feasibilty question, auto-fade audio volume

Hi all,

I have no experience whatsoever with Arduino, but willing to jump in and try it. I have a specific problem I'm trying find a solution for:

We have a low-power FM broadcast station, which is accessible via the internet for various remote operation (VNC, SSH, etc). Most of the time it runs on automated programming that we put on ourselves. We also go live, but the station manager who goes live has physical problems which makes it difficult for him to go to the station. We have two Exstreamer 500 units which allows him to go live from his house, via the internet.

What I'd like to do is have the automated programming volume fade out when he goes live, and fade back in when he disconnects. The station's Exstreamer has a relay on the back which we use to interrupt the automation, which works fine, but it doesn't sound good with the abrupt OFF/ON of the automation volume. Fading IN/OUT sounds much better.

Anyway, the challenge is how to fade the automation volume, and then back in when the Exstreamer relay engages/disengages. Does anyone have any suggestions?

Our present setup is the automation computer's audio-out goes to relay-controlled audio-switch. The Exstreamer's audio-out goes to the same relay board. The relay-board output goes to the mixer. When we go live or automated, the Exstreamer's onboard relay engages/disengages the relay-controlled audio board to abruptly switch "live" or automated audio. I can change that setup so the automation audio could go to some other board (Arduino circuit?) and then to another channel on the mixer, and keep the Exstreamer audio on its own mixer channel. I was thinking maybe a servo motor on a dual-gang potentiometer to fade IN/OUT the automation audio when the Exstreamer's onboard relay switch engages/disengages? The fade IN/OUT doesn't have to be slow, just maybe two seconds. But how can I tell the servo to stop?


substitute a digital pot for a manual pot in the mixer

You didn't specify much, if anything, of the device you want to modify. At the very least we need a part number, preferably also the complete schematics so at least there's some idea of what you're working with.
Now as it's some kind of automatic broadcaster, are you sure it doesn't have this function built into its own software already?

Motorised pot ?


A digital pot looks like the answer, using single DPDT momentary switch. Good write-up on it here (scroll down to page 2):


Thanks for all the replies. The moderator can close this thread, as the solution isn’t Arduino-related.