SparkFun Forums

[ex1199]

I have a Philips soundbar, model number CSS2123B/F7, and it is great, but it is not without its faults. One of my biggest complaints, is that it is very difficult to tell if it is turned on because there is only a small light on top of the soundbar that turns on and if it is positioned above your eye level, you cannot see the light. Also, this model allows you to adjust volume, bass, and treble levels, but there is no way to tell what the level is. In other words, you just keep pressing the button on the remote and the levels increase/decrease, but it is very annoying because if someone changes it, I have to keep adjusting it until I get it where I want. It would be much more convenient to be able to know a number, so that I can always have the levels set to the same.

I am currently in college studying electrical engineering, and I have a basic knowledge of all of this, but I love projects. That being said, I have given this project some thought, and I have come up with an approach, I am not sure if this is very feasible though.
Use some kind IF receiver to receive the signals from the remote. Then use some SSD LEDs to display what the current level is, and increment/decrement the number depending on the signal received. I would also like an LED to light up when the soundbar is turned on.
What parts would I need? How difficult will this project be?

Thanks so much!!

[Mee_n_Mac]

How does your receiver "know" what the level setting inside the soundbar is ? Seems to me that you need a new remote that talks to your receiver which then relays the commands to the soundbar. You sync them up at some setting for all the controls and hope they don't get out of sync (due to the soundbar not responding to some relayed command).

[ex1199]

Mee_n_Mac,
I may be misunderstanding you, but I do not have a receiver. My soundbar connects directly to the tv.

[Mee_n_Mac]

Mee_n_Mac,
I may be misunderstanding you, but I do not have a receiver. My soundbar connects directly to the tv.

and I have come up with an approach, I am not sure if this is very feasible though.
Use some kind IF receiver to receive the signals from the remote.

[ex1199]

Oh, I see what you were saying, sorry about that. To be honest, my plan was to sync them up at the beginning and hope they don't get out of sync (as you mentioned), but I realize that is not the most practical, as there is a lot of room for them to get out of sync. Regarding your suggestion of using a remote to control the receiver and then relay the command to the soundbar, how would I modify the soundbar to accept signals from the receiver? How feasible is that?

[Mee_n_Mac]

how would I modify the soundbar to accept signals from the receiver? How feasible is that?

I wouldn't change the soundbar at all. I'd have your "device" be able to send the same signals as the soundbar remote. I'd use a different remote to talk to your "device", so the only commands to the soundbar come from the "device".

[ex1199]

Oh I see what you are saying now. Can you show me what components I would need for that?
Would this work?
https://www.sparkfun.com/products/241

[Mee_n_Mac]

You got the cart waaaay out in front of the horse. First decide what you want this to do, make a specific list. Then begin to figure out how those might be accomplished. Is the soundbar remote RF or IR ? Do you want the new remote to RF or IR ? Do you know how the existing remote works, the details like it's wavelength, modulation frequency, command protocol ? If not you need to find them out or come up with a plan on how to measure them. Do you want to use an existing remote to talk to your device or make your own ? Same questions as before apply. Do you know how to make a "learning" remote ? Sounds like you may have to. About the only part you might be looking for is the display. What info is going to be on it ? All the time, staring you in the face ? From how far away and at what angles must it be seen ? In bright daylight or/and in the dark ?

From your question above I will guess you need to learn more about how IR remotes work.
http://en.wikipedia.org/wiki/Consumer_IR
http://en.wikipedia.org/wiki/Remote_control
https://www.sparkfun.com/products/8554
https://www.sparkfun.com/products/10266
https://www.sparkfun.com/tutorials/282

Lots of questions to be asked and answered before buying parts ... if you want this to work.

[ex1199]

Wow, I didn't realize this project was this in-depth! As you can tell, I am very new to all of this and I am only in my 2nd year of college, regardless, I am very willing to learn about all of this. I will start reading all of this soon, and I will get back to you when I finish reading all of this and I can answer your questions! Thank you so much for all of your help thus far, I really appreciate it!

[ex1199]

I have read over the sites you listed, and I definitely have a better understanding of how IR signals work. From what I can see, my soundbar remote is IR. My original thoughts were to use the soundbar remote and have the device receive signals from the soundbar remote. I am not sure if that is going to be possible, or if it will be feasible. I do not know what the wavelength, modulation frequency, or command protocol are for the remote, and I am not sure how to measure them. Do you have any suggestions? Can you explain to me what a "learning" remote is? On the display, I want to display 3 different numbers, namely the volume, the bass level, and the treble level. I only want it to be on when the soundbar is on.

[Mee_n_Mac]

My 1'st thought was to make the IR you use to control your box very different from the existing remote so if the soundbar sees it, it won't react and get out of sync. So your box is both an IR repeater and translator. Perhaps there's a remote you like that can be the new remote ?

Alternately (if possible ?) block the soundbars IR sensor and have your box be just a repeater/"blaster". Use the existing remote at the risk of getting de-sync'ed due to an accidental reception.

I think all the IR remotes use light in the 920-950 nm waveband and any IR LED in that range can be made to work. As you should now know that LED is turned on/off (100 % AM) with a duty cycle btw 33 % and 50%. The DC isn't all that critical but the mod frequency (32 - 40+ kHz) can be. If you can't Google to find it, you should measure it for both remotes. While an O-scope would be nice, I'd think a simple logic analyzer would also work. If you can't steal either, that's OK 'cuz what I think you'll need to do the job can also be used as test equipment.

So how's this all going to work ? A concept is you use a different remote or somehow block reception by the soundbar. You send commands to the box, it receives and decodes the IR stream and then does at least 2 things. It recodes (if needed) the command and modulates it's IR LED to send a stream to the soundbar in it's protocol. It also keeps track of the command, updates some memory component, and displays (perhaps only for a moment) the new parameter setting. Perhaps the box does other things, like dim the display vs the sensed ambient light level or some other useful feature.

While there may be other ways to do all these functions, using a microcontroller (MCU) will be the simplest IMO. Time to learn some programming ! The tasks are well within the capabilities of low level MCUs like an 8 bit PIC or ATMega. Your system could be as simple as the right IR receiver (as I linked too), the MCU (and it's support stuff, caps, xtal, etc) and the IR LED ... and power supply of some sort, perhaps some buttons for non-IR interfacing, sensor for ambient light, etc, etc.

The MCU can be used w/the simple IR sensor you linked to, to measure the mod freq and DC. Then you can pick the correct receiver and use that to decode the protocols used. Or just record the bits and timing for the commands used.
Again Google is your friend.
http://learn.adafruit.com/ir-sensor
http://www.brainlinksystem.com/how-deco ... red-remote
http://www.adafruit.com/blog/2013/07/29 ... l-decoder/
http://tech.cyborg5.com/irlib/
http://www.remotecentral.com/features/irtips.htm (GOOD PLACE TO FIND PROTOCOLS)

The choice of MCU is up to you, both PICs and (these-days) Arduino's have been used and there's all manner of info on the WWW. One thing to consider before an MCU is the display as that may drive your MCU choice (# of I/O pins needed, communication protocol to display, etc). You may find it easier and worth the $30 to get a "dev" (development) MCU board, use that and a breadboard to get everything working ... and then either repackage the same or buy smaller, more purpose built and packaged components or even make your own PCB to put in the final box.

http://en.wikipedia.org/wiki/Universal_ ... ng_remotes
http://en.wikipedia.org/wiki/Infrared_blaster

[Mee_n_Mac]

BTW if you wanted to make your own IR remote (or perhaps hack the existing one) another concept would be to combine the box into the remote. That way there's no added IR receiver. The remote keeps track of all the button pushes and displays the settings. It's sync'ed, just like the box, at some point, but because the IR stream could be blocked or otherwise missed by the soundbar, I judge this idea more likely to become de-sync'ed than the other.

Still, worth a thought ...


And it might, maybe (don't hold your breath) be possible to go inside the soundbar and pickoff the digital output of it's receiver, decode the bitstream, and sync and keep track of the received commands (using just an added MCU and some display). Due to the highly integrated nature of today's electronics, I hold little hope that this is possible but ...

[ex1199]

Thanks so much for all of the information and the help! This has really helped me a lot. I have a lot of stuff going on right now, so I am going to have to put this project on hold for a little while, but I am certainly not abandoning it! I think your first suggestion, using a different IR remote to send signals to the box, then relay another signal to the soundbar.

Thanks again!