Here is the idea of very small computer of mine. Its intended usages are Gnuk, and/or NeuG.
The company name
First, the name of company is important, even if it is not (yet) legal entity.
It is named "Flying Stone Technology" after my place in Maebashi.
And the ASCII art is important too. Here is the first one.
,. --- :o ; --- Flying Stone Technology `' ---
Flying Stone Tiny 01 is the name of the computer. In short, FST-01.
FST-01 is USB bus powered device, with LED and an extension I/O pin.
The chip for FST-01 is STM32F103CBT6.
LQFP 48-pin version, as QFN is difficult for assembly.
128KB flash memory is enough. 20KB RAM is not that huge, but it is good for Gnuk.
The method of writing Flash
JTAG requires at least five lines (JTCK, JTMS, JTDI, JTDO, and GND). Serial writing needs pull-up of BOOT0 and three lines (RX, TX and GND).
For minimal footprint, SWD looks good, it only requires three lines (SWDIO, SWDCLK, and GND), and no needs for BOOT pin(s) setting.
The port has three lines; VDD, GND and PB0.
Only one bit I/O is supported, thus, the name 01.
We can connect consumer IR receiver to this port.