Moving cursor on LCD and changing highlighted value

Question

I have the code shown below. The goal is to change the value of hours, minutes or seconds based on where the cursor is placed.

#include <Adafruit_RGBLCDShield.h>
#include <utility/Adafruit_MCP23017.h>
Adafruit_RGBLCDShield lcd = Adafruit_RGBLCDShield();

void setup() {
  lcd.begin(16, 2); //format of display
}

void loop() {
    int hours = 11;
    int minutes = 11;
    int seconds = 11;
    lcd.setCursor(0,0);
    lcd.print(hours);
    lcd.print(":");
    lcd.print(minutes);
    lcd.print(":");
    lcd.print(seconds);
    lcd.noBlink();
    delay(300);
    lcd.blink();
    delay(300);

    if (buttons & BUTTON_RIGHT) {
      move cursor right;
      if(lcd.setCursor == lcd.setCursor(0,3) { 
        minutes += 1 }

}

I though of a way to do this. I would have three variables and print each of these out with a default value. With the use of the buttons, the user should be able to move the blinking cursor to hours, minutes or seconds, and increase or decrease the value of the variable.

I would do this by seeing what location the cursor is at. For example, if the cursor was on minutes, I would write something like if(lcd.setCursor == lcd.setCursor(0,3) or lcd.setCursor == lcd.setCursor(0,4)) { minutes += 1}.

Of course these functions don't exist, so I am wondering what I can do to move a cursor and check its position.

Thanks in advance

Answer 1

Firstly, you should set the time variables outside the main loop (as a global variable). If you put them in the main loop, the time would always reset to 11:11:11 after 0.6s of delay.

lcd.setCursor == lcd.setCursor(0,3)

I dont think you can do this (unless the function returns you with the location of the cursor, have to check the header file of the library).

Instead, you should keep track of the location of the cursor with another variable (as mentioned by gre_gor), say int curLoc. But note that you have to keep track of the range of values it can go. (0 < curLoc < 16)

To summarise, the code could look like this:

#include <Adafruit_RGBLCDShield.h>
#include <utility/Adafruit_MCP23017.h>
Adafruit_RGBLCDShield lcd = Adafruit_RGBLCDShield();

int hours = 11;
int minutes = 11;
int seconds = 11;

int curLoc = 0; //Current cursor location (x-axis)

void setup() {
  lcd.begin(16, 2); //format of display
}

void loop() {
  lcd.setCursor(0,0);
  lcd.print(hours);
  lcd.print(":");
  lcd.print(minutes);
  lcd.print(":");
  lcd.print(seconds);
  lcd.noBlink();
  delay(300);
  lcd.blink();
  delay(300);

  //move cursor right;
  if (buttons & BUTTON_RIGHT) {
    //Keep the tracker in range
    if(curLoc >= 0 && curLoc < 16){
    curLoc += 1;
    }    

    if(curLoc == 3)
    { 
      minutes += 1 
     }

}