Re: [Firmata-devel] Merging the hardware abstraction branch

[Sebastien L. <seb...@gm...>]

Hi Paul,

Thanks for your reply

2010/7/20 Paul Stoffregen <pa...@pj...>
>
>
> Very briefly, Firmata is built on top of the Arduino functions like
> pinMode, analogWrite, digitalRead, etc.  The pins as accessible via Firmata
> protocol usually correspond to the pins as implemented by Arduino, but in
> some cases special mapping is needed.  Not all pins support all features,
> and Firmata needs to know which do.  Arduino also lacks some important
> information Firmata needs.  The hardware abstraction layer provides all
> this, so (hopefully) StandardFirmata can be easily ported to any new boards
> which work with Arduino.


I had a brief look at boards.h, it's more clear now :)

Just some comments: TOTAL_ANALOG_PINS must not exceed 16, but some
microcontrollers (eg.many PIC) can have way more than 16. Why is there such
limitation ?


>
>
>
>  Since I'm implementing Firmata for Microchip PIC (using Jalv2 language),
>> this sounds interesting to me
>>
>
> As a practical matter, StandardFirmata and the Firmata library are written
> in C++, built on top of the Arduino system, which is really just C++
> libraries as far as we're concerned.  If you're working in Jalv2, a
> completely different language, much of this may not be very useful for you.
>  It may end up being simpler to just reimplement the Firmata protocol,
> perhaps specific to only your target hardware, or maybe with a similar
> abstraction layer?
>

I used Arduino/Firmata code to convert it to Jalv2, and noticed some hard
coded logic related to pins. When converting, I tried separate generic and
specific stuff, this could lead to a kind of very "light" hardware
abstraction layer too...

    http://code.google.com/p/jaluino/source/browse/trunk/lib/firmata.jal
+ pin mapping:

http://code.google.com/p/jaluino/source/browse/trunk/lib/jaluino_medium_pinmap.jal



>  Could someone enlighten me ?
>>
>
> I hope this helped.  :-)
>

It did, thanks !

cheers,
Seb