[Oberon] PO2013 - Real time measurement

[Tomas Kral]

> You can connect as many slaves to the ribbon as you wish, but you can
> only communicate with a single slave while others are not active.

Wojtek,

Thank you, I wanted to achieve a small system bus for Oberon devices,
inexpensive, with as few components as possible. I learnt SPI cannot be
addressed, but only chip selected by `CS'. My idea was to drive `CS'
by Oberon through `GPIO' + interrupt, being a master letting only one
party to talk, the other listen, at at time.

Thus having a simple HUB, for some A/D sensors. Alternatively to have
also D/D, D/A outputs.

Designing a small control system, so to speak. 

-- 
Tomas Kral <thomas.kral at email.cz>