FPGA Bubble LED - HP QDSP-6064

Testing an Arria FPGA

Early prototype

Prototype on a Cyclone II board

This is a handy gadget I use during development and for debugging. It sniffs a 16-bit bus and displays the instantaneous value on a seven-segment bubble LED. No clocking or strobe required, just plug in and monitor the data. The first prototype used leaded resistors with a wirewrap socket, but the final version uses a custom PCB with surface mount resistors under the LED module. The PCB has been shared at OSH Park. I've included two source files, one for monitoring a 16-bit data bus (0x0000-0xFFFF) and the other is a binary counter demonstration (0000-9999).