Andrew Morris decided the usual wireless volume controls donít offer enough functionality, so he created the ultimate volume control that connects between a computer or MP3 player and an amplified speaker system.
Volume can be controlled up to 50 feet away and through walls. It doesnít require line-of-sight, and you can set a default setting for your favorite level. You can also adjust multiple volume controls in the sound system. Morris is now setting the gadget loose on the world, hoping readers will try it out and give him feedback for improvements.
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Sounds like he might have a captive audience for this for parents who want to control the volume of their teens' music or Xbox games from behind the scenes. Might help avoid some of the daily conflict. Sign me up!
I think the most interesting function of this gadget is that it remembers your favorite volume level. I am always fussing with my iPod and speakers trying to get the right volume so this would be great.
On of the interesting things about this device is that it doesnt' require line of sight and it goes through walls. With all of the changes we've seen in consumer electronics, the one device that hasn't changed substantially since the 70s is the remote.
You're right, Jack. We're all so used to line-of-sight -- and nobody walking through that line. Seems like the whole world of remotes could be revampped on this principle. Our remotes -- which are in everyone's home by the armful -- still operate on 70s technology.
Contact me for a minor bug fix to the remote decoder PIC ASM code in Gadget Freak Case # 192, the remote volume control. The BITST subroutine was rewritten for better noise immunity. Alternatively, you can get the updated BITST subroutine from the remote fan control in Gadget Freak Case #198. Don't use the whole program, as it will slow down the volume control response.
Alternate sources for the remote control to be hacked up:
Home Depot Westek Model # RFK306LC Store SKU # 567861
Home Depot (Christmas season only) Home Accents Holiday Model # RC-009A-1 Store SKU # 202620 (Same as above units, but has two outlets).
Lowe's SKU # 0357410 (Christmas season only) It is the same as the Home Depot Christmas version, but has a smaller remote, that is electrically identical to the remote used in this gadget.
Both seasonal remote control systems will work in this project, and both cost $10.
Thank you, yes, I have been thinking about asking you about programmed PICs. I am currently trying to source all the parts without paying too much shipping. If that is not too much hassle I may get a pickit2 and program it myself. If it's big hassle I may ask you for PICs to save some time. I'll let you know via email.
It has to be an amplified speaker system connected to the TV (i.e. line-level or headphone-level signals). The volume control cannot control the speakers directly. If it is a line-level signal, delete the 100 ohm resistors at the input.
I built two remote volume controls and one of them is connected to a TV volume regulator, which has a line-level output. If the remote volume control is being connected to a headphone jack, the 100 ohm resistors are needed to allow the TV, or whatever, to sense the load and switch its internal speakers off. Most electronics nowadays use electronic means to detect a load on the headphone jack and switch off the built-in speakers. Gone are the days of having a mechanical switch in the headphone jack.
No, It's not a Hammond enclosure. It's Radio Shack 270-1803. The link I sent you earlier has the part numbers and sources of parts not available at Allied. Since Allied sponsors this blog, they don't like people to mention the sources of parts they don't sell. That's why I sent you to my YouTube page.
The volume control has an auxiliary output for an optional audio switch to turn a subwoofer or audio system on and off with the incoming signal. If you are not going to use that, you can delete R2, R3, R8, D1 and D2. Add a wire in place of the diodes (between U4 pins 1 and 2).
A reader wanted to use a different remote control system with greater range for outdoor use. I redesigned the pot controller chip to accomodate two momentary inputs (UP and DN). I also rewrote the remote receiver code to produce two momentary outputs, originally to test the pot controller. My email address is in the article. Please email me if you would like a copy of this code or preprogrammed chips.
One of my readers has designed a PCB (printed circuit board) for my gadget. He designed it to accomodate multiple configurations. That means what you do with the extra op-amp. For example, he uses it as a third channel for his high-end subwoofer. If you want a PCB, email me and I'll hook you up to him. I'm not making anything off of this project. I just want people to enjoy my gadget.
One reader made one of my volume controls and had a problem with spontaneous volume changes. He used it at his gym, where it was located in a utility closet with a WiFi router and other network hardware. While I've not had such problems with my units, I sent him a new PIC with a routine that verifies a valid data word twice before taking action. This solved his problem, but slowed down how fast he could click the volume up and down. I've since made a change to the program that reduces the lag time by 100 to 200mS, which was a big help. All versions of my decoder software now have this fix.
I recently discovered that the Chinese factory that makes these remote controls also makes a 3-pack version with a 6-button transmitter and 3 receivers. They are completely compatible with the units I've been using. I'm currently working with a person who wants to use one of the extra channels to turn his system on and off and another channel to switch signal inputs. I have already written code to decode the other transmitter channels. Please email me if you want further information.
Whether you're a designer, gamer, or just like to have a busy desktop, two monitors (or TVs) is always better than one. Gadget Freak shows you how to build an entertainment center that can hold two 70-inch TVs.
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