[PD-dev] small gizmos

Tom Schouten doelie at zzz.kotnet.org
Mon Aug 23 19:48:15 CEST 2004


hi all,

just polling for reactions.

i noticed 2 things:
* pd and forth mix very well
* forth and microcontrollers mix very well

i had this idea of writing a forth for a picmicro, which consists of 2
linked forths, one running on the host, one on the target. which
effectively enables you to have a 'shell' on a microcontroller over a
serial line, or midi, or another bus.

it's not working yet, mostly because i just was too scared to apply power
to that picmicro circuit, but the start of the idea is on my zwizwa site.
the design is mostly ready, the implementation sucks and needs to be
redone.

this forth (badnop) is actually the one that made me write mole, and mole,
which is no more than a geek toy atm, eventually lead to a better pf.
it took me a while to get right. once you start writing forths..

now, i was thinking. why not just make mole to be the host forth, choose
an architecture, and start develloping some standard microcontroller
protocol for pd, so you could eventually just abstract (a program running
on) a microcontroller as a pd object.

i'm currently using the picmicro 18f452 as a target chip, which is not
extremely fast and cheap and all, but has an instruction set that maps
very well to forth, so i can compile directly to binary code. no need for
closed source tools etc.. (generated code is peephole-optimized and
actually works in the simulator :) i'd like to eventually design it that
the target does not matter, but i'd like to get the rest working first.

now, i know this has a lot of 'forth' in it, but would anyone be remotely
interested in helping to design/implement it further? it's not too hard
to actually do, most of it already works except the hardware part, and
might be pretty useful.

the thing for me to find out is how 'standard' i can make the way to plug
this into pd. i can go on a solo tour and say 'just use mole', but i'd
like to somehow take this to a higher level. maybe writing some basic
library to run on a micro.

any idea would be welcome.

cheers
tom







More information about the Pd-dev mailing list