Keyestudio ESP32 Manual page 142

ESP32 Starter Kit
6. Knowledge Expansion
Let's make a rangefinder.
We display characters on LCD 1602. Program to show "Keyestudio" at (3,0) and "distance:" at (0,1) followed by the
distance value at (9,1).
When the value is smaller than 100(or 10), a residue of the third(or the second) bit still exists. Therefore, an "if"
judgement is necessary to determine a certain condition.
Wiring Diagram
Code
/*
keyestudio ESP32 Inventor Learning Kit
Project 25.2Ultrasonic Rangefinder
http://www.keyestudio.com
*/
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,16,2);
line display
int
distance = 0; //Define a variable to receive the diatance value
int
EchoPin = 14; //Connect Echo pin to io14
138
//set the LCD address to 0x27 for a 16 chars and 2␣
(continues on next page)
Chapter 8. Arduino Tutorial