My RF controled PGA2320 MiniVol and ch selector

I got a lovely MiniVol board with the PGA2320 chip driven by a AVR microcontroller from diyaudio member, theAnonymous1. The minivol provides vol up/down and mute, controlled by push switches or a rotary encoder.
The MiniVol is described here -

http://audio.gotroot.ca/minivol/

I also wanted a channel selector. So I rigged up a small
circuit around a CD4017 to step through the channels.
The DPDT relays are driven via 2N2222s.

To control everything, I got a cheap 4 Channel RF controlled switch on ebay. The receiver has a couple of
jumpers to choose the mode - toggle, latch or momentary.
I used the momentary mode. The 4 channels are used
for Vol Up, Vol Down, Mute and Channel select.
The open RF receiver/relay board, and the remote alongside are visible in one of the pics.

The PGA2320 is a really nice volume control chip, sweet
and transparent.
I wanted an appropriate box, so I put
the whole thing in a Ferrero Rocher chocolate box!

I am also attaching the Eagle files for the channel select circuit.
 

Attachments

  • pre-6.jpg
    pre-6.jpg
    176.8 KB · Views: 1,677
  • pre-7.jpg
    pre-7.jpg
    148.6 KB · Views: 952
  • pre-3.jpg
    pre-3.jpg
    69.5 KB · Views: 946
  • pre-2.jpg
    pre-2.jpg
    244.1 KB · Views: 938
  • 4017-ch-sel.zip
    4017-ch-sel.zip
    39.6 KB · Views: 269
Last edited:
a chocolate attenuator 😉 😉

I've used those ebay rf remotes before (I designed a camera shutter/focus remote based on those rf modules). they are pretty cool and easy to interface with.

for the relays - if you can get away with you - you can use ssr chips and have those trigger some other thing. the RF receiver modules are 5v based, I think, and so you add a small series R and go into an SSR chip, then use the 'contacts' pins to control the relays. it might make it a little quieter in operation and simplify things. you can also get the rf receivers without the relays onboard and have a smaller package.
 
Thanks, I do unfortunately not own Eagle but your project looks great and you have understand something most, including me have not yet figured out.
It's a "crime" to hide a well made project inside an opaque box!🙂
EDIT: What about the sound, do the case make it particular sweet? 🙂

ebay do have a lot of great items, but they are often pre build🙂
 
Last edited:
Thanks, FriedMule - I agree, it is fun to have electronics which you can see.
The sweet box version was a quick prototype - later, the selector boards were
made by Sachin as a group buy in India. Just saw the date - it's 10 years since that was made!