[Hamlib-developer] easycomm protocol

[Allen, W. <wa...@it...>]

So rather than trying to add a Galil controller to the Hamlib backend, I've been tinkering with writing my code to communicate with hamlib via a psuedo terminal. I was thinking the easycomm 2 protocol looked like it was pretty well documented so I'd just need to have my C++ code interpret the easycomm commands and instruct the Galil controller to respond appropriately.

The Linux null-modem emulator <http://sourceforge.net/projects/tty0tty/> seems to work pretty well for setting up the pseudo terminal pairs, and I've cobbled together a program to read and write on the serial port. If I run the null modem program to generate the pseudo terminal pair /dev/pts/23 <=> /dev/pts/24 I can then run rotctl as:

rotctl -vvvvv -m202 -r /dev/pts/23

and run my program connected to /dev/pts/24. This all seems to be fine. If I use the set position command "P" in rotctl, my program successfully gets the command string, an example being:

AZ45.0 EL78.0 UP000 XXX DN000 XXX

What I'm not finding documentation on is what the protocol should be for the get position command "p". My program receives a single exclamation point "!", and that is consistent with what rotctl is reporting that it sent. OK, that's easy enough to decode, but what do I send back? I've tried just replying with a string like what rotctl sends to the rotator, namely:

AZ270.0 EL90.0 UP000 XXX DN000

but rotctl doesn't seem to understand that. The response is:

Rotator command: p
easycomm_rot_get_position called
write_block(): TX 1 bytes
0000 21 !
read_string(): RX 31 characters
0000 41 5a 32 37 30 2e 30 20 45 4c 39 30 2e 30 20 55 AZ270.0 EL90.0 U
0010 50 30 30 30 20 58 58 58 20 44 4e 30 30 30 20 P000 XXX DN000
easycomm_rot_get_position: unknown replay (AZ270.0 EL90.0 UP000 XXX DN000 )
get_pos: error = Command rejected by the rig
I'll go see if I can figure this out from the hamlib source code, but if it is documented somewhere that could save me some time.

- Wayde