Check if a button is pressed with Registers

Projects Programming
1

Hello, I need a little bit of help. I want to make a main menu on lcd display, and I want to connect 3 button, Button1: left Button2: Ok Button3: right
I only have free pin in Analog side, so I connected the 3 buttons to A0 A1 and A2.

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This is my project.

I already figoured it out that I have to set the PC0 PC1 and PC0 pin to Input.
DDRC&=0b11111000; like this. But i dont know what to write in the Loop().
Can somebody help me?

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2

Use pinMode(A0, INPUT_PULLUP); and if (digitalRead(A0) == HIGH).

3

Are you asking for help writing to the LCD or are you asking for help with the Keypad.

The keypad is set in a matrix fashion of Rows and columns. So R1 and C1 is key 1 etc.
note that either the rows or the columns have to be an Input and the other an output for the system to work like a wire. Its incredibly simple.

The LCD is another matter as I have not messed around with these yet.

4

If you like the "Register" way, maybe this :

void setup() {
  // put your setup code here, to run once:
  DDRC &= 0b11111000;
  PORTC |= 0b00000111; // A0-A2 as PullUp
  // pinMode(A0, INPUT_PULLUP);

}

void loop() {
  // put your main code here, to run repeatedly:
  if((PINC & 0b00000001) == 0) {  // Test bit 0 only
    PORTB |= 0b00100000;          // BUILTIN_LED pin 13 On
  } else {
    PORTB &= ~0b00100000;         // BUILTIN_LED pin 13 Off
  }
/* or this way
  if(PINC & 0b00000001) {   // Test bit 0 only
    PORTB &= ~0b00100000;   // BUILTIN_LED pin 13 Off
  } else {
    PORTB |= 0b00100000;    // BUILTIN_LED pin 13 On
  }
*/
}

with PullUps