WARN: 🚧 under construction! 🚧 - this hardware is under active development
SoldierCrab is an embeddable FPGA SoM (System-on-Module) designed for use in high-speed audio and USB applications. It is the brain of tiliqua and other apfelaudio products.
SoldierCrab has the following core features:
- ECP5 FPGA (-25K or -45K variant in caBGA256 package)
- HyperRAM / oSPI-RAM (tested up to 400MByte/sec)
- USB2 PHY with exposed ID, it can be used in device or host mode
- 1V1 / 1V8 / 2V5 regulators onboard, 3V3 is all that's needed
- PROGRAMN internally exposed for multibooting bitstreams
- 2 indicator LEDs on the PCBA
- 48MHz master clock
- Card edge is basically: 47 exposed general purpose pins + 4-pin JTAG + USB2
- 22mmx22mm board size with M.2 E-key card edge (see 'Physical Compatibility' below)
There are currently 2 revisions of SoldierCrab in the wild.
- R2.0: LFE5U-45 with 7KL1282GAHY02 (3.3V HyperRAM, tested up to 200MB/sec)
- R3.0: LFE5U-25 with APS256XXN-OBR (1.8V oSPI-RAM, tested up to 400MB/sec)
PDF schematics for both can be found in the schematics-pdf folder.
The SoldierCrab is 22mmx22mm (+/- 0.3mm) with an M.2 E-key connector and offset mounting hole. The mounting hole is offset such that this board is physically compatible with the SparkFun MicroMod format, however we do not claim electrical compatibility with it (even though this SoM will work with some MicroMod boards, the JTAG and I2C connections are in the wrong place for us to claim complete compatibility - this is intentional design choice to save routing space whilst trying to remain close to some kind of SoM standard).
On my carrier boards, as a connector I am using a TE Connectivity 2199230-4.
A nice resource for designing appropriate carrier boards can be found here. However, keep the above in mind, make sure your JTAG and I2C pinouts match the SoldierCrab ones.
Aside from in the schematic, you can find a (tested!) version of the SoM pinout in amaranth-boards format here in the Tiliqua repository.
6 are adjacent on the same side:
[(13, 15), (20, 22), (52, 54), (58, 60), (62, 64), (68, 70)]
2 are almost adjacent (1 pin gap) on the same side:
[(55, 59), (67, 71)]
10 not adjacent (>1pin gap or different sides):
[(6, 17), (11, 19), (34, 35), (38, 41), (37, 43), (40, 47), (46, 57),, (63, 69)]
If you are interested in prototyping with this SoM, feel free to send me an email. They are not generally available yet, but I plan to make it available on my store soon.
- The Cynthion project from Great Scott Gadgets.
- The OrangeCrab project from Greg Davill.
- Sparkfun Micromod.
Copyright (C) 2024 S. Holzapfel, apfelaudio UG (haftungsbeschränkt)
The files in this project are largely covered under the CERN Open-Hardware License V2 CERN-OHL-S, mirrored in the LICENSE text in this repository. This LICENSE and copyright notice do NOT apply to imported artifacts in this repository (i.e datasheets, third-party 3D models, symbols or footprints), or to dependencies released under a different (but compatible) open-source license.
If you create or manufacture your own derivative hardware, the name "apfelaudio", the names of any apfelaudio products and the names of the authors, are not to be used in derivative hardware or marketing materials, except where obligated for attribution and for retaining the above copyright notice.
For example, your modified version of "apfelaudio SoldierCrab" could be called "Sandy Modular - Clawcruncher".