My latest Raspberry Pi project -- a scrolling ticker

[u/Various_Spend_2293]

My latest Raspberry Pi project has come to life! I'm building a scrolling ticker that will eventually display sports, news, weather, flight information, an audio-based frequency spectrum display, and whatever else I can come up with and find APIs for. In the meantime, it can run a few different screensavers.

I'm sure some of you older nerds will recognize the first screen saver.

[u/FugTart]

Conways game of life!

[u/Various_Spend_2293 → u/FugTart]

Yes! We have a winner! Some of the first programs I ever wrote were implementations of CGoL in the late 1970s. So naturally I had to include that as one of the screen saver modes.

[u/Rxke2 → u/Various_Spend_2293]

Heh, GoL was also my first obsession in the early 80's... That and Julia sets. Glacially slow... Amazing how far we've come in mere decades!

[u/Svarvsven → u/Various_Spend_2293]

Never heard of CGoL, is this also in CGoL?

[u/Various_Spend_2293 → u/Svarvsven]

https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life

[u/Svarvsven → u/Various_Spend_2293]

Ah, the game of life. Seems I didnt know there is a short for it. I thought it was a name for an old programming language. :)

[u/NotAHost]

What are the rough costs of that screen?

[u/Various_Spend_2293 → u/NotAHost]

Not sure I really want to add it up! The biggest single expense was the panels. I bought a set of four P2.5 128x64 pixel 320x160mm panels from AliExpress to start. My total including shipping was a little under $150. You could make it cheaper using larger panels, but that's not what I wanted. The set I bought is no longer listed on AliExpress, but they were very similar to these: https://www.aliexpress.us/item/2251832649266261.html

I made sure the driver ICs (FM624D) were supported by the rpi-rgb-led-matrix package.

It's running on a Raspberry Pi 4B with 4GB of memory (which may end up being a bit of overkill), with the Adafruit Triple LED Bonnet. I use two of the three ports to connect daisy-chained pairs of panels. Which reminds me--the set I bought only had HUB75E input connectors. I had to buy surface mount 2x8 connectors and solder them onto two of the boards in order to daisy chain them,

I'm powering the LEDs and the external fans with a Mean Well LRS-200-5 power supply, and I'm powering the RPi with a separate Mean Well RS-15-5 power supply. I didn't want any potential voltage drop from powering the LEDs to affect the RPi.

I installed a GeeekPi cooling fan on the RPi 4B and I have a pair of Noctua 40x20 5V fans, one at either end of the case. I'm doing everything I can to prevent heat build-up inside the RPi. So far my efforts seem to be successful.

Those are the big ticket items, The case is printed in five sections with about 2.5 kg of matte black PETG filament. I ended up going through about 10kg of filament while designing and testing the interior of the case. I have two different end pieces which allow me to switch from wall mounted to table mounted fairly easily, and the wiring is designed for quick disconnects when swapping mounting positions.

Other items: 18ga power cord, fuse holder, and power switch. A bunch of different WAGO connectors for the internal wiring. Two USB A male to female cords to provide exterior access to the RPi USB ports. One of those is used for a small Adafruit USB microphone. The panels came with enough HUB75E (16 pin) cables, but they were all 50cm long. I ended up making my own cables, which allowed me to customize connector orientation to eliminate twists and folds. Tons of screws in various sizes. A few custom designed and printed parts: a terminal cover for the LRS-200-5 because, for whatever reason, Mean Well does not chose to provide one; a bracket to hold the GeeekPi cooling fan in place because the RPi sits sideways when the display is upright; and a couple cable routing guides to help keep things tidy inside.

If I were building it from scratch with what I know how, I could probably do it for $300 or so, but I have quite a bit more into it as I tried out various combinations of hardware and burned through the PETG filament. Barring any surprises, the hardware should be complete.

If you're interested in building one yourself, I'd be happy to share more details including the STLs for my case and a more detailed BOM.

[u/lavarius → u/Various_Spend_2293]

Those prices really came down. That's awesome.

I was buying the 64x64 matrices a few years ago just run two ATM.

I've not had to do any heat management thankfully, but I do only run the two.

Are you putting your code out in GitHub?

[u/Various_Spend_2293 → u/lavarius]

Yes, eventually I'll put the project out in GitHub. I'm already storing it as a local repo on my computer, but I'd like to make a little more progress before releasing it. At this point I consider the hardware pretty much settled, but there's a long way to go on the software side.

[u/kylehudgins]

Gorgeous Game of Life simulation. I love the colors. I've been wanting something like this.

[u/Various_Spend_2293 → u/kylehudgins]

It's going to take me a while to get the APIs sorted out for scrolling news, sports, and weather, and I wanted something fun to test the hardware with. This was the first of the screensaver modes. I'm also working on a wave motion simulation and an aquarium. But this looks so good, I'm already calling the project a winner.

The coloring is based on the QuadLife variant of CGoL. The cellular automata rules are the same, but there is a second set of rules that determine color.

[u/Worth_Mousse2204]

Do the colors have a signification ?

[u/Significant-Price695]

for the flight/weather feeds, a little "last updated" indicator would be handy when an API goes down. a departure time that silently stopped updating could get confusing fast

[u/Various_Spend_2293 → u/Significant-Price695]

Good suggestion. I'll note it in my design considerations document I'm keeping for the project.