Arduino uno User Manual

Admittedly that’s a lot of code, but you know most of it already, and the new
parts are fairly easy. In the first line, we include the Bounce2 library we’ll use
later to debounce our two buttons. Then we define constants for the pins we
use, and we define the variable guess that will hold the player’s current guess.
The Bounce2 library declares a class named Bounce , and you have to create a
Bounce object for every button you want to debounce. That’s what happens in
lines 11 and 12.
In the setup method, we initialize all our pins and set the random seed. We
also initialize the serial port, because we’ll output some debug messages. In
lines 20 to 23, we initialize the two Bounce objects. The attach method connects
a Bounce object to a certain pin. With the interval method you can set a button’s
debounce delay in milliseconds.
Our loop function has been reduced to two function calls. One is responsible
for dealing with guess button pushes, and the other one handles pushes of
the start button. In handle_guess_button , we use the Bounce class for the first time.
To determine the current state of our guess_button object, we have to call its
update method. Afterward, we read its current status using the read method.
If the button was pressed, its state is set to HIGH , and we increment the guess
variable. To make sure that the guess is always in the range between 1 and
6, we use the modulus operator ( % ) in line 36. This operator divides two values
and returns the remainder. For 6, it returns values between 0 and 5, because
when you divide a number by 6, the remainder is always between 0 and 5.
Add 1 to the result, and you get values between 1 and 6. Finally, we output
the current guess using the three LEDs, and we also print it to the serial port.
The handling of the start button in handle_start_button works exactly the same
as the handling of the guess button. When the start button is pressed, we
calculate a new result and output it on the serial port. Then we check whether
the user has entered a guess ( guess is greater than zero in this case) and
whether the user has guessed the correct result. In either case, we print a
message to the serial port, and if the user guessed right, we also call the hooray
method. hooray lets all three LEDs blink several times.
At the end of the method, we wait for two seconds until the game starts again,
and we reset the current guess to zero.
After you’ve uploaded the software to the Arduino, start the IDE’s serial
monitor. It will print the current value of the guess variable whenever you
press the guess button. Press the start button, and the new result appears.
In the following figure, you can see a typical output of our binary die.
Chapter 3. Building Binary Dice • 58
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Arduino uno Specifications

General

Form factor	Arduino
Certification	RoHS, FC, CE
Processor model	-
Processor frequency	- MHz
Microcontroller model	ATmega328
Microcontroller frequency	16 MHz
DC input voltage	7-12 V
Operating voltage	5 V
DC current per I/O pin	40 mA
Flash memory	0.032 MB
Maximum internal memory	- GB
SRAM (Static Random Access Memory)	2 KB
EEPROM (Electrically Erasable Programmable Read-Only Memory)	1 KB
Wi-Fi	No
Number of analog I/O pins	6
Number of digital I/O pins	14

Weight and Dimensions

Board dimensions	53.4 x 68.6 mm