Andrew Morris decided the usual wireless volume controls don’t 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 doesn’t 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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One builder, using his volume control in a commercial setting had trouble from spontaneous volume changes. I made a change that fixed the problem, but slowed down the response of the volume control. While developing another Gadget Freak project, I revisited the remote control system and saw something I missed before. Using this new information, I rewrote my receiver decoder software to greatly improve speed and noise immunity.
If you don't have the means to program a PIC yourself, give me your mailing address and the "channel" your remote is on, and I will send you a PIC programmed with the updated software. If your "channel" is something other than A B C or D, then I will need to know which jumpers are cut in the transmitter or the discarded receiver unit. If you can program a PIC yourself, tell me so and I will email you the updated software.
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.
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.
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.
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.
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).
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.
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