Digital audio input selector

Hey guys,

Got stuck while brainstorming for my new project.

I’ve got an analog input selector for my stereo but… I wanna make it arduino. And double the inputs (already got an exact copy of the stereo)

The schematics for the input selector are quite straightforward. In big lines:

4 signals come in, go to a rotary switch, one of the signals will be send forward. (see attachment)

To increase them analogly I’ll just have to circuits with an increased rotary switch (8 positions instead of 4)

The thing is I want to be able to use a rotary encoder… Why? So I can keep turning the knob instead of moving in forward and backwards… Besides I’m able to use a remote control.

Here’s where my head is starting to glitch…
I could simply use 8 relays with input… But I’ll get a clicking noise each time

So I’m wondering is I could use like a 4 channel analog switch like a dg411… (or two to get 8 channels) and if yes… How I should connect this

If I look at the data sheet the chip will need 4 different signals… But I’m kinda hoping I could do it with less :slight_smile:

Kind regards!

Or you could use a mux like 4051 that directly selects 1 of 8 inputs.
Clicks are due to different DC levels on the inputs, to avoid that you basically need a capacitor in series with each input and a resistor (100kOhm would probably be fine) to GND after the capacitor. You must also supply the mux with both positive and negative voltage. They have 3 pins: V+, V- and GND, where GND is for the logic ground.

HKJ-lygte:
Or you could use a mux like 4051 that directly selects 1 of 8 inputs.
Clicks are due to different DC levels on the inputs, to avoid that you basically need a capacitor in series with each input and a resistor (100kOhm would probably be fine) to GND after the capacitor. You must also supply the mux with both positive and negative voltage. They have 3 pins: V+, V- and GND, where GND is for the logic ground.

I was thinking about using shift registers (like the 74hc595) to increase my outputs and maybe use one of them to control an analog switch.. Would this be the same as using the mux you named?

njiua:
I was thinking about using shift registers (like the 74hc595) to increase my outputs and maybe use one of them to control an analog switch.. Would this be the same as using the mux you named?

Not the same, it is a different way to do it. With a mux like 4051 you need 3 outputs to select input. I do believe you can find similar muxes in the DG series, if you prefer to use them.

A 74HC4052 is a two-channel 4-way analog switch controlled by just two digital lines (thus four combinations). If you want two-channel 8-way, you need either two of these controlled by four lines or two 74HC4051 controlled by the same three lines.


You do need to bias the signals (and use isolating capacitors) to a 2.5 V reference level to maintain the voltage through the switches in the range between 0 and 5 V.

Have been researching quite a bit today to find the following conclusion.

Like Paul says: the dg is a 4input 2 out multiplexer/switch
The 4051 is 1 to 8 channel

So basicly both chips to the same job.. But for the project I'm doing I do indeed need the 4051.

Thanks for the replies!

Paul__B:
You do need to bias the signals (and use isolating capacitors) to a 2.5 V reference level to maintain the voltage through the switches in the range between 0 and 5 V.

If you do that you will also need a capacitor on the output.

njiua:
Like Paul says: the dg is a 4input 2 out multiplexer/switch
The 4051 is 1 to 8 channel

You can get both series in many different version, DG508 is 8 input.

Check Mouser for the possibilities

I've been working with a similer project and ended up using TDA7318 chip instead of PT2314 as an audio selector.