ESP - Week 3

Question 1

What do #define UP 1 and #define DOWN 2 do

Answer 1

Everything UP or DOWN is replaced by 1 or 2 respectively

Question 2

Macro pre-processor Syntax

Answer 2

#define (original) (replace)
no semi colon

Question 3

Define a two argument macro

Answer 3

define twoargmacro(a,b)

Question 4

Declaring functions

Answer 4

output function_name(input){}

Question 5

Button masks

Answer 5

#define BUTTON_UP 0x08
#define BUTTON_DOWN 0x04

Question 6

Fixing button up and button down

Answer 6

both_pressed = (x & BUTTON_UP) && (x & BUTTON_DOWN)

OR

both_pressed = x & (BUTTON_UP | BUTTON_DOWN)

Question 7

Difference between & and &&

Answer 7

& = Bitwise And
&& = Logical And

Question 8

What is Bitwise OR

Answer 8

|

Question 9

What is Polling

Answer 9

When we continually check if something has changed

• busy wait
• low level

Question 10

What is an event

Answer 10

When we wait for something to happen until one of them does

- high level

Question 11

Arduino Buttons

Answer 11

lcd.readButtons() - returns the current state of buttons