This is what I call really cool project. Project itself is complex and requires some skills like Matlab and FPGA programming and even minor plumbing. First stage is a computer where Matlab GUI captures audio from any audio device like microphone. Then it calculates sound FFT and sends further data to FPGA board via LPT port.

ALTERA board then receives data from parallel port and according to FFT amplitudes controls 16 fountain pumps through Darlington resistor array. Project description contains plenty of videos and explanations on building this great device. Of course prototype is small enough - but if put in bigger scale it could be nice and modern attribute in various places. All project files are available here.

FPGA projects can be interesting and fun. For instance this FPGA PAC-MAN arcade game runs on Xilink Spartan3e starter kit. It actually runs on emulated Z80 CPU core.

There are 8 game available where you can switch between Pacman, Pacplus, Pong, MrTNT, MsPac, Crush Roller, Eyes and Lizard Wizard. The game is displayed on VGA screen while controlled with a joystick.

Want to try CPLD devices? It is good to start with development board for that. Here it is - a nicely made XC9572XL CPLD development board.

Development board has all I/O ports available. For quick prototyping there are six 7 segment LED indicators connected, also there are 8 LEDs connected via ULN2003A. Board is also equipped with two non symmetrical adjustable RC oscillators based on 74AC04 IC and two hybrid oscillators, piezo sounder and more. Available files for download: circuit, and operating video sample. This source may be a good start for developing your own CPLD board.

In this project LCD interfacing is based on using delay elements with Finite State Machine (FSM). Programming logic devices are different from microprocessors, because of its different structure. To achieve step-by-step program execution there is a FSM used which allows implementing series of commands (actually waveforms) with desired delays that can be sent to LCD.

As Edvin NC Mui says - generating signals would require huge amount of logic elements on FPGA, so it is better to construct a Finite State Machine that would act as microcontroller and send necessary signals to communicate HD44780 LCD. His experiment was based on Spartan-II XCS200-5 FPGA and FSM layout was synthesized by using Xilink ISE 8.1i VHDL Compiler. He achieved that device occupies 87 FPGA slices out of 2352 and his FSM can operate at speed of 108.98MHz. Full document to read And Xilink FPGA project files.

FPGA player uses same hardware part as in Super Nintendo game console. It plays .SPC music files stored in flash memory through Sony SPC700 8-bit sound chip. SPC files are more complex than usual mp3 files as they contain so called memory state of SNES sound module. Anyway this is more or less a theory, which you have to study well before start doing something.

The project is developed by using Altera DE2 board equipped with Cyclone II FPGA chip. Hardware part is written with VHDL language. 8 bit microprocessor that executes program is also emulated in software. Seems to be it is very valuable source to study, as project directory can be downloaded freely.