Re: Raspberry Pi, Real-Time and Ada

["Rego, P." <pvrego@gmail.com>]

> I went back and had a closer look at this. (I've never actually used
> Linux to drive GPIO lines as I either use a dedicated RTOS or just
> write the code for bare metal mode).
> It appears there are two ways of accessing the GPIO lines on the
> Raspberry Pi under Linux: either via the /sys/class/gpio interface
> or directly via memory mapped I/O.
> It looks like all the types of performance comments I remember come
> from the first access method and that you can get far better access
> times using the second method.
> Which method are you using ?

At this time in RPi, none of them. For now I am still studying the board before coding, as I should port an application to it in the next days. But I am still evaluating if the RPi serves to my app. Timing constraints are the top concern. But there as others, for example I just have 1 PWM exposed in RPi and I would need at least 4; this is a minor concern if I can control some GPIOs using timers, or use an external board to do it for me, but it would be better if I had more PWM.

Rego.