LED Panel PMOD setup

Projects LED-Cubism
1

What setup is required for the LED Panel PMOD? Specifically:

  1. Which way does the panel ribbon cable connector go? Looks like the notched side faces the the middle of the board.

  2. Is the 5v/gnd two-wire connection between the iCEBreaker board and the LED panel PMOD board necessary? I see that scanlime used it in her video (~00:57), saying it’s for driving level shifters. But if it’s like other driver boards I’ve seen, it could be needed only if you want to power the LED panel from the ICEEBreaker board. So if you use a proper 5v/4A supply directly to the panel, then you don’t need the 5v/gnd two wire connection?

Scanime video: https://www.youtube.com/watch?v=aRAyVoljc_w

  1. Scanlime also changes a PCB jumper labeled “Output IO Voltage Select,” setting it to 5V (~01:33). What did that do? Again, is that necessary if you’re powering the LED panel from directly from its own power supply?

  2. In the LED panel PMOD revision I received with the kit. 1.2c, there are additional X0, X1 lines. What are they?

See schematic here: https://github.com/icebreaker-fpga/icebreaker-pmod/blob/master/led-panel/v1.2c/led-panel-sch.pdf

  1. Is there a way to test the setup? Some quick test before writing HDL? Perhaps some precompiled demo code and a shell command or script that loads it?
2

  1. Pin 1 on the ribbon cable is red. Pin 1 on the PMOD should be marked.

  2. The 5V connection is not needed. Some LED panels are finicky about being driven from 3.3V, but the panels from 1BitSquared should work.

  3. If you want to use +5V, you need to change that jumper and connecxt the +5V line. For +3V3, do neither.

  4. AFAIK, the X signals are not used. They are probably there in case future LED panels use them.

Good luck!

3

Oops, I missed number 5.

  1. Yes. You can download my github repository or tnt’s. They contain complete ready-to-build-and-download demos.


4

Re 1, for others, the connector can also easily be checked with a continuity meter ensuring that grounds connect.

Re 5, testing: Success! Assuming yosys and friends are setup (eg summon-fpga-tools):

$ git clone https://github.com/kbob/icebreaker-candy.git
$ cd icebreaker-candy/panel-test
$ make && make prog

Nice!

Thanks kbob!

5

Sorry, super n00b question. Where are the official instructions on how to hook all this up? I did a bit of searching and failed the find the official doc outlining the steps to wire everything up. I also had the same question as (1) but I’m not sure I understand kbob’s answer, or maybe I am missing something

6

Similarly, I haven’t found any documentation on how to assemble the iCEBreaker and PMODs.

The notch of the connector faces in toward the chips and other other connectors of the LED panel PMOD board. That makes the red wire of the ribbon cable at the top of board, closest to the text on the board that says “LED Panel Driver PMOD V1.2c”

The connectors go on the chip side of the board.

7

Hi…I also planned to build this setup. I have coded up a simple SPI statemachine to just try to get something written into the PMOD. I mean pure Verilog with no uBlaze.If I could initialize the board and then draw a red box and a green line… Was just about to try all that before you sent this better way forward.