Idea: SBC board shape (Raspberry Pi 5 / 4 / 3 B+ / Zero 2 W, BTT Pi) + Micro-HDMI port opening

[plazmabokor]

Hi Stefan,

two related ideas, before I build anything:

1. An "SBC board" shape in the library. You pick the board type, and Layerling places it true to size: the outline, the mounting holes, and the connectors and larger chips as simple blocks at their real positions and heights. It helps when designing around a board, for example where a heatsink goes or where a Port opening has to sit in front of a connector.

First boards: Raspberry Pi 5, Pi 4 B, Pi 3 B+, Pi Zero 2 W and BIGTREETECH Pi V1.2.

The data comes from the makers:

• the Raspberry Pi mechanical drawings (Pi 4, 3 B+, Zero 2 W)
• the official Raspberry Pi 5 STEP model
• BIGTREETECH's own 3D model

A few values are not given by the makers (for example the Zero 2 W hole diameter and some connector heights). Those are estimated and marked as such in the code.

One finding from this: the BTT Pi is not fully Pi-compatible. One mounting hole is 5.9 mm off the Raspberry Pi position (second picture). So the board data has to be exact per board.

2. Micro-HDMI in the Port opening shape. It is the HDMI type on the Pi 4, the Pi 5 and the BTT Pi, but the Port opening list doesn't have it yet. I'd take its size from the connector maker's datasheet.

The pictures are rendered from the collected data, not from Layerling. Would you like these in Layerling? If yes, I'd start with the Micro-HDMI, then the board shape.

[henmedia]

@plazmabokor Yes, both are welcome, and starting with Micro-HDMI is the right order. It's a small addition next to the Mini HDMI that's already there.

For the board shape, a few things so it fits the rest of layerling:

• The board should come out as an exact CAD body (outline, holes and blocks), so the edge tool, STEP export and boolean cuts work on it like on the other library shapes.
• An MCP action for it (pick the board type, place it), and the board type in the .lyl check.
• A "?" help text on the new card, and a line in the README and on the start page.

Marking the estimated values in the code is exactly right, and good catch on the BTT Pi hole. Two PRs, one per feature, would make reviewing easier.

[medmed58]

Hi @henmedia,
I would like to request the addition of the BIGTREETECH Pi4B (Raspberry Pi Compute Module 4 Carrier Board) to the Layerling SBC list.
I have verified the exact dimensions and footprint. Here are the technical details for integration:
Dimensions: 85.0mm x 54.29mm
Mounting Holes: 4x M2.5 at corners (3.49mm from edges)
Key Connectors:
1x Ethernet (RJ45)
4x USB-A 2.0
2x Micro-HDMI
1x USB-C (Power/Data)
40-pin GPIO header
CSI/DSI connectors
I have attached the official dimensioned drawing and a 3D footprint view for reference.
[Joins tes 2 images ici : le plan de cotation + la vue 3D SolidCraft]
This board is very popular for 3D printer mainboards (Klipper/Mainsail). It would be great to have it in the default list!
Thanks!
BIGTREETECH PI4B Adapter V1.0(No CM4)-footprint.zip

[henmedia]

@medmed58 Thanks for the request and for the drawing and STEP file, that makes it much easier. One small note: going by BTT's drawing, the four holes aren't at the corners but on the Raspberry Pi 4 pattern, 58 × 49 mm (3.5 mm and 61.5 mm from the left edge, 3.5 mm and 52.5 mm from the bottom).

@plazmabokor The SBC board shape is your module. Would you like to add the BIGTREETECH Pi4B? Everything needed is attached above.

@medmed58 And if you'd like to support layerling, here's where you can chip in – thank you!

[plazmabokor]

Thanks for your interest; I’ll be able to continue the work on Friday evening...

[medmed58]

Hi, thanks for the feedback. I'm not sure I fully understand the note about the hole positions.
The STEP file and dimensioned drawing I provided are the official files from BIGTREETECH's own GitHub repository. The mounting holes in those official documents already follow the Raspberry Pi 4 pattern (58×49 mm, ~3.5 mm from edges), as shown in the attached drawing.
Could you clarify if there is a specific discrepancy you see between the official BTT files and what Layerling expects? I want to make sure I don't modify an official manufacturer file incorrectly."

[henmedia]

@medmed58 Sorry for the confusion, there's no problem with BTT's files, and nothing needs changing. My note was only about the summary in your post, "4x M2.5 at corners (3.49 mm from edges)": on an 85 mm board that reads as if all four holes sat in the corners, while the two on the right are at 61.5 mm, as the drawing shows. The official drawing and STEP file are exactly what's needed.

[medmed58]

Thank you for the clarification! I'm French and I translate messages from English, which can sometimes lead to misunderstandings in my wording. I apologize for the confusion caused by my text description.
I'm very glad to hear that the official BTT STEP file and drawing are exactly what's needed. Looking forward to seeing it integrated into Layerling!
By the way, BIGTREETECH has many other well-documented products (motherboards, displays, expansion modules) with official STEP files and dimensioned drawings available on their GitHub. Would you be interested in receiving more of these for the Layerling library? I'd be happy to help add them."

[henmedia]

@medmed58 No need to apologize, your post was clear enough, and the drawing said the rest. As for more BTT products: thanks for the offer. I'd rather add them one at a time, when someone actually needs a specific board, than fill the library ahead of time. If you have one in mind for a project of your own, open a new post in Ideas for it, with the link to BTT's drawing and STEP file like you did here. That makes it easy to pick up.

[medmed58]

I need to report an issue with the existing 'BIGTREETECH PI V1.2' model in your library.
Since I own both boards (BTT PI v1.2 and BTT Pi4B), I wanted to model another enclosure out of curiosity using Layerling with the PI v1.2 card. That’s when I realized that the built-in model does not match my physical board at all.
I then checked against the official BIGTREETECH STEP file and drawings, and they confirm that the current Layerling model is incorrect.
Current Layerling Model: Shows a compact board (~91 mm) with side-by-side USB/Ethernet ports.
Official BTT PI v1.2: Is a longer board with a green power terminal block on the left and a completely different port layout (see attached comparison).
Users designing enclosures with the current Layerling model will end up with parts that do not fit the real hardware.
I have the correct official STEP file and dimensioned drawings for the real BTT PI v1.2. Would you like me to send them so you can replace the incorrect one?
Thank you!

BIGTREETECH_Pi_V1.2.zip

[plazmabokor]

Thank you, I will fix it.

[plazmabokor]

@medmed58 thank you for the report and for the maker's STEP - you were right, the BIGTREETECH Pi V1.2 was a mirror image. I compared it with the STEP (mounting holes and 13 parts) and turned the board the right way round: with the USB and Ethernet at the right end, the USB-C, micro-HDMI and power terminal are now at the back edge and the GPIO header at the front, as in the maker's model. The fix is in PR #1356.

[henmedia]

@plazmabokor thank you for checking it against the maker's STEP so carefully.

@medmed58 thank you for spotting it and for sending the files. The BIGTREETECH Pi V1.2 in layerling was a mirror image of the real board, which is why the ports were all in the wrong places. The fix is merged: the USB-C, micro-HDMI and power terminal are now at the back edge and the GPIO header at the front, as on your board.

[henmedia]

@medmed58 the corrected BIGTREETECH Pi V1.2 is out in layerling 1.145.0: the USB-C, micro-HDMI and power terminal are at the back edge and the GPIO header at the front, as on your board. Thanks again to @plazmabokor for the fix.

[medmed58]

"Thank you, you're doing an excellent job. Well done!