As part of this "documentation" I mentioned that I am doing up a reference schematic and pcb which isn't really documentation but necessary to complete the documentation. Rather than clutter up that thread with talk about chips and "should we do it this way or that?" and since it is not just about companion parts I thought it would be appropriate to start a new thread altogether.
However while revisiting USB serial chip possibilities I couldn't help thinking that this is so 2006'ish. I mean, for about the price of a USB serial chip I can pick up ESP32 parts which also support Bluetooth/BLE. Although this particular part requires support components it just seems a better interface choice for 2018 rather than just plain USB.
Even plain old Bluetooth serial or BLE serial like the nRF8001 make a lot of sense. But I rarely build serial interface circuitry directly onto a board preferring to have at least the standard 4 pins plus at least a power pin. Now that the serial boot protocol is autobauding and simplified we can talk to P2's from our smartphones and tablets easily. I know that with TAQOZ in ROM too that I don't even need an IDE or compiler of any kind.
So let's kick off this thread with this thought while we also consider what kind of chips and configurations we could use. For instance, efficient regulators that could perhaps supply both the 1.8V and 3.3V while operating from a 2.5V to 6V or more supply. Of course we will know more about power requirements in due process that we can take those finer details into account.