CrowdSwitch hardware design files open sourced

I’m happy to announce that the CrowdSwitch‘s hardware design files (i.e. mechanical drawings, schematics, bill of materials, and PCB layout data) are now open source.


The main change to the HW design is that the XMOS IsoSwitch is now fully driven (including a per-boot firmware download) by an external SoC via Ethernet (rather than an onboard SoC via SPI). This allows more flexibility in HW selection and means we can get started building a prototype CrowdSwitch earlier because we don’t need to worry about choosing the perfect SoC. Another change is to include an xSYS 3.0 header on the board to allow flashing the XMOS chip’s OTP with a bootloader that can load the FW from the SoC via Ethernet. xSYS also allows JTAG debugging ๐Ÿ™‚

I’ve completed component selection, HW schematics, and a proposed PCB Layout. My PCB Layout work could certainly use some improvement. Let me know if you’re an experienced PCB Layout EE and want to give it a shot ๐Ÿ™‚
Much of the design was lifted from the xCORE-200 SliceKit examples. My work is all done in KiCad. If anyone has a chance to review these, I’d be super thankful! It’s all at: If KiCad isn’t for you, let me know and I’ll try to figure out how to deliver your preferred format.

I’m also looking for any advice on how to go about procuring parts and who I should look into for PCB and PCBA. I’m currently thinking of going with Seeed Studio for a batch of 5 prototype fully assembled PCBA and doing the SW bring-up work myself.

The IsoSwitch.201801 release also contains software features and bugfixes:

  • Energy tracking
  • Status and Configuration uPkts
  • Ping uPkts for bootstrapping peerย auto-configuration
  • New SwitchPort architecture allows using a single “Nexus” SoC to control a few XMOS switches at the same time
  • Standardizing on GpsTime and adding simulation
  • Refactored to split up some large files
  • Various bug fixes…

Next steps:

  • Have an experienced EE review the HW design
  • Fix the RJ45 footprint (it’s currently using a temporary placeholder)
  • Build 5-10 prototype boards over the next 6 months
  • Move the software over to match the new HW design
  • Develop more required features of the XMOS and C# switches

Discussion at Hacker News