Hi
I’m currently designing a small SpaceWire interface board for the BeagleV-Fire using the SYZYGY connector, and I wanted to verify the mechanical placement before sending the PCB for fabrication.
I used the open-source SZG-SDI-12G-Fire design and the BeagleV-Fire PCB files as references. While comparing the layouts, I initially noticed that the connector/mounting-hole coordinates did not appear to line up.
After looking more closely, I think part of the confusion is caused by the footprint origin/reference point. The SYZYGY connector footprint used in the BeagleV-Fire design does not appear to use the physical centre of the connector as its origin, so directly comparing the X/Y footprint coordinates between designs can be misleading.
Instead, I measured the location relative to the physical connector geometry and pad 1. From this I obtain the following position for the lower BeagleV-Fire mounting hole relative to the centre of the SYZYGY connector:
-
X = 0.965 mm
-
Y = 13.126 mm
Using these offsets, my PCB now appears to align correctly with the mounting holes on the BeagleV-Fire.
Could someone familiar with the BeagleV-Fire hardware confirm whether these dimensions and my interpretation are correct?
I would also appreciate any comments on the PCB itself before I send it for fabrication. It is a small 4-layer SpaceWire interface board designed for up to 400 Mbit/s with 100 Ω controlled-impedance differential pairs.
The board is intended specifically for the BeagleV-Fire and is therefore not a fully compliant generic SYZYGY pod; for example, it does not include the SYZYGY programming/identification headers and circuitry.
All project files, including the KiCad design, schematic, footprints and BOM, can be found in the repository below:
GitHub: GitHub - 4rthrl/Spacewire_connectorboard_BBVFIRE · GitHub
Thanks,
Arthur