Intel Edison generic calculator shield photo journal

[Paul Dale]

I completely fail to understand why real time is critical in a calculator. Wait for a button press, run as fast as is reasonable to get a result. The only timing based parts are power saving and the pause command and neither of these could be considered critical enough to warrant real time support. Perhaps the display and keyboard are timing based, but again they aren't critical -- nobody is going to notice a few hundredths of a second skew occasionally.

Sure device drivers need moderately accurate timing but the Linux kernel supplies this. If you are driving raw timing critical hardware in a user application, then I rather suspect you are doing something very wrong.

My experience with embedded Linux on a variety of platforms, much slower than the Edison, is that user programs have perfectly reasonable timing characteristics for most purposes. Not hard real time but usually good enough.


- Pauli