6); 
   tft.print("—————————————"); 
   tft.setFreeFont(FF17); 
    
   if (!lsm9ds1.begin()) { 
   Serial.println(F("Oops… Unable to initialize the LSM9DS1. Check your wiring!")); 
   while (1); 
   } 
   Serial.println(F("Found LSM9DS1 9DOF")); 
    
   lsm9ds1.setupAccel(lsm9ds1.LSM9DS1_ACCELRANGE_2G); // Set the accelerometer range 
   lsm9ds1.setupMag(lsm9ds1.LSM9DS1_MAGGAIN_4GAUSS); // Set the magnetometer sensitivity 
   lsm9ds1.setupGyro(lsm9ds1.LSM9DS1_GYROSCALE_245DPS); // Setup the gyroscope 
  } 
    
  void loop() 
  { 
   if (millis() – previousMillis > interval) { 
   lsm9ds1.read(); 
    
   sensors_event_t a, m, g, temp; 
   lsm9ds1.getEvent(&a, &m, &g, &temp);  
    
   accX = a.acceleration.x; 
   accY = a.acceleration.y; 
   accZ = a.acceleration.z; 
   magnetX = m.magnetic.x; 
   magnetY = m.magnetic.y; 
   magnetZ = m.magnetic.z; 
   gyroX = g.gyro.x; 
   gyroY = g.gyro.y; 
   gyroZ = g.gyro.z; 
    
   Serial.print(F("Accel X: ")); Serial.print(accX); Serial.print(F(" m/s^2")); 
   Serial.print(F("\tY: ")); Serial.print(accY); Serial.print(F(" m/s^2")); 
   Serial.print(F("\tZ: ")); Serial.print(accZ); Serial.print(F(" m/s^2")); 
    
   Serial.print("Mag X: "); Serial.print(magnetX); Serial.print(F(" gauss")); 
   Serial.print("\tY: "); Serial.print(magnetY); Serial.print(F(" gauss")); 
   Serial.print("\tZ: "); Serial.print(magnetZ); Serial.println(F(" gauss")); 
    
   Serial.print("Gyro X: "); Serial.print(gyroX); Serial.print(F(" dps")); 
   Serial.print("\tY: "); Serial.print(gyroY); Serial.print(F(" dps")); 
   Serial.print("\tZ: "); Serial.print(gyroZ); Serial.println(F(" dps")); 
    
   Serial.println(); 
    
   tft.fillRect(40, 40, 200, 80, TFT_BLACK); 
   if (fontColor == 1) { 
   tft.setTextColor(TFT_GREEN); 
   } 
   else if (fontColor == 2) { 
   tft.setTextColor(TFT_YELLOW); 
   } 
   else if (fontColor == 3) { 
   tft.setTextColor(TFT_MAGENTA); 
   } 
   else if (fontColor == 4) { 
   tft.setTextColor(TFT_PURPLE); 
   } 
   else if (fontColor == 5) { 
   tft.setTextColor(TFT_CYAN); 
   } 
   else if (fontColor == 6) { 
   tft.setTextColor(TFT_ORANGE); 
   } 
   else if (fontColor == 7) { 
   tft.setTextColor(TFT_OLIVE); 
   } 
    
   tft.setCursor(40, 60); 
   tft.print(accX); tft.print("x "); 
   tft.print(accY); tft.print("y "); 
   tft.print(accZ); tft.print("z"); 
    
   tft.setCursor(40, 82); 
   tft.print(magnetX); tft.print("x "); 
   tft.print(magnetY); tft.print("y "); 
   tft.print(magnetZ); tft.print("z"); 
    
   tft.setCursor(40, 104); 
   tft.print(gyroX); tft.print("x "); 
   tft.print(gyroY); tft.print("y "); 
   tft.print(gyroZ); tft.print("z"); 
    
   previousMillis = millis(); 
   } 
    
   if (digitalRead(BUTTON1) == LOW && 
   button1Pressed == false) { 
   button1Pressed = true; 
    
   fontColor++; 
   if (fontColor > 7) { 
   fontColor = 1; 
   } 
   } 
   else if (digitalRead(BUTTON1) == HIGH && 
   button1Pressed == true) { 
   button1Pressed = false; 
   } 
    
   if (digitalRead(BUTTON2) == LOW && 
   button2Pressed == false) { 
   button2Pressed = true; 
    
   fontColor–; 
   if (fontColor < 1) { 
   fontColor = 7; 
   } 
   } 
   else if (digitalRead(BUTTON2) == HIGH && 
   button2Pressed == true) { 
   button2Pressed = false; 
   } 
  } 