In this session I will walk you through how to build your own retro handheld console that is powered by Java, runs on a Raspberry Pi, and is printed on a 3D printer. Some of the topics that we will cover along the journey include: • Hacking Java on the Raspberry Pi • Rigging input devices with Pi4J • Insane performance tuning on the JVM • Why your boss [or SO] needs to buy you a 3D printer! And of course your retro gaming mettle will be put to the test, so make sure to dust off your old 8 and 16 bit consoles to prepare. This presentation is about the most fun you can have while still legitimately calling this conference “work.” In fact, I will hopefully inspire you to do your own creative “work” leveraging Java and Raspberry Pi to hack the real world.

1. BYO Java RetroPi Console
Stephen Chin (@steveonjava)
Lead Java Community Manager
JavaOne Conference Co-Chair

2. Java Community Management is pretty hard…
314
Java User Groups 9M+Java
Developers
150+ 150+
Java Champions
50+ JUG groups
contributing
to JCP
2
Community

3. 3
NEW CHALLENGER!!!

4. Emulating the NES is a real challenge!
826
ROMs to Test
Plus Homebrew!
92M
61 Million Units
Sold Worldwide
3,510
Transistors
Synchronization
Points
4
Nintendo
Entertainment
System
https://commons.wikimedia.org/wiki/File:RP2A07.jpg

5. 5

6. 6

7. 7

8. Up-Up-Down-Down-Left-Right-
Left-Right B, A, Start
8

9. 9

10. Electronics
10

11. https://commons.wikimedia.org/wiki/File:Raspberry_Pi_2_Model_B_v1.1_front_angle_new.jpg
=
Have Java With Your Dessert

12. http://elinux.org/File:Raspi-Model-AB-Mono-2-699x1024.png

13. And what are these for?
http://i.imgur.com/k0Puu.jpg

14. Portable Display Options
Graphics Bus Quality Speed Power Usage
Composite Low Fast High
HDMI High Fast High
SPI High Slow Low
Device Tree High Fast Low
14

15. Adafruit Kippah
• Connects to 40 pin LCD connector
• Connects display via Device Tree GPIO
• Powers Display off Raspberry Pi 5V VCC
• Optional touch support via USB
• Uses I2C, UART, and SPI pins… only 6 GPIO left over
15

16. NES Controller
16
1
2
3
45
6
7
8

17. 17

18. Diodes to the Rescue!
19
Left
Right
Start

19. 20

20. Button Layout
21

21. Soldering to the Kippah
22

22. All Wires Connected
23

23. 24

24. Java HalfNes Emulator
25

25. HalfNes Project
26
https://github.com/andrew-hoffman/halfnes

26. 27

27. 28

28. 29

29. 30

30. 32

31. Which Are the Real Performance Bottlenecks?
• Swing Video via X-Windows
• Synchronization between CPU, PPU, APU
– Return to per-line instead of per-pixel
• Bitwise Helper Functions
• Extracting PPU Operations
• Replace APU Double Math with Longs
• Array Access via Unsafe
• Replace loops with System.arraycopy
• PWM Audio
33

32. HalfNes Performance Bottlenecks
• Swing Video via X-Windows
• Synchronization between CPU, PPU, APU
– Return to per-line instead of per-pixel
• Bitwise Helper Functions
• Extracting PPU Operations
• Replace APU Double Math with Longs
• Array Access via Unsafe (Doesn't actually help)
• Replace loops with System.arraycopy
• PWM Audio
34

33. 3D Printing a Case
35http://vidal-design.deviantart.com/art/Mario-Versus-Bullet-Bill-3D-printed-402524749

34. Ultimaker 2
36

35. 37

36. 38

37. 39

38. 40

39. Hinge Design
42

40. 43

41. 44

42. 45

43. 46

44. 47

45. 48

46. 49

47. 50

48. 51

49. 52

50. 53

51. 54

52. 55

53. 56

54. 57

55. 58

56. 59

57. 60

58. 61

59. 62

60. 63

61. 64

62. 65

63. 66

64. 67

65. Instructions on Thingiverse
69
http://www.thingiverse.com/thing:993901

66. Raspberry Pi with Java
70
raspberrypiwithjava.com

67. Stephen Chin
tweet: @steveonjava
blog: http://steveonjava.com
nighthacking.com
Real Geeks
Live Hacking
NightHacking Tour

68. Safe Harbor Statement
The preceding is intended to outline our general product direction. It is intended for
information purposes only, and may not be incorporated into any contract. It is not a
commitment to deliver any material, code, or functionality, and should not be relied upon
in making purchasing decisions. The development, release, and timing of any features or
functionality described for Oracle’s products remains at the sole discretion of Oracle.
72