Remote Volume Controller

My sound system comprises a Denon amp from 1990, which still sounds quite good, but lacks some modern amenities like a remote control, that can be quite handy.

I searched for some time for some kind of plug-in remote volume controller, and not finding it, decided to build one that could easily be adapted to any kind of audio appliance with a reasonable sized volume knob.

I then designed a simple circuit using a TSOP2238 IR receiver, a PICAXE08M and an RC micro servo. The TSOP2238 allows any Sony TV remote to be used to control the volume and there are plenty of those around.

The servo will turn the volume knob of the amp. The servo is limited to about 180deg of travel, but that should be enough volume range for most of the hearing environments. The servo is attached to the knob using adhesive velcro pads to allow it to be taken out. The downside here is a velcro blob in your stereo volume knob...

By locating the batteries (3xAA) at the bottom of the enclosure, they will act as a "keel", keeping the enclosure reasonably still, forcing the knob to turn and not the other way round...

The code developed recognizes the Up/Down buttons as well as the Mute. Pressing Mute again will restore the previous sound level. Unfortunately there's no auto power off, although standby consumption should be quite minute.

When starting, the servo travels to its lowest setting, so for a "match", before sticking the velcro pad, the volume knob should also be turned to the minimum.

In practice, everything went according to plans, and it turned out to be quite useful, working smoothly and having a very good IR range.

I'm attaching code and schematic, and photos can be found here:
[http://pjrebordao.backpackit.com/pub/1449748

I hope I managed to be clear...

Great project.
Your hyperlink includes the ']' and doesn't work if you click on it.
For those who need a larger turning range than 180 degrees, just make the servo a continuously rotating one and adjust the code a little. Then you could have any amount of rotation.

Cheers,
Mike

Thanks for the tip on the link.
However, I'm not sure if modifying a servo to continuous rotation will work here, as I think you'll loose the ability to position the servo where you want...

The hyperlink is no longer active. Does anyone have copies of the photos from the original hyperlink in post #1. Thanks very much

ap