# @sanderton, maxwells_daemon, etc.. Modify endpad to retry channel change



## harryw (Sep 4, 2002)

I have one of these NTL Pace boxes that sometimes misses a channel change. I've tried everything suggested on this site, I've even tried new IR codes grabbed from the original remote and converted to tivo format. It work most of the time (maybe 90%) but I though that by modifying the startpad section of endpad I could get tivo to try change the channel and then stop and remove the recording and change the event back to the unpadded version - this would give two chances to do a channel change (90->99% success). 

Alternatively , instead of endpad doing a startpad at all it could do "change channel" - (anyone have an idea of how to do a change channel from tcl?). Then the tivo would do the second channel change attempt when it actually started the recording -a minute later.

P.S. Endpad is great - thanks


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## b166er (Oct 24, 2003)

I don't think you can do a retry of a channel change.

Try this: (although it maybe unique to Sky)

Enter channel number 101 on the remote, watch it change to 101.
Then enter 101 again on the remote.

On my system I get a bluescreen after the second 101.

If I enter 101 again (a third time) then the channel appears again.

So a RETRY is a bad idea. You have to remember that the TiVo doesn't know whether or not it's successfully changed channel or not. It's not like it can check whether the change worked and retry if it didn't. So having a retry would ALWAYS give you this bad change behaviour.

Perhaps this blue screen behaviour is unique to Sky though, I'm not sure.


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## cwaring (Feb 12, 2002)

b166er said:


> Perhaps this blue screen behaviour is unique to Sky though, I'm not sure.


 No it's not. That's how Tivo works. I believe that the "blue screen" channel is the RF and the one that works is via the SCART; or something like that


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## GarySargent (Oct 27, 2000)

Yes but if you are simply sending IR change channels from a script, that is different to telling TiVo to change the channel (and you wouldn't get a blue screen).

However in this case I don't see sending two channel changes would be any more foolproof. The first change might work fine, then the second could send you to an incorrect channel, if one digit was sent as two for example (so say channel 113 would be sent as 1113 and you'd be on channel 111).


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## b166er (Oct 24, 2003)

GarySargent said:


> However in this case I don't see sending two channel changes would be any more foolproof. The first change might work fine, then the second could send you to an incorrect channel


Great point. The first channel change would basically be thrown away and the final result would be whatever happened on the second change. Hence back to the original posters 90% success rate. No matter how many retry attempts, it's always going to be 90%.


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## PhilG (Jan 15, 2002)

I used to have channel change problems (years and years ago) so I switched to a slower IR code for my Sky box. Now, although it changes channels s l o w l y, it's 100% accurate

Perhaps worth a try


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## Warble (Sep 2, 2002)

I miss the odd program because my Digibox doesnt get all the numbers (missed first half of Love Island last night - boy am I in trouble  ). When this happens the Digibox stays on the same channel - might be different for cable boxes but still, maybe not such a bad idea.


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## harryw (Sep 4, 2002)

With my setup (NTL Pace STB - no Sky) there's no problem sending the same channel twice, apart from the STB banner showing up again for a few seconds - a small price to pay.

I did come across a solution on this forum - originally targeted at the sky-box red-dot problem which has since gone away. The script (set of scripts) is pretty flexible and can be used to send anything to the STB based on a large number of criteria (is the tivo recording a program, for how long, from whcih source, on which channel, etc etc,)

The tcl script is call irblast and can be found in a 2004 thread "(v1.2.1) No red dots or missed channel changes".

I've installed it and hacked it to send multiple channel changes to my tivo for the first couple of minutes of a new recording. Some of the digits are getting through - many are lost. I'm going to play with delay times etc to see if I can get the retries up to the same sucess levels as the tivo's original attempts.

When I have something that works (ish) I'll post it here - irblast doesn't appear to be supported post the "red-dot problem resolution, but the author - occitan - wrote a pretty flexible tool - could be used to lots of cool things - e.g. turn the telly on for your favorite soap every evening - might be a good way to convince burlars that someones home!


