Option menus with arduino and LCD screen

Projects Programming
1

I am using an arduino for an automation project, and as part of the project, it will also give the option to use an LCD screen which accepts button inputs to allow me to set specific numeric options. More specifically, it'll allow me to specify how much heat a heating band I have attached to the circuit will output. My issue as of now is that my option choices won't show on the LCD.

Here is the LCD I'm using for this project https://cdn-learn.adafruit.com/downloads/pdf/rgb-lcd-shield.pdf

Also, I'm using the Arduino Mega.

#include <string.h>
#include <SoftwareSerial.h>
#include <avr/pgmspace.h>
#include <Adafruit_RGBLCDShield.h>
#include <utility/Adafruit_MCP23017.h>
#include <Wire.h>

// The shield uses the I2C SCL and SDA pins. On classic Arduinos
// this is Analog 4 and 5 so you can't use those for analogRead() anymore
// However, you can connect other I2C sensors to the I2C bus and share
// the I2C bus.
Adafruit_RGBLCDShield lcd = Adafruit_RGBLCDShield();

// These #defines make it easy to set the backlight color
#define RED 0x1
#define YELLOW 0x3
#define GREEN 0x2
#define TEAL 0x6
#define BLUE 0x4
#define VIOLET 0x5
#define WHITE 0x7
int letter = 0;
int line = 0;
int myvals [] = {70, 80, 90,100,110};

void setup() {
  // Debugging output
  Serial.begin(9600);
  // set up the LCD's number of columns and rows: 
  lcd.begin(16, 2);

  // Print a message to the LCD.
  int time = millis();
  lcd.print("LAZY GARDENER!");
  time = millis() - time;
  Serial.print("Took "); Serial.print(time); Serial.println(" ms");
  lcd.setBacklight(WHITE);
}

uint8_t i=0;

void loop() {
  // set the cursor to column 0, line 1
  // (note: line 1 is the second row, since counting begins with 0):
  lcd.setCursor(0, 1);
  // print the number of seconds since reset:
  lcd.print(millis()/1000);

  uint8_t buttons = lcd.readButtons();

  if (buttons) {
    lcd.clear();
    lcd.setCursor(0,0);
    if (buttons & BUTTON_UP) {
      lcd.print("Choosing Temperature ");
      lcd.setBacklight(RED);
      lcd.setCursor(letter, line + 1);
    }
    
    if (buttons & BUTTON_DOWN) {
      lcd.print("DOWN ");
      lcd.setBacklight(YELLOW);
    }
    if (buttons & BUTTON_LEFT) {
      lcd.print("LEFT ");
      lcd.setBacklight(GREEN);
    }
    if (buttons & BUTTON_RIGHT) {
      lcd.print("RIGHT ");
      lcd.setBacklight(TEAL);
    }
    if (buttons & BUTTON_SELECT) {
      lcd.print("SELECT ");
      lcd.setBacklight(VIOLET);
    }
  }
}
2 
  int time = millis();

The millis() function does not return an int.

What do your Serial.print() statements tell you is happening?

3

PaulS:

  int time = millis();

The millis() function does not return an int.

What do your Serial.print() statements tell you is happening?

That piece of code there is showing a count for how long the screen has been active and displays "The Lazy Gardener". It also displays on the screen the "Choosing Temp" when they "Up Button" is pushed. From there it should allow me to scroll through temperature options.