【東方】Lotus Land Story on a PIC18F4620

Recreation of the vertically-scrolling danmaku shooter game, Touhou Lotus Land Story on 2 Microchip 18F4620 uCs.

Project uses 2 microcontrollers. One controls game logic, user interface and screen drawing using a miniature time coordinated task scheduler. Image resources are stored on a 256MB uSD card and pulled on each frame sync (slow) but with so little RAM there was no other choice. Frame rate is steady around 8 fps, except where too many sprites are drawn to screen. Box collision takes into account velocity vectors. An object system handles all particles, enemy spawn and garbage collection. Main microcontroller syncs with second one with simple byte commands.

The second microcontroller is a slave for sound generation. Using an 8Mbit flash, data is pumped to the DAC for audio generation. An internal table holds addresses to all sound locations and their length. A separate bootloader program was used to download all the game resources into the flash from the computer using rs-232. Sound processing was done in Audacity, downsampling to 8KHz mono. Data was then encoded and downloaded using a simple program in Dark Basic Pro.

The game run has the TH02 stage 3 soundtrack, although the enemies and boss correspond to the extra of TH08. Spell that was imitated was #202 Hourai Fujiyama Volcano, but it ended up being much simpler than the original due to sprite limitations.

A WDT is set to show a blue screen of death if the main microcontroller freezes, and shows useful diagnostics information of where the program crashed. (Very useful for tricky timing settings.)

Original art & music owned by ZUN.

Technical specs:
- 12 Bit ADC MCP4725
- Screen is a uOLED-128-G1GFX.
- Flash is AT45DB081.
- uSD memory is 256 MB. (Only about 10MB used)

Category:

Gaming

Tags:

• touhou
• lotus
• land
• story
• ZUN
• bad
• apple
• anime
• animation
• reimu
• marisa
• fujiwara
• mokou
• 東方
• Microchip
• microcontroller
• uOLED
• LCD
• AT45DB081
• MCP4725
• curtain
• fire
• shooting
• PC-98
• reach
• moon
• immortal
• smoke
• eternal
• nocturne

[nintendonut888]

Wow, it IS Lotus Land Story! Right down to the smallest detail!

[Wobuffet3]

dat must be hard to play :O