DIY IR remote volume control addon for stereo receiver

[Emory Smith]

I would like to build a remote volume control for my older (non home theatre)
receiver. The audio/vca section is no problem for me, I just can't find info on
the IR receiver/decoder section. There are IR receivers available at Radio Shack
but info on how to interface and program them escapes me.

Goals:
1. To be able to be controlled by an inexpensive universal remote using the
"Audio" button on the remote. Ideally, it would mimic a known home theatre
receiver so that I could just program the remote by holding the "Audio"
button and entering a three digit code.

2. To power up in a sane mode. Volume at 10% or so, NOT 100% or mute.

3. LED bar graph for gain/attenuation indication.

4. To be an external unit connected to the receiver's eq/processor loop.
No problem here. I have elex fabrication facilities.

If I get it going, I'll post complete info here.

Thanks in advance for any info,

 

[Active8]

I would like to build a remote volume control for my older (non home theatre)
receiver. The audio/vca section is no problem for me, I just can't find info on
the IR receiver/decoder section. There are IR receivers available at Radio Shack
but info on how to interface and program them escapes me.

Goals:
1. To be able to be controlled by an inexpensive universal remote using the
"Audio" button on the remote. Ideally, it would mimic a known home theatre
receiver so that I could just program the remote by holding the "Audio"
button and entering a three digit code.

what three digit code will you enter? one for an equip you don't plan on
having, i'd think.

a search will turn up IR projects. use whatever circuit frags you need.

so get an IR receiver and figure out the pulses the remote spits out for
volume control.

search for IR decoder chip or use a link someone provides. can't
remember how they work, but the info's out there.

2. To power up in a sane mode. Volume at 10% or so, NOT 100% or mute.

you'd want to do that with the digital section of your rcvr. figure you
have a digital pot. or programmable opamp. make sure the word for your
desired start up volume is loaded on power up. good job for a PIC.
decode the IR pulses for vol+/vol- and run those sigs to 2 pic inputs.
program the PIC to increment/decrement the VCA control word which will
be output on however many PIC I/O lines you need for your digital POT or
whatever you're thinking of using. DAC => transconductance amp?

can't remember, but i think one of those digital pots has a non-volatile
memory. you'd have to return the volume to "sane" before you power down.

www.microchip.com - have fun.
www.google.com

3. LED bar graph for gain/attenuation indication.

lots of bargraph chips/projects out there. a bunch of comparators would
do it.

4. To be an external unit connected to the receiver's eq/processor loop.
No problem here. I have elex fabrication facilities.

If I get it going, I'll post complete info here.

use a web site, please. this isn't a binary group.