Ian Cumming
Published © GPL3+

A Simple Arduino Menu With An LCD

I've created a simple menu with an LCD that controls what an LED does. The menu is easy to edit and adapt for various projects.

IntermediateProtip1 hour30,478
A Simple Arduino Menu With An LCD

Things used in this project

Story

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Schematics

Schematics for the LCD Menu

Menu schematic ukba8t7r7x

LCD Menu Breadboard

Menu breadboard yudrzqr7uu

Code

Simple LCD menu

Arduino
The Arduino IDE code to run the Arduino Uno
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2); // ARDUINO UNO
//LiquidCrystal lcd(3, 2, 1, 7, 8, 9, 10); // ATTINY84
byte buttons[] = {6,7,8}; //10 for additional pin
const byte nrButtons = 3; // change to 4 if additional button added
int menusize = 10;
String menu[] = {
  "Menu",                   //0
  "Menu>LED",               //1
  "Menu>LED>Off",           //2
  "Menu>LED>On",            //3
  "Menu>LED>Fade",          //4
  "Menu>LED>Blink",         //5
  "Menu>LCDlight",          //6
  "Menu>Nothing1",          //7  
  "Menu>Nothing2",          //8
  "Menu>Nothing3"           //9
};

int t;
byte pressedButton, currentPos,currentPosParent, possiblePos[20], possiblePosCount, possiblePosScroll = 0;
String parent = "";

int brightness;
int LCDtoggle = 0;
int fadeAmount = 5;
unsigned long timer = (millis() / 10);
int ledMode = 0;

void updateMenu () {
  possiblePosCount = 0;
  while (possiblePosCount == 0) {
    
    for (t = 1; t < menusize;t++) {
      if (mid(menu[t],1,inStrRev(menu[t],">")-1).equals(menu[currentPos])) {
        possiblePos[possiblePosCount]  =  t;
        possiblePosCount = possiblePosCount + 1;
      }
    }
    
    //find the current parent for the current menu
    parent = mid(menu[currentPos],1,inStrRev(menu[currentPos],">")-1);
    currentPosParent = 0;
    for (t = 0; t < menusize; t++) {
       if (parent == menu[t]) {currentPosParent = t;}
    }

    // reached the end of the Menu line
    if (possiblePosCount == 0) {
      //Menu Option Items
      switch (currentPos) {
        case 2:
        case 3:
        case 4:
        case 5://Choose between 2,3,4,5
          for (t = 2; t<6; t++) {
            if (mid(menu[t],len(menu[t]),1) == "*") {
              menu[t] = mid(menu[t],1,len(menu[t])-1);
            }
          }
          menu[currentPos] = menu[currentPos] + "*";
        break;
        case 6: //Toggle
          if (mid(menu[currentPos],len(menu[currentPos]),1) == "*") {
            menu[currentPos] = mid(menu[currentPos],1,len(menu[currentPos])-1);
          } else {
            menu[currentPos] = menu[currentPos] + "*";    
          }
          
        break;
      }

      //Set Variables
      switch (currentPos) {
        case 2:
          ledMode = 0;
        break;
        case 3:
          ledMode = 1;
        break;
        case 4:
          brightness = 128;
          ledMode = 2;
        break;
        case 5:
          brightness = 0;
          ledMode = 3;
        break;
        case 6:
          LCDtoggle = abs(LCDtoggle - 1);
          digitalWrite(13,LCDtoggle);
        break;
      }


      // go to the parent
      currentPos = currentPosParent;
    }
  }
    lcd.clear();
    lcd.setCursor(0,0); lcd.print(mid(menu[currentPos],inStrRev(menu[currentPos],">")+1,len(menu[currentPos])-inStrRev(menu[currentPos],">")));
    lcd.setCursor(0,1); lcd.print(mid(menu[possiblePos[possiblePosScroll]],inStrRev(menu[possiblePos[possiblePosScroll]],">")+1,len(menu[possiblePos[possiblePosScroll]])-inStrRev(menu[possiblePos[possiblePosScroll]],">")));

}

// Look for a button press
byte checkButtonPress() {
  byte bP = 0;
  byte rBp = 0;
  for (t = 0; t<nrButtons;t++) {
    if (digitalRead(buttons[t]) == 0) {bP = (t + 1);}
  }
  rBp = bP;
  while (bP != 0) { // wait while the button is still down
    bP = 0;
    for (t = 0; t<nrButtons;t++) {
      if (digitalRead(buttons[t]) == 0) {bP = (t + 1);}
    }
  }
  return rBp;
}



void setup() {
  
  lcd.begin(16,2); 
  lcd.clear();
  
  for (t=0;t<nrButtons;t++) {
    pinMode(buttons[t],INPUT_PULLUP); 
  }
  
  pinMode(13,OUTPUT);
  pinMode(9,OUTPUT);

  lcd.setCursor(0,0); lcd.print("HELLO");
  delay(1000);
  updateMenu();

}

void loop() {

  
  switch (ledMode) {
    case 0:
      analogWrite(9, 0);
    break;
    case 1:
      analogWrite(9, 255);
    break;
    case 3:
      if ((millis() / 10) - timer > 30) {
        timer = (millis() / 10);
        brightness = abs(brightness - 255);
        timer = (millis() / 10);
        analogWrite(9, brightness);
      }
    break;
    case 2:
      if ((millis() / 10) - timer > 3) {
        timer = (millis() / 10);
        analogWrite(9, brightness);
        brightness = brightness + fadeAmount;
        if (brightness <= 0 || brightness >= 255) {
          fadeAmount = -fadeAmount;
        }
      }
    break;
  }

  pressedButton = checkButtonPress();
  if (pressedButton !=0) {
    switch (pressedButton) {
      case 1:
          possiblePosScroll = (possiblePosScroll + 1) % possiblePosCount; // Scroll
      break;
      // If I wanted a 4 button controll of the menu
      //case 4:
        //  possiblePosScroll = (possiblePosScroll + possiblePosCount - 1) % possiblePosCount; // Scroll
      //break;
      case 2:
        currentPos = possiblePos[possiblePosScroll]; //Okay
      break;
      case 3:
        currentPos = currentPosParent; //Back
        possiblePosScroll = 0;
      break;
    }
    updateMenu();
  }
}

functions

Arduino
Supporting Functions
String mid(String str, int start, int len) {
   int t = 0;
   String u = ""; 
   for (t = 0; t < len;t++) {
    u = u + str.charAt(t+start-1);
   }
   return u;
}

int inStrRev(String str,String chr) {
  int t = str.length()-1;
  int u = 0;
   while (t>-1) {
    if (str.charAt(t)==chr.charAt(0)) {
      u = t+1;t = -1;
    }
    t = t - 1;
   }
  return u;
}

int len(String str) {
  return str.length();
}

Credits

Ian Cumming

Ian Cumming

6 projects • 31 followers
I like stuff, from building rockets to elctronics.

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