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## b166er (Oct 24, 2003)

harryw said:


> I'm going to play with delay times etc to see if I can get the retries up to the same sucess levels as the tivo's original attempts.


I guess you didn't read any of the response you got in this thread. The conclusion was that it's fairly pointless trying.


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## mikerr (Jun 2, 2005)

channel change retry after 30 seconds would fix the annoying missed recordings that
telewest tvdrive does every morning:

It goes into "resting" mode (spins down HDD), and only wakes up on a keypress - which is fine, except it misses the tivo channel change if it was resting at that time.

After that its fine - but I often find early morning programmes are missed because of this...


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## cwaring (Feb 12, 2002)

To be fair, that's not really a fault with the actual TVDrive  (Although I do personally think that it 'resting' is a complete waste of time )


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## harryw (Sep 4, 2002)

@b166er

I did read the responses - as Gary said the source change problem that you mentioned won't exist as it's the tivo sending the channel change.

The problem Gary thought I would have doesn't exist either - my STB requires exactly 3 digits to change channel - it one or more digits gets lost then it stays on the old channel. So any correct channel change from the original or the repeats will be result in a correct final channel.

Other peoples STBs might have that issue of course.


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## b166er (Oct 24, 2003)

harryw said:


> I did read the responses - as Gary said the source change problem that you mentioned won't exist as it's the tivo sending the channel change. The problem Gary thought I would have doesn't exist either - my STB requires exactly 3 digits to change channel - it one or more digits gets lost then it stays on the old channel. So any correct channel change from the original or the repeats will be result in a correct final channel.


They're not the main problem though. I think it was Gary that pointed out that making a second channel change doesn't help anything at all. At the end of the day, it's the second channel change that sticks. Whether the first succeeded or failed makes no difference. It's the second one, or third one, or however many you do, that remains. The last one is the only one that counts, and that one still has only a 90% success rate.


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## GarySargent (Oct 27, 2000)

If you're always getting missed digits and the box simply times out after receiving only two without changing channels, then resending may be beneficial. However sometimes duplicate digits are sent where only one should have been sent and in those cases you aren't helping by resending.

With regards to the rest mode - TiVo can send a "wake up" IR keypress before each channel change, but the time between the wake up and channel change is small (a second or two). Also this slows down channel browsing through TiVo as channel changes take longer.


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## harryw (Sep 4, 2002)

Obviously not explaining myself very well. Here's two examples - lets say Tivo is changing from 111 to 123

Tivo sends 123 and STB "sees" 123" channel changes to 123
irblast sends 123, STB sees 13, channel stays at 123
irblast sends 123, STB sees 1, channel stays at 123

or

Tivo send 123 and STB "sees" 12 channel stays at 111
irblast sends 123, STB sees 13, channel stays at 111
irblast sends 123, STB sees 123 channel changes to 123

Does this make sense now?

I see Gary understood what I meant - posts overlapped


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## mikerr (Jun 2, 2005)

cwaring said:


> To be fair, that's not really a fault with the actual TVDrive  (Although I do personally think that it 'resting' is a complete waste of time )


 Throwing away a keypress *is*a fault... a human with a remote will just keep pressing the buttons for 10 seconds while it starts up (and get annoyed) - a tivo blindly sends the channel change once only...

E.g. press 103 first thing in a morning, and the tv drive will ignore all keypresses until you press enter. 
So you have to press OK...wait 10 seconds...then press 103.

Press 103 in the evening and it changes to channel 103, as expected.

Sorry for hijacking the thread... but I`ll probably get this installed, thanks for the pointer!


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## b166er (Oct 24, 2003)

harryw said:


> Obviously not explaining myself very well. <snip> Does this make sense now?


OK, let me re-word it to see if I really did understand...

The first change may or may not work. So it'll be in an unknown state. The second change now gets to have a go.

