Implemented LED panels plus added diagnostic output pins to debug FPGA

512 LED ARRAYS, TWO AT 16x16, SET UP TO OUTPUT INTERNAL SIGNALS

Due to the error in the design of the leveraged logic for driving the panels, I am only using 510 of the 512 pixels. I hooked up just about every signal in the design that might make sense to observe statically or at slow speed and still had plenty of capacity. I chose to set up the second panel of 256 with a light for each of the 203 cylinder locations, plus lights for the head selected and which of the four sectors is active. 

ADDITIONAL OUTPUT PINS ON PMOD CONNECTORS PUT INTO SERVICE

I knew that some of the pins on the PMOD connectors of the ARTY FPGA board were shared with the other input-output connectors I was already using, but upon close inspection I found that 16 signals, those on the A and B PMODS, were not shared and thus available for additional diagnostic outputs.

These are appropriate for timing or short activation detections where the LEDs are not suitable. I brought out the logic clock as well which will allow me to hook up a logic analyzer if I need to see the interplay of many signals at the same time. 

FUTURE POSSIBILITIES WITH LEARNING CURVE BUT MORE POWER

The Vivado toolchain includes some powerful tools to let me inspect and even inject signals without having to pre-select external connectors for this purpose. These are the Integrated Logic Analyzer (ILA) and Virtual IO (VIO) functionality that I can add into my design. ILA is what it sounds like, a logic analyzer with rich trigger conditions that I could use to follow signals from my PC over the USB cable to the board. VIO lets me see virtual pins and inject signals to drive my design. 

It takes hardware resources to implement these, the more signals you set up for potential connection, the more of the board is consumed. I don't have any idea whether my entire Virtual 2315 logic could coexist with ILA or VIO or both on the Spartan 7 version on my board. The more powerful factor holding me back is the time it takes to learn how to use each of these, time taken away from the project if I could otherwise finish debugging without these tools.