Arduino Uno Quick Start Manual page 175

if (nunchuk.joystick_y() > 150)
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up = true;
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if (nunchuk.joystick_y() < 70)
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down = true;
30
c_button = nunchuk.c_button();
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z_button = nunchuk.z_button();
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}
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}
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setup initializes the random number generator using some noise from analog
pin A0. Then it initializes the screen and the Nunchuk, and finally it calls
to set all global variables to reasonable values.
init_game
The loop function calls
Then it checks the game s current state in a
its work to the function responsible for handling the current state.
In line 16, loop calls a function of the TVout library you haven t seen before.
delay_frame waits for the beginning of the next vertical blanking interval—that
is, for the moment when the TV set s electron beam wanders from the bottom
of the screen back to the top. We only want to wait for the beginning of the
next frame, so we pass 1 to
because it ensures that the creation of the game s graphics in memory stays
in sync with the actual output on the screen.
Handling the Different Game States
Handling the game s different states is vital, so we define separate functions
for dealing with each game state:
Tinkering/Pragduino/Pragduino.ino
void intro() {
Line 1
tv.select_font(font8x8);
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tv.printPGM(28, 20, PSTR("Pragduino"));
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tv.select_font(font6x8);
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tv.printPGM(16, 40,
5
tv.select_font(font4x6);
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tv.printPGM(18, 74,
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if (z_button) {
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state = STARTING;
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z_button = false;
10
delay(200);
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}
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}
-
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void start_game() {
15
tv.clear_screen();
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tv.select_font(font8x8);
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tv.printPGM(40, 44, PSTR("READY?"));
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Chapter 9. Tinkering with the Wii Nunchuk
check_controls to read the current state of the Nunchuk.
delay_frame . This is necessary to prevent flickering,
PSTR("A Pragmatic Game"));
PSTR("Press Z-Button to
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switch statement and delegates
Start"));
158
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