Hamlib keying

[Christoph Berg]

Hi,

I've been poking around with adding support for CW keying via Hamlib
to Tlf. I have it somewhat working. :)

https://github.com/df7cb/tlf/tree/hamlib-cw

Basically the status is:

    Working:
    * Hamlib keyer is activated by HAMLIB_KEYER keyword
    * CW sending works
    * setting CW speed works
    * reading CW speed from rig (when adjusted via knob or menu) works

    TODO:
    * rig CW support is detected by rig type, but should be queried from the
      actual rig (makes a difference with rigctld)
    * aborting CW doesn't work yet
    * less than ideal interaction with the cw speed stepping in Tlf
    * no other keyer commands (pitch etc) supported yet

I've been reading through

https://www.mail-archive.com/tlf-devel@nongnu.org/msg02341.html

and I don't have a solution for implementing in-message speed changes
yet (+++TEST---), but if it turns out not to be feasible, I'd think
having the general feature would still be nice - less cables, and the
ability to turn the keyer speed knob on my IC7610 and having Tlf pick
that up is already nice.

One problem I have is the baroque handing of CW speed in Tlf:

#define CW_SPEEDS       "06121416182022242628303234363840424446485060"
                        /*< speed string with 2 chars each (in WPM) */

What's the reasoning behind that? Storing the desired WPM in a plain
integer would be much cleaner, and PgUp/PgDn could still adjust the
speed in 2-wpm steps instead of doing string mangling all the time.

Christoph DF7CB