In another post I read that Xenomai could be used for real-time tasks like control loops.
I'd need to implement a real-time task which also talks to I2C and SPI. In this mailing list message I read that the clean way to implement this in Xenomai would be an (own) RTDM Skin driver implementation for each device.
Are there any Xenomai RTDM Skins for the RPi already?
And has someone good/bad experiences running Xenomai on the RPi? I've found these three tutorials on how to set up Xenomai on the RPi.
node
,nginx
,apache
,lighttpd
for web servers that can provide web services. And Also MySQL. Then Arduino connected via UART / I2C, does the real time stuff in pure C (Arduino IDE has tons of examples and libraries) on an ATiny (~2USD) and dump the data to the Pi. If you need the aTiny to do something you convert your web service requests into data and pipe the commands into a script that pushes data via UART /I2C command the aTiny.