hackaday.com
Standalone USB-PD Stack For All Your Sink Needs
USB PD is a fun protocol to explore, but it can be a bit complex to fully implement. It makes sense we’re seeing new stacks pop up all the time, and today’s stack is a cool one as far as code reusability goes. [Vitaly] over on Hackaday.io brings us pdsink – a C++ based PD stack with no platform dependencies, and fully-featured sink capabilities.
This stack can do SPR (5/9/15/20V) just like you’d expect, but it also does PPS without breaking a sweat – perfect for your Lithium Ion battery charging or any other current-limited shenanigans. What’s more, it can do EPR (28V and up) – for all your high-power needs. For reference, the SPR/PPS/EPR combination is all you could need from a PD stack intended for fully taking advantage of any USB-PD charger’s capabilities. The stack is currently tailored to the classic FUSB302, but [Vitaly] says it wouldn’t be hard to add support for a PD PHY chip of your choice.
It’s nice to have a choice in how you want your PD interactions to go – we’ve covered a few stacks before, and each of them has strong and weak sides. Now, if you have the CPU bandwidth, you could go seriously low-tech and talk PD with just a few resistors, transistors, and GPIOs! Need to debug a particular USB-C edge case? Don’t forget a logger.
