Using arduino to control analog circuit

Using Arduino Audio
1

Hi, i'm a new user of arduino.

I usually work with analog circuit for guitar. I wanted to use arduino to control a lot of resistor and switch in order to make preset. I need to control:
-14 resistor
-2 relay
-10 switch
Do i need some DAC? Does anyone know what can i use as variable resistor? there is an IC that has 14 digital pot? Any one know what ic contain 10 spst?
Thanks 1000

2

Try [u]Digi-Key[/u] to search for components. You don't have to buy from them but they sell almost everything. Their digital search form indicates you can get a chip with 6 digital pots.

I'm pretty sure I've seen dual (stereo) digital pots, but I doubt you'll find a chip with 14.

I did a very-quick Google search and [u]TI[/u] has a chip with 6 analog switches.

Make sure to check the voltage & current ratings for the "analog" components, and you may have to take extra care to prevent switching noise with analog switches. (Audio can be tricky because you can hear a tiny bit of noise when there's no signal to mask it... If you play electric guitar I'm sure you've had hum/buzz/noise issues.

Do i need some DAC?

You don't need a DAC to control a digital pot.

...This sounds like a "big messy project", and you should probably start-out with something simpler... something that takes a couple of digital pots & switches... Whatever you are doing, there's probably a way to do it digitally in software,* maybe with a [u]DSP chip[/u] (not with the Arduino). I'm not saying it would be "easy" with a DSP chip... I've never used a DSP chip, and it's another level of programing, it's probably a hard-to-solder SMT chip, and it may be expensive and it might require you to buy a development kit.

Or, you could use a computer... Depending on what you're doing, that could require some heavy DSP programming and you'd have to "fight" latency (delay caused by the mult-tasking operating system), but you wouldn't have to build anything. (You might want to get a "proper" guitar-USB interface because the mic input isