Author Topic: Help me choose a reciever IR vs RS-232  (Read 1188 times)

krys

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Help me choose a reciever IR vs RS-232
« on: November 20, 2008, 04:40:34 pm »
Hey topic says most of it, I am gonna throw down on a new AV reciever. I currently own a sony that does the standard Dolby 5.1 etc but it doesnt do HDMI inputs and it only has 1 optical input (i currently have a manual switch for my optical inputs). I will be using three input devices in this room.
    1.Cable box- HDMI connection sound/audio for HD cable
    2.Xbox360- component connection for video/ optical connection for audio for gaming
    3.MD for LMCE- VGA for video/ optical to receiver for sound
I will need the following outputs also.
    1. 5.1 speaker outputs (or something else like 7.x that is compatible with 5.1)
    2. additional speaker outputs for a different sound zone
    3. HDMI output to TV

So LMCE can control all of these inputs I would like everything routed through the receiver which will be controlled by IR or RS-232, this is the main dilemma. Is RS-232 worth the extra money or is IR just as capable? It seems like the cheapest receiver that has the things I need with RS-232 costs twice as much. Also I want the receiver HDMI out to be the only cable going to the TV (except the VGA).

tschak909

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Re: Help me choose a reciever IR vs RS-232
« Reply #1 on: November 20, 2008, 05:20:57 pm »
By Nature, IR can't send data back to the system, the system can only transmit.

This means that if devices in IR change their state, it will be unknown to the rest of the system.

Also, it is often a hit or miss if an IR device supports discrete codes for things like switching on/off power or switching between inputs. This means, that when the system's router reloads, any internal notions of a device's state will be forgotten.

An example,

Say you have a Westinghouse SK-26H240S TV. This TV is IR, and it only has toggle power on/off codes.

TV is on, LinuxMCE thinks TV is on because it turned the TV on when you tapped an orbiter or remote.

Now, for some reason, router gets reloaded.. This could be a system reboot, or a quick reload router, whatever. TV is still on.

LinuxMCE resets its internal state. It thinks all the A/V devices are off.

You tap a remote or orbiter.

LinuxMCE thinks, "Oh! Need to turn on the TV."

so it sends a TOGGLE POWER command to the TV via IR.

TV, still on, recieves the toggle... and guess what? it turns off.


Little hiccups like this.. Which, really aren't our fault, but are due to the nature of how IR works.

With RS-232, there are discrete codes for every command, and furthermore, the state of the system can be reported back. So if you turn on the TV or amp, and switch inputs on the amp, etc, if the amp returns this information and the device template is configured to parse it, LinuxMCE will react to it (oh, he flipped to the VCR input, select the VCR media button on the orbiter and turn on the TV etc.)

This is all due to the intelligent nature of LinuxMCE's pipes system.

However for this to work, the device driver needs to be written for a given amplifier, and all of the inputs and outputs need to be specified in detail, so that LinuxMCE can make intelligent decisions on what commands to send to achieve a desired result.

Of all of the device templates, the one for the Yamaha RX-Vxx00 templates is the most complete. It has full bidirectional control in the template, and all of its inputs are defined correctly, so LinuxMCE can switch between them nicely. Since an amplifier is not a high speed device, the template's commands can be written entirely in ruby.

Hopefully, this makes things a bit more clear,
-Thom

krys

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Re: Help me choose a reciever IR vs RS-232
« Reply #2 on: November 20, 2008, 06:18:34 pm »
ouch, those Yamaha RX-Vxx00 series are all over $1200!!!  :o

edit** I just found a Yamaha RX-V1800 for $690, thats more like it

also a Rx-v1700 series for just under $500, I was worried there for a bit but this is about what I was looking to spend.
« Last Edit: November 20, 2008, 06:40:08 pm by krys »

cirion

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Re: Help me choose a reciever IR vs RS-232
« Reply #3 on: November 20, 2008, 10:32:44 pm »
There are ways to fake discrete codes on TV's like that... First I would always check remotecentral.com to see if they actually have dirscrete codes for power on/off.

But a TV usually turns on with several buttons, not only the power toggle button.
For example if the TV is off, you can turn it on by pressing CH+ on the remote to turn it on.
This button is then a ON button that never turns off the TV.

You can then make a macro for ON or OFF.
ON would be like this:
CH+

OFF would be like this:
CH+
Pause
Power

tschak909

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Re: Help me choose a reciever IR vs RS-232
« Reply #4 on: November 20, 2008, 11:30:45 pm »
yuck.

-Thom

eNoodle

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Re: Help me choose a reciever IR vs RS-232
« Reply #5 on: November 21, 2008, 09:22:45 am »
@krys

I've a RX-V1700 running. It has 2x HDMI and a lot of digital and analog audio/video input. However, the RX-V1x00 template missed the inputs for the two other audiozones, but adding them to the existing template or building some new templates isn't a problem. The receiver is controlled perfectly by LinuxMCE. You can have a look at my wiki page to see, how I got this running.

http://wiki.linuxmce.org/index.php/User:ENoodle

I used the RX-V1x00 because it was able to control the input (MD or PS3) using the receiver. The TV I'm using doesn't have discrete codes, so input selection was solved this way. Power toggle is still a problem, but using other buttons and building macros wasn't the way to go for me. To solve power toggle issue I'm prefering something like a TV current sensor. There is one available from Xantech, it monitors the current and the return value can be used to determine, if the TV is on or off. Problem here is, that the Xantech doesn't look easy to integrate and isn't available in europe. Currently I'm trying to get a custom build solution for this having a norm power plug and a serial connection. The serial (RS232 or USB) connection can then be used to get the state of the device and set the states within LinuxMCE.

eNoodle

cirion

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Re: Help me choose a reciever IR vs RS-232
« Reply #6 on: November 21, 2008, 02:36:34 pm »
yuck.

-Thom
I know IR sucks, but if that's what you have, and don't want to pay for a real solution....

krys

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Re: Help me choose a reciever IR vs RS-232
« Reply #7 on: November 21, 2008, 03:21:16 pm »
@krys

I've a RX-V1700 running. It has 2x HDMI and a lot of digital and analog audio/video input. However, the RX-V1x00 template missed the inputs for the two other audiozones, but adding them to the existing template or building some new templates isn't a problem. The receiver is controlled perfectly by LinuxMCE. You can have a look at my wiki page to see, how I got this running.

http://wiki.linuxmce.org/index.php/User:ENoodle

I used the RX-V1x00 because it was able to control the input (MD or PS3) using the receiver. The TV I'm using doesn't have discrete codes, so input selection was solved this way. Power toggle is still a problem, but using other buttons and building macros wasn't the way to go for me. To solve power toggle issue I'm prefering something like a TV current sensor. There is one available from Xantech, it monitors the current and the return value can be used to determine, if the TV is on or off. Problem here is, that the Xantech doesn't look easy to integrate and isn't available in europe. Currently I'm trying to get a custom build solution for this having a norm power plug and a serial connection. The serial (RS232 or USB) connection can then be used to get the state of the device and set the states within LinuxMCE.

eNoodle

Thanks Noodle that review makes me feel comfortable enough to purchase this product.