I bought the Mindstorms v4 / advanced hub (in set 51515). It's a good set, and the Hub has some great features - notably a rechargeable battery, the ability to run "live" off of USB power, and a full 6 ports (the minimum, IMHO; covers most working equipment such as fully-motorized excavators, etc.)
However, the battery lacks capacity, and the drive voltage of the motors is underwhelming. USB-C PD is also lacking, and would be a huge feature as it would allow 9v power from cheap COTS battery packs.
I went searching for a BuWizz/sBrick/etc. type replacement; I can't find anything except for a current Kickstarter (no link, as I backed it and and don't want any perceived advertising here - but it does look interesting, supports Arduino, check it out :) )
Are there any aftermarket hubs in the works you're aware of? Any supporting info such as ETA or experience of the creators, etc., would be helpful.
I'm starting to think I may need to DIY; the PUP connectors themselves are available only from China (are there any patent concerns?), but are cheap enough. It looks like the specs and i2c protocol bits are all reasonably well documented. IMHO, an ideal setup would:
- support a higher drive voltage for the motors.
- the onboard https://www.onsemi.com/pub/Collateral/LB1836M-D.PDF supports 10.5 abs max.
- even a consistent 9V would be a HUGE improvement; a 3s1p lithium ion pack, plus a 90%+ efficient buck converter board to ~9V seems feasible?
- side benefit of 9V is it could also be driven from a USB-C PD board set to 9V (although muxing this with the battery isn't trivial or supported by any of the cheap boards I can find from Aliexpress or US hobby sites.
- support lots of channels; 8 or more? Most microcontrollers or SBCs should be able to drive at least this many channels of motor controllers.