Strange problem.

[rbivins]

URC-7800 with the VCR 0618 code that I downloaded from the files section (with no modificatio). It is the Tivo Master File (https://www.hifi-remote.com/forums/dload ... ile_id=791)

The Remote is a new one that I just bought from Rob. When I try to use this upgrade code I noticed that it wasn't working. Quite by accident, I noticed that it worked fine if the remote is pointed at an oblique angle to the Tivo (it is a Hughes DirecTiVo SD-DVR40). The protocol ID is 0111. Pointed directly at the TiVo the remote doesn't work (we'll call that 90 degrees). Pointed at anything less than 60 degrees and it works fine.

If I learn all the functions from the original remote, the remote works fine regardless of the angle. The angle thing only happens when I use the upgrade code.

Anyone have any idea what this is about?

Here is my IR file: http://www.bivinsgroup.org/files/Bivins.ir

Here is my rdmu file: http://www.bivinsgroup.org/files/Tivo_Master_File.rmdu

Here is the file I used to make the upgrade using that java applet: http://www.bivinsgroup.org/files/Tivo_Master_File.txt

Any help would be greatly appreciated.

--Robert

[The Robman]

Your subject line is accurate, this is weird. I have no idea.

[johnsfine]

If I learn all the functions from the original remote, the remote works fine regardless of the angle. The angle thing only happens when I use the upgrade code.

I undeleted the deleted learned signals from the .ir file you posted. I notice they're all at a slightly higher frequency than the upgrade. I assume the upgrade is correct but...

One theory for the problem is that the 7800's IR signal is too strong. A slightly wrong frequency might compensate for that. That idea is combining two long-shot theories, so I won't say it's likely. But I can't think of anything that is likely.

If you want to raise the frequency a little (and lower the duty cycle) for that upgrade, change the first two bytes of the protocol upgrade from "43 8D" to "3D 92". That's my best guess of what the learned signals would be using.

If you want to confirm that the 7800's signal is too strong, you could tape a sheet or two of paper in front of the Tivo's IR receiver and then try the 7800. IR signals go through paper, but should be reduced in strength.

[rbivins]

If you want to raise the frequency a little (and lower the duty cycle) for that upgrade, change the first two bytes of the protocol upgrade from "43 8D" to "3D 92". That's my best guess of what the learned signals would be using.

If you want to confirm that the 7800's signal is too strong, you could tape a sheet or two of paper in front of the Tivo's IR receiver and then try the 7800. IR signals go through paper, but should be reduced in strength.

I will try that forthwith. Great idea. I have a feeling that you might be correct. I don't have the problem when I use the remote while in the other room (using a remote extender from radio shack).

I think I'll give the frequency thing a try, as well. I will post my findings.

--Robert

[rbivins]

Putting a piece of paper in font of the IR receiver works. Kinda tacky looking, and it does reduce the effectiveness of the IR extender. What a dilima...

The URC-7800 does have two diodes, though. Which probably explains why it works when at an angle. Upon further testing, only one diode is pointed at the TiVo at that angle.

The "brightness" of this remote has always been one of my favorite features about it. You can control many devices from other rooms with it anyway (as long as the doors are open and there aren't any obstructions, of course).

I will see if the frequency change works as well. BTW, which duty cycle am I decreasing? Am I shortening the life of the remote with this change?

--Robert

[rbivins]

Frequency change works as well.

Which solution should I use? Don't know if I want to risk harming my remote...

--Robert

[johnsfine]

BTW, which duty cycle am I decreasing? Am I shortening the life of the remote with this change?

It is the duty cycle of the IR LED. Increasing that might harm the remote. Decreasing it can't harm the remote in any way. Decreasing duty cycle trivially improves the battery life. Under other conditions decreasing duty cycle reduces the distance over which the remote is effective.

So use the frequency/duty cycle change, not the piece of paper. The paper was just intended as an experiment to determine whether the signal was too strong for the device.

[rbivins]

Oh. Interesting use of the term duty cycle. With copiers, duty cycle refers to the number of times per unit of time that a particular part must be changed and therefore the cost per unit for each copy made and the ultimate lifespan of the copier. Higher duty cycles (measured in pages printed) in that case are better (cheaper, longer lasting). At least that's why I remember when my company was purchasing a new high volume copier.

Thanks for the fix.

--Robert

[johnsfine]

It's the reverse side of the same concept. Duty cycle of use vs. Duty cycle of capacity.

In engineering, duty cycle refers to some measure of fractional use. You might loosely describe the duty cycle of a copier by the number of pages you print per day. A higher Duty cycle means you're printing more and will wear it out sooner.

You were looking at a spin-off of that meaning. The duty cycle capacity of a copier might be loosely defined as the maximum duty cycle (meaning use) at which that copier won't wear out unacceptable early.

