Another Octopi Hat project

So looking for input, here is my design for a hat for my Pi. Its meant to be a fast and simple solution to all of the random cables in my GPIOs. Its meant to be super easy through hole all the way, and honestly, parts I had laying around. I thought about putting voltage conversion on board, but I already have an Aliepress converter, so why waste the space.

Let me know if you want to see a schematic, but its pretty straightforward.


I'd probably be interested in seeing what you had before this.

Sadly I don't have any pictures, I started my "Grand Lack Table Build" so I am attacking everything fresh. Here is what I am looking at having:

Print enclosure;
LED lights across "top"
LED lights on gantry (gave myself options for addressable or not on shield)
DH22 environment sensor
Pi controlled 120mm exhaust fan

Electronics enclosure under table (longer term project)
DH11 temp sensor
Pi controlled exhaust fan
+v for a PI case fan until I build out the full electronics enclosure

With all electronics underneath I am going to put a 5" HDMI touch screen off the pi for control.

Its not a ton, but the spaghetti mess really annoys me. This project will cost me about Β£10 as I have almost all the parts and really only need to get the board printed. So well worth it in my opinion.

I guess I'm trying to wrap my head around what's happening...

  • Q1 through Q3 control the individual aspects of RGB in four LED connection points (X3 through X6)...?
  • It looks like aRGB0 and aRGB1 aren't interconnected with those
  • And you've got two more transistors running fans FAN0 and FAN1 but not FAN, I'd guess

Hit the nail on the head. aRGBs are addressable, which I haven't used, but would like to eventually incorporate. Looking about it looks like they are run off of SPI, so I used both for two dedicated addressable RGB ports. 4 RGB are good old FETs for driving one "set" running off the 4 connectors.

The FAN connections is just convenience for plugging in a case fan for the Pi itself. I have tons of JST connectors of all shapes and sizes, so why not make it nice.

Do you have a good supplier for JST connectors? I suppose I could chase them on Digikey perhaps.

Honestly I have Aliexpress'ed just about everything. Hence me having loads of spare bits about.

After this hat I'm hoping to design a more advanced version with power conversion and what not on board with SMD likes some of the nicer hats bouncing around.

One cheap step at a time however.

Believe it or not, I have had tremendous luck with Amazon lately when it comes to crimp-on connectors, ie. board-to-board, board-to-harness, harness-to-harness, etc. Plus you get it in a day,

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