If the first change worked properly and the second change WORKS also, no harm.

If the first change worked properly and the second change FAILS, no problem, we're already on the first channel thanks to the successful first change.

If the first change failed, then the second change gets a chance to put that right.

Only one out of those four scenarios can result in no change and that's when both channel changes fail. In which case, the retry gave it a shot...


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## cwaring (Feb 12, 2002)

mikerr said:


> Throwing away a keypress *is*a fault...


Not really. The TVDrive is not _supposed_ to be used with a Tivo  It doesn't "throw away" any key presses when used normally; as far as I can tell anyway.

As I said, I take - and agree with - your points about resting mode. What a useless idea


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## zippy7272 (Dec 29, 2004)

If your cable box is a Pace Box, have you rebooted it recently?

The NTL Pace boxes are quite well known for having poor software in them.

Apparanlty the more channel changes that occur the worst it gets a receiving channel changes (from it's own remote). (Is TIVO like that too?)

Anyway. Reboot the PACE box every week or so, or even every day, to prove the point (or not!). Then if it works, get yourself a socket timer, to reboot it at a time when you wouldn't normally be recording something (may be at 4am etc)

Good Luck


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## harryw (Sep 4, 2002)

@b166er

Yep - that's the idea. 

It's working but for all recordings yesterday the first channel chnage worked so I'm not sure if it's effective. I did see some ghost attempts (left over channel changes from the previous recording) that were mentioned in the original thread. So I guess I'll have to try it for a few weeks to know if it it does really help.

@zippy7272

I'll keep it in my - but I do reset the box , maybe once a month, because it does seem to hang every so often. Haven't noticed any improvement after reset but then I wasn't looking for one.


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## AMc (Mar 22, 2002)

I restart my Telewest Pace box every morning with a timer. I've not missed a channel change in years. The timer costs <£10.


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## wonderboy (May 27, 2003)

I've used IRBlast to send a 2nd channel change 2 mins into every recording and it's NEVER screwed up sending the 2nd change, either only 2 digits are received (probably due to me using IR Remote) and the sky box then ignores the change.

I think it's great, even though I technically don't need the backup key I keep it running for the 2nd change.


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## steveroe (Oct 29, 2002)

AMc said:


> I restart my Telewest Pace box every morning with a timer. I've not missed a channel change in years. The timer costs <£10.


You will come home tonight to find you have missed one.



wonderboy said:


> I've used IRBlast to send a 2nd channel change 2 mins into every recording and it's NEVER screwed up sending the 2nd change, either only 2 digits are received (probably due to me using IR Remote) and the sky box then ignores the change


So will you ...

It's called sod's law


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## b166er (Oct 24, 2003)

AMc said:


> I restart my Telewest Pace box every morning with a timer. I've not missed a channel change in years. The timer costs <£10.


What type of timer do you use? I've got a couple with those revolving tumblers with pins you can put in, or the ones where you flip out a little bit of plastic (each one representing a few minutes). Trouble is they're not exactly accurate. Even looking at it, it's hard to figure out to within the nearest half hour what time it is. Do you know of any that are more accurate (a) they keep time instead of it slowly slipping in one direction, and (b) the "off-time" can be accurately set.

In the last month I've had several occasions (maybe 5 or 6 times in August) where my grundig sky digibox get in a state where it won't accept channel changes without a reboot. Forcing a reboot at 6am each day might be just what I need.

This is the one I've got that's just not accurate enough and loses (or gains) time too easily. I don't really care if the one I get has UK or Euro socket on it. It's one of those standard 8-end connectors and I've got spare cables, some with UK and some with Euro mains plugs anyway.