In a remote the "duty cycle" of the IR LED is the fraction of time during which there is current flowing through that LED. It is actually significant on a number of different time scales. Those two numbers in the protocol control the duty cycle at the finest granularity of timing. At coarser granularity the duty cycle must be (and is) a fraction of whatever it is at the finest granularity.

So lowering the duty cycle is like using the copier for fewer pages per day than you planned on when you bought it. It isn't like replacing the copier with one capable of fewer pages per day.

[rbivins]

I got you. We're comparing two different things. When comparing the duty cycles of two different objects which can perform different unit/amounts of work in some fixed time unit (day), then the one with the longer duty cycle could last longer and might be more economical in the long run, then the one with the shorter duty cycle. This assumption presupposes that your planned usage of both would remain fixed (logically). Whereas if you adjust the duty cycle of one particular object (fixed capacity, fixed rate, fixed time interval) then you are either prolonging or shortening its ultimate lifespan (inversely, it would seem).

Algebraically, it makes sense. Of course, English miffs it all up, with its double-meanings, innuendo and inflections.

Thanks for that clarification.

--Robert
PS: In the meantime, the remote is working like a charm.

[rbivins]

BTW, just curious, does the fact that the lifespan of the diode is increasing mean that the remote is simply speeding up the signal to achieve the higher frequency (thereby shortening the amount of time it is flashing)? How does the increase amount of energy that passes through the diode affect its lifespan (higher frequency radiation requires and possesses more energy)?

Don't mind longer diode life and longer battery life. I see those as positive side effects that I can live with.

[rbivins]

OK, new problem. The VPT isn't working correctly now that I've applied this upgrade. It doesn't work for the aforementioned Tivo code, but for every other code on the remote it works fine. I also cannot learn the codes from my TV on that code (VCR 0618). I can store those keys (Vol+, Vol-, and Mute from my TV) to any other device except that device that was upgraded. All the remote does is briefly flash (so quick you really can almost NOT see it).

This behavior is the same if I learn it while on the Tivo device, or if I save it to another device and use IR.exe to change the mapping of those learned codes.

The links to the files are all the same as my original post, the Bivins.ir file has been updated to reflect the changes that I've attempted. You'll notice that I have two version of the Tivo device, one that is unchanged and one with those three buttons unassigned. Neither configuration plays nice with the VPT, and neither one will transmit the learned codes from my TV's remote (or any other for that matter).

Thanks,
--Robert

[johnsfine]

the remote is simply speeding up the signal to achieve the higher frequency (thereby shortening the amount of time it is flashing)? How does the increase amount of energy that passes through the diode affect its lifespan (higher frequency radiation requires and possesses more energy)?

It is the frequency of the modulation, not the frequency of the IR radiation itself. So it isn't more energy.

Don't mind longer diode life and longer battery life.

It isn't longer by a detectable amount. We're talking about a very tiny change. I was just reassuring you about the direction of the change.

The VPT isn't working correctly now that I've applied this upgrade.

That's normal. VPT doesn't work unless the device type of the upgrade is the same as the default device type of the device button you assign it to. You can change the device type of the upgrade in KM then reinstall the upgrade into IR (and delete the old one from IR).

The right device type will fix VPT, but changing device type in KM may change the number of KeyMoves needed to support that upgrade. Most of us are short of KeyMove memory, so if the number of KeyMoves increases by more than 3, you are better off fixing VPT with three KeyMoves rather than changing the upgrade type.

I also cannot learn the codes from my TV on that code

Again normal. Older remotes don't allow both upgrades and learned signals in the same device mode.

You can look up the EFC numbers of the vol commands for your TV, then assign them as KeyMoves using IR.EXE (or assign them as KeyMoves using the 994 command on the remote and you won't need to look up the EFC numbers). That is only needed if you decide not to change the device type of the upgrade (to match the default device type of the device button).

[rbivins]

You can look up the EFC numbers of the vol commands for your TV, then assign them as KeyMoves using IR.EXE (or assign them as KeyMoves using the 994 command on the remote and you won't need to look up the EFC numbers). That is only needed if you decide not to change the device type of the upgrade (to match the default device type of the device button).

Code 994 works like a charm. You are the man. Now, I can get the wife off my back. She HATES that extra keystroke!

BTW, I use rechargeable NiMH batteries in my remotes. They can theoretically be recharged 1000 times. And, they last longer on one charge than an alkaline battery (at least in my very unscientific tests). So whatever minute improvement in life I see is then multiplied by 1000. Might be enough to be significant.

*shrug*

Thanks for the info and help.

[johnsfine]

Code 994 works like a charm.

After you do programming like that on the remote itself, remember to do a download back to IR.exe and save the file, so you have both a backup and a starting point for any future change you want to make in IR.