I’d love to have a module around that can connect my Framework laptop with an 802.15.4 network, typically 6LoWPAN (same radio as Zigbee). A widely available chip for that is the nRF52 family (eg. nRF52840), which has a Cortex-M core, a USB 2.0 interface and a 802.15.4/BLE/proprietary radio.
Given radio stuff is hard and components are fiddly, it could be built from a SMT module such as the MDBT50Q-1MV2. At a first glance, the 2.1mm high module could fit well on the bottom side of the retrofit expansion card; the screw positioning might be detrimental to the antenna performance.
Usage-wise, this could do either of two things:
- Serve as an 802.15.4 adapter. This probably needs a custom driver and firmware.
- Serve as an 802.15.4 NIC. A trivial program in RIOT OS could provide full access to an 802.15.4 network, and expose the link as an Ethernet card.
- Act as a remote access to the Debug Accessory Mode of the EC (probably needs a few resistors and probably a solder jumper).
- Custom development: Such a module would enable RIOT OS users to always have an embedded module at hand, which they can use and flash without extra peripherals. Programming would be done via bootloader; as a failsafe, it’d be good to have exposed pads to attach a debugger.
BOM-wise, I think this could be literally just the USB plug and the SMT module (usage as DAM could need a few small parts).
Is there anything that should be reasonably added just because it’s trivial (and doesn’t cause trouble when not populated)?