HAVA Channel Changer

[elfman]

Originally Posted by mike_15

I have had a recent event where I had my channel not catch all the digits, instead of 127 it recorded 12. I believe that it was due to my emitter being misaligned. but to satisify my curousity what do you have for the timings, ms between signals and ms between channel changes.? I wonder if I have my set poorly, or maybe they are not used.

The command that hava_channel sends to hava sends the whole channel at the same time (i.e., it sends "127" (actually 007f) not three separate commands 1-2-7). Inside of the hava itself it makes the decision about the timing between digits. I was initially surprised to discover that this was how the protocol worked but it did simplify hava_channel logic. So if you are saw "12" it probably points to a hava->set top box communication problem instead of a hava_channel->hava problem.

hava_channel only worries about timing between button presses (power, menu, select, etc) and that is configurable based on request from Jason.

I do rarely see a lost digit but attribute it to misalignment or interference between emitter and the set top box. I recently switched from dish to fiostv and got a motorola set top box (like that used with comcast). It seems to have an ir input jack in the back. Has anyone tried connecting the blaster out from hava to the ir input jack on their set top box to avoid the alignment and noise issues? I'm curious if a trip to radioshack would be worthwhile.

thx,
Elfman

[mike_15]

Thanks for explaining how the channels are sent. I will have to get some better double sided tape to hold the emitter in a good place. when I had the problem it was bumped out of place.

Originally Posted by elfman

I recently switched from dish to fiostv and got a motorola set top box (like that used with comcast). It seems to have an ir input jack in the back. Has anyone tried connecting the blaster out from hava to the ir input jack on their set top box to avoid the alignment and noise issues? I'm curious if a trip to radioshack would be worthwhile.

I did some checking on the IR port. it seems to be an output to control a VCR. which are disabled. I don't think we will have any luck using it as an input from the hava.
http://www.remotecentral.com/cgi-bin...thread.cgi?853

[Rogier]

Hi Elfman/Jason,

I tried getting hava_channel working with the TV tuner (implementing it I mean). I was wondering if one of you get give me some information on what you guys have figured out on how the packets are built up.

Hope you guys can give me some pointers.

Regards,

Rogier

[elfman]

Originally Posted by Rogier

I tried getting hava_channel working with the TV tuner (implementing it I mean). I was wondering if one of you get give me some information on what you guys have figured out on how the packets are built up.

It looks like the discussions from a year or so back on myhava.com have timed out and are all gone now. Sigh. Have you checked out the havafun sources at http://sourceforge.net/projects/havafun/ The hava_util.h hava_util_interenals.h, and hava_util.c essentially gives the details of what we've deduced about the protocol. hava_util_internals.h contains the template of the different packet types that I've had to work with for channel, button, and mpeg2 streaming. There are #defines for offsets into the packets for poking interesting values (like the device type to do remote codes for etc). We don't understand everything but channel changing and button pressing seems to have been pretty stable for sage users.

I didn't create a .doc file about the protocol... Though at this point I kindof wish I had because I got sidetracked with other stuff after a move and am just getting back to my pet project of getting hava video streaming working with mythtv.

Loosely its all UDP based. I know that the protocol has some assorted timeout/retransmit to get past UDB lossiness but I've been ignoring that part since on a home net loss is rare). Essentially you have to send hava an initial packet (init_pkt in hava_util_interenals.h] I'm not certain what all the bit fields are in it but you need to do this or hava won't talk to you. After that packet, you can send it different command packets. There is a channel setting command packet which encodes the channel as a 16bit quantity (see channel_set). There is a button pressing command packet that encodes the type of set top box as a 16bit quantity and the buttonid as a byte (see button_push). There are also what I call a start_video command packet and a continue_video command packet.

Regards,
Elfman

[Jason]

Originally Posted by elfman

It looks like the discussions from a year or so back on myhava.com have timed out and are all gone now.

Regards,
Elfman

I submitted a request to recall/repost the affected board entries...


-Jason


http://www.myhava.com/forum/viewtopic.php?f=4&t=5561

[Tuaca]

In have fun can you use learned codes? I have searched and see nothing about this ?

[elfman]

We put some patches in for this a while back after alpha3 (the default download up on sourceforge). I've not tried it myself but others sent some packet trace info to me and I hacked in some test attempts. I never got final confirmation from them that it was working so i didn't cut an alpha4. The commands are slightly different for learned remotes and only a few "named" buttons were there. (see hava_channel showlearnedbuttons).

hava_channel 192.168.1.253 Component Learned nobind Power w3 122

The "Scratch" version from post alpha3 tryme2-win.zip had this trial functionality (see http://sourceforge.net/projects/havafun/files/Scratch/).

i really need to cut a beta1 one of these days. while I've not evolved channel changing the mythtv integration is coming along well and there have been a few contributions for "recorder" support.

thx,
ElfMan