[Oberon] PO2013 - Real time measurement

[Skulski, Wojciech]

John:
>Analog Devices Blackfin SPI devices are a nightmare.
>(Friends don't let friends do Blackfin SPI.  Those words are written in my
>personal blood, thank you for asking.)

It is not that bad in my experience. I used Blackfin a lot with very few problems. The trick was to use Analog Devices software, in particular their uCLinux. It used to be very well supported by Robin Getz and his cohort, until Analog Devices management stepped in and made "improvements" to the user community structure. The support immediately went down drain. (Sorry, Robin, it is my sincere experience.) I moved to ARM Sitara because of that. Well, if you think that Blackfin was tough then try Sitara instead. Sitara gives a whole new meaning to the word "nightmare".

Back to the topic, we used spidev under Blackfin uCLinux and it solved all our problems at the Blackfin side. The remaining problems were due to the ingenious modification of the SPI interface which Analog Devices made in their ADC chips. Namely, they combined the input and output pins into one IO pin. It saved one pin and created need to invert the pin direction with a command. What a genius has invented this idea. 

Yes, SPI can be an endless topic over a beer and around a campfire. 

Wojtek