Sounds cool. There's a good externals-howto available at:

http://pd.iem.at/externals-HOWTO/

Arf, it's the one I learned the PD API with... I think I should have pushed my reading a little deeper than the examples :) Reading references is always good...

[pack] likes to output the selector "list", so if you want to feed [pack]'s output to your object, you need to do something like:

class_addlist(servo_class, servo_list);

in servo_setup() and write a method:

void servo_list(t_servo *x, t_symbol *sel, int argc, t_atom *argv);

... where you can just do some type-checking and call "servo_go()"

It works great! Now I can go to sleep!

I've never tried it, but you might be able to do:

class_addmethod(servo_class, (t_method)servo_go, &s_list, A_DEFFLOAT, A_DEFFLOAT, 0);

in servo_setup(), and pass the object pairs of floats:

[42\ [24\ | | [pack 0 0] | [servo ...]

... providing that every [pack]ed message is interpreted as a "go" message...

I tried this before I knew about class_addlist. It doesn't work. Also tried getsym("list") which, I believe, is the same as &s_list.

Your other very easy solution works, of course. How could I have missed it? Ho! I'm tired too :)

Well, if someone is interested in this little device, I can put up a web page decribing it.

Thanks to all and especialy Bryan, Julien