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## AMc (Mar 22, 2002)

I agree the squeaky creaky dial ones aren't that good. I use a digital timer so it only goes off for a minute at 6.56am.(see link in my sig for "wand position") 
That means in the worst case I would loose the last couple of minutes from a suggestion and the cable STB should be alive on channel 890 if Tivo wants to record something from CBEEBIES at 7am.
Has been working fine for several years now. The timer costs a (little) bit more than the clockwork ones but has a built in rechargeable battery so it's totally maintenance free and silent. Mine came from Robert Dyas (a hardware shop) and I think I paid £7.

(I know I'm tempting fate now - I'm away tonight but thankfully there is virtually nothing on at the moment - Tivo is full of unwatched Escape to the Country and precious little else!)


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## b166er (Oct 24, 2003)

AMc said:


> see link in my sig for "wand position"


That sure looks like what I need. Gonna have a look around tomorrow in the electrical shops


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## b166er (Oct 24, 2003)

b166er said:


> That sure looks like what I need. Gonna have a look around tomorrow in the electrical shops


Got a great deal, picked up a few of these at 5 quid each:


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## harryw (Sep 4, 2002)

After managing to fill (and thus lose) my /var partition, maybe by editing a running script - I have this working now for a week. It tries 5 or 6 times and it has managed to change channel every time. I've seen at most two failed attempts before a successful one but I'm leaving the channel change overkill in place.

The strange behaviour of changing back to the previous channel after tivo's own channel change seems to due to a delay updating the database - thus irblast gets incorrect data. So I have an extra check to skip the channel change if the new channel is the same as the old one (just for the first minute)

My code adapted from the existing ones is as follows:

# Options [default value]:
# ntlchanneldelay [2] Delay from start of recording to send channel change
#

# do your stuff for during the first 3 minutes
set ::irblast_option_ntlchanneldelay 3

set ::irblast_option_keydelay_20018 800

proc Blast_20018 {chnum isrecording wasrecording newrecording \
lastchannel newchannel elapsedmins onstandby} {

global irblast_option_ntlchanneldelay

if { $isrecording } {

# Send Channel number after N minutes into program (only for recordings)

if { $elapsedmins < $irblast_option_ntlchanneldelay } {
if { $elapsedmins == 0 } {
# don't change to previous channel in 1st minute
if { $lastchannel != $chnum } {
SendChannel $chnum
}
} else {
# try a couple of changes
SendChannel $chnum
after 15000
SendChannel $chnum

}
}
}
}


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## IainJH (Mar 27, 2002)

Hi harryw -is it possible to post the script as a "tivo executable script" so to speak -or can I just save the above as text, rename as a tcl and run it?

sorry for possibly dumb question


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## harryw (Sep 4, 2002)

Sorry for the really delayed reply Iain,

You need to install the irblast software then create an itcl file in the appropriate directory (lots of examples) -which you can copy/paste this code into. This code will only work if your IR is 20018, quite unlikely - so you'd need to adjust the name of the file, procedure and variables to match your setup.


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## jonphil (Aug 7, 2002)

mikerr said:


> channel change retry after 30 seconds would fix the annoying missed recordings that
> telewest tvdrive does every morning:
> 
> It goes into "resting" mode (spins down HDD), and only wakes up on a keypress - which is fine, except it misses the tivo channel change if it was resting at that time.
> ...


Can you not replace the IR Wands with the sender from pacelink? I don't know about Cable buy one of the Sky codes sends the 'Sky' button before the channel change to ensure it's not on a menu screen. Do any of the cable codes do something similar. I would have thought if you could get it to send a 'key' command that would wake the box it would then be ready to take the channel change?


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## mikerr (Jun 2, 2005)

Telewest boxes "freeze" on the "press ok" screen in various situations:

tuning to a channel you are not subscribed to 
the IR wands sending only two digits,
or when the TV drive is in sleep mode.

If you set "send ok after channel change" in set-top-box options on tivo, you'll /only/ miss one recording, not a week's recordings !

With the hack in this thread, you'll only miss the first 30 seconds (or not with endpad), since the first channel change(the last OK) fixes the menu, and the second change actually changes channel on the telewest box..


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