Free-Wheeling Ferret

Assembled Ferret board

The Ferret was born out of the need to carry just too many adapters around for laptops, soldering irons, phones, etc. With more and more USB-C Power Delivery ICs coming to the market which also support the Programmable Power Supply features, we set out to build a multi-tool to support of every day (portable) hardware.
There are also more and more wall-chargers coming out supporting this feature, which makes it easier to tie the whole ecosystem together.

The Ferret itself is the prototype with a superset of features we want to support. It can be controlled via RS-485, the Host where it's plugged in or with an extra Serial over USB connector on the CTRL port.

At the heart of it is the BQ25792 which supports charging batteries (or supplying a system) with up to 5A or can also source up to 3.3A from a supply. Additionally it also supports MPPT which makes it possible to directly plug a solar panel into it. The USB-C protocol side is handeled by a FUSB307 from OnSemi. We choose it instead of the more popular FUSB302 because it also support a dead-battery mode so that we can easily charge or supply a system even if the battery voltage is too low to start otherwise.
The microcontroller is a STM32F103 for cost reasons, JLCPCB supports it as a basic part in their assembly service without any further setup cost.

Currently testing and firmware development is still in progress, so this will be updated when there is more information.