FPGA/CPLD 16x2 LCD Interface

Parts DIY CPLD Dev Board
EPM7128SLC CPLD
16x2 LCD Display
5kΩ Trimpot
1uF Capacitor
ByteBlasterMV
Wirewrap
Wirewrap Tool
SIPs
9v Connector
Battery Holder

Parts List Details
           Some of the parts listed above might be new to you, so take a look below where I have described the main parts in more detail.

DIY CPLD Dev Board
           For this project I will be using the CPLD board I built a few years ago. The CPLD that is on the board is really old by today's standards, however the same theory for operation will apply no matter which FPGA or CPLD you choose to use. This board has a JTAG programming connector, power supply and 7 segment LED connections already made.

16x2 LCD (HD44780)
           This is the LCD module that we will be displaying characters on. It has an HD44780 compatible interface which means it follows the most common standard use with this type of LCD module. This means the code we develope here will be very re-usable.

5kΩ Trimpot
           The contrast element for the backlight LED will be controlled by turning the knob on this trimpot back and forth between 5kΩ and 0Ω

ByteBlasterMV
           To load the VHDL module and configuration into the CPLD we will use a ByteBlasterMV that I built a few weeks ago. It's on a breadboard. Alternatively you could buy a used one of these things on ebay for like $10.

Wirewrap
           All connections are made using standard Wire Wrap and a Wire Wrap Tool. This is rather time consuming and requires some discipline, but it's cleaner than a breadboard prototype and quicker than a PCB prototype.

Battery Holder
           You can use whatever power supply you like. I use an array of rechargeable batteries. CPLDs and FPGAs require a lot of power to operate, so you'll need to recharge your batteries once or twice through the project.