Space Invaders on Proton Development Board

By : Les Johnson, creator of the Proton Plus Compiler

First published: October 2003

Introduction

After many weeks of taking an hour here and there out of my schedule to work on it, I'm happy to say my Space Invaders game is now ready. (see also revision description)

It is developed on a PROTON Develoment board using a Graphic LCD. This version uses the LCDWRITE and PLOT commands to produce the graphics Which allows smooth movements on a pixel by pixel basis.

Three (seperate) buttons control left, right and fire. It also has 3 independent sound channels. The sound interrupt is the only piece of ASM in the program, but the game itself is written purely using BASIC.

BUTTON CONNECTIONS

LEFT Button connects to PORTB.0
RIGHT Button connects to PORTB.1
FIRE Button connects to PORTB.2

Because of the 3 channel sound, the game requires an 8MHz crystal, but it will run (somewhat slower) using a 4MHz crystal.

SOUND CHANNEL CONNECTIONS

Each channel is output from PORTA.0,1,2 Channel 1.
PORTA.0 is the INVADER noise Channel 2.
PORTA.1 is the MISSILE noise Channel 3.
PORTA.2 is the SAUCER noise
Each pin should have a current limiting resistor in order to stop pin to pin shorts.

Some pictures

ADDITIONS AND CONTRIBUTIONS

This game has triggered the imagination of some users. In this section, you will find here their 'best' improvements. We would like to thank them. It shows that sharing projects is useful.

Olivier

Adding Score

By : Mark Rodgers (January 2004)

After building my own Proton board I used the Space Invaders Game written by Les to test it. I have made a very small addition to this prog by adding a high score routine that is stored in the onboard eeprom.

All the instructions are in the attached High_Score.bas file.

I have had a play with this great game for a couple of days and done some little tweeks in order to learn a bit more about how to write code a little better. It will now only work on an 18F452 as it is too big for anything else and I can not get any sound as I have no idea how to set the registers. The download is the full updated code and should run on a Proton Development Board. : Download full program

Conclusion

I hope you enjoy the game, and I mainly hope that I inspire you to create your own masterpiece.

I fancy writing a Pacman game next, then a 3D space shoot-em-up.

Have you checked out the Pong game in the samples folder of PROTON plus?

Les

October 2003

(Last revision: OdB 19/01/04)

About the Proton Development systems

Crownhill's Proton Plus Compiler is a part of the Proton Development Suite - A suite of British-developed applications enabling fast development of PICmicro's using the PICBASIC Language.

Also mentioned in this project is the Proton Development Board. Why not have a look at the PDF Manual and see what it's capable of?

For more information on the Proton Development hardware and software, please visit www.picbasic.org

Disclaimer

Please note that this project is published AS IS. No responsibility of the author in any cases can be invoqued. This project is for learning and entertainment purpose only. No vital application can be connected to it. As this project is published on a free and friendly base for the user site of PROTON +, it cannot be used in any condition for business or commercial use without explicit permission of the author.