[arduino] Grower with lcd menu, temp/moisture sensors - under dev

grower.ino

/*
 Temperature and moisture sensors displayed at 16x9 lcd. 
 Menu navigation using 2-axis joystick.

  The circuit:
 * LCD RS pin to digital pin 6
 * LCD Enable pin to digital pin 7
 * LCD D4 pin to digital pin 5
 * LCD D5 pin to digital pin 4
 * LCD D6 pin to digital pin 3
 * LCD D7 pin to digital pin 2
 * LCD R/W pin to ground
 * LCD VSS pin to ground
 * LCD VCC pin to 5V
 * 10K resistor:
 * ends to +5V and ground
 * wiper to LCD VO pin (pin 3)
 
  Joystick ---> Arduino:
 * GND          GND
 * +5V          5V
 * VRx          A0
 * VRy          A1 
 * SW           9

  Sensors:
 * Temperature A2
 * Moisture    A3

 by Diego Gobbi Slomp

 Based on this examples:
 * http://www.arduino.cc/en/Tutorial/LiquidCrystalHelloWorld
 * https://www.addicore.com/v/vspfiles/downloadables/Product%20Downloadables/Project_Interface_Kit/Joystick_2Axis_with_Switch.txt
*/

// include the library code:
#include <LiquidCrystal.h>

//Arduino pins attached to joystick 
#define joystick_switch_pin  9
#define joystick_x_pin       A0
#define joystick_y_pin       A1

//Temp sensor
#define temperature_sensor_pin A2

//Moisture sensor
#define moisture_sensor_pin A3

//Joystick values
#define up    0
#define right 1
#define down  2
#define left  3
#define enter 4
#define none  5

// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 6, en = 7, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

// Menus
// TODO: Submenus
String main_menu[] = {"1.Temperature:","2.Moisture:","3.Lights:"};

// Vars to display in lcd
int current_menu_item;

String *current_menu;
// Used to check joystick state
int last_joy_read;

float read_temperature() {
	float temperatureValue = analogRead(temperature_sensor_pin);
	temperatureValue = (5.0 * analogRead(temperature_sensor_pin) * 100.0) / 1024;	// TODO: check float int cast
	return temperatureValue;
}

int read_moisture() {
 	int moistureValue = analogRead(moisture_sensor_pin); // TODO: check moisture value before return
	return moistureValue;
}

void check_sensors() {
	float temperature = read_temperature();
	int moisture = read_moisture();	
	main_menu[0] = "1. Temp: " + String(temperature) + "C";
	main_menu[1] = "2. Moist: " + String(moisture);
}

int read_joystick() {
  int output = none;
  // read all joystick values
  int X_Axis = analogRead(joystick_x_pin);     // read the x axis value
  int Y_Axis = analogRead(joystick_y_pin);     // read the y axis value
  Y_Axis = map(Y_Axis, 0, 1023, 1023, 0);      // invert the input from the y axis so that pressing the stick forward gives larger values
  int SwitchValue = digitalRead(joystick_switch_pin);  // read the state of the switch
  SwitchValue = map(SwitchValue, 0, 1, 1, 0);  // invert the input from the switch to be high when pressed
  
  if (SwitchValue == 1){
    output = enter;
  } else if (X_Axis >= 900) {
    output = right;
  } else if (X_Axis <= 100) {
    output = left;
  } else if (Y_Axis >= 900) {
    output = up;
  } else if (Y_Axis <= 100) {
    output = down;
  }
  return output;
}

void print_line(int line, String text) {
    lcd.setCursor(0, line);
    lcd.print("               ");
    lcd.setCursor(0, line);
    lcd.print(text);
}

void move_up(){
  if (current_menu_item <= 0){
    current_menu_item = sizeof(current_menu);
  } else {
    current_menu_item--;
  }  
}

void move_down(){
  if (current_menu_item >= sizeof(current_menu)){
    current_menu_item = 0;
  } else {
    current_menu_item++;
  }
}

void move_right(){
  // TODO: enter submenu
  // TODO: change selected value
  // TODO: increase selected value (ex: defaut temperature, timers, etc..)
}
void move_left(){
  // TODO: go back mainmenu
  // TODO: go back submenu
  // TODO: decrease selected value (ex: defaut temperature, timers, etc..)
}

void setup() {
  // arduino default once time function
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);

  // set up joy pins
  pinMode(joystick_switch_pin, INPUT_PULLUP);
  
  // Print template on lcd.
  check_sensors();
  print_line(0, "Main Menu:");
  print_line(1, main_menu[current_menu_item]);
  
  // Init vars
  current_menu_item = 0;
  last_joy_read = none;
  current_menu = main_menu;
}

void loop() {
  // "main" arduino program
  check_sensors();
  int current_joy_read = read_joystick();

  if (current_joy_read != last_joy_read) {
    last_joy_read = current_joy_read;
    
    switch (current_joy_read) {
      case up:
        move_up();
        break;
      case down:
        move_down();
        break;
      case right:
        move_right();
        break;
      case left:
        move_left();
        break;
      default: break;
    }
    delay(100);   
  } 
  // clear line and print values to lcd
  print_line(1, current_menu[current_menu_item]);
  delay(100);   
}