cheat-calc - Wokwi ESP32, STM32, Arduino Simulator

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include <WebServer.h>
#include <Keypad.h>

// LCD setup
LiquidCrystal_I2C lcd(0x27, 20, 4); // Adjust the address and size as needed

// Wi-Fi setup
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// Web server
WebServer server(80);

// Keypad setup
const byte ROWS = 4; // four rows
const byte COLS = 4; // four columns
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {19, 18, 5, 17}; // Connect to the row pinouts of the keypad
byte colPins[COLS] = {16, 4, 0, 2}; // Connect to the column pinouts of the keypad

Keypad keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

String inputData = "";
unsigned long lastPressTime = 0;
int pressCount = 0;
char lastKey = '\0';

void setup() {
  // Initialize serial communication
  Serial.begin(115200);

  // Initialize LCD
  lcd.begin(20, 4);
  lcd.backlight();
  lcd.print("WiFi AP Started");

  // Start Wi-Fi Access Point
  WiFi.softAP(ssid, password);
  Serial.println("Access Point Started");
  Serial.print("IP Address: ");
  Serial.println(WiFi.softAPIP());

  // Setup web server routes
  server.on("/", HTTP_GET, handleRoot);
  server.on("/send", HTTP_POST, handleSend);
  server.begin();
}

void loop() {
  server.handleClient();

  // Check for keypad input
  char key = keypad.getKey();
  if (key) {
    unsigned long currentTime = millis();
    
    // Check if the same key is pressed again within 300 ms
    if (key == lastKey && (currentTime - lastPressTime < 300)) {
      pressCount++;
    } else {
      pressCount = 1; // Reset count for a new key press
    }
    
    lastPressTime = currentTime;
    lastKey = key;

    // Process the key press based on the count
    char character = getCharacter(key, pressCount);
    if (character != '\0') {
      inputData += character; // Append the selected character to inputData
      lcd.clear();
      lcd.print("Input: " + inputData);
    }
  }
}

char getCharacter(char key, int count) {
  switch (key) {
    case '1':
      return (count == 1) ? 'A' : (count == 2) ? 'B' : (count == 3) ? 'C' : '\0';
    case '2':
      return (count == 1) ? 'D' : (count == 2) ? 'E' : (count == 3) ? 'F' : '\0';
    case '3':
      return (count == 1) ? 'G' : (count == 2) ? 'H' : (count == 3) ? 'I' : '\0';
    case '4':
      return (count == 1) ? 'J' : (count == 2) ? 'K' : (count == 3) ? 'L' : '\0';
    case '5':
      return (count == 1) ? 'M' : (count == 2) ? 'N' : (count == 3) ? 'O' : '\0';
    case '6':
      return (count == 1) ? 'P' : (count == 2) ? 'Q' : (count == 3) ? 'R' : (count == 4) ? 'S' : '\0';
    case '7':
      return (count == 1) ? 'T' : (count == 2) ? 'U' : (count == 3) ? 'V' : '\0';
    case '8':
      return (count == 1) ? 'W' : (count == 2) ? 'X' : (count == 3) ? 'Y' : (count == 4) ? 'Z' : '\0';
    case '9':
      return ' '; // Space for key '9'
    default:
      return '\0'; // No valid character
  }
}

void handleRoot() {
  String html = "<html><body><h1>ESP32 Keypad Input</h1>";
  html += "<form action=\"/send\" method=\"POST\">";
  html += "<input type=\"text\" name=\"inputData\" value=\"" + inputData + "\"><br>";
  html += "<input type=\"submit\" value=\"Send\">";
  html += "</form></body></html>";
  server.send(200, "text/html", html);
}

void handleSend() {
  // Handle the input data sent from the form
  String inputDataReceived = server.arg("inputData");
  Serial.println("Received Input: " + inputDataReceived);
  server.send(200, "text/plain", "Input received: " + inputDataReceived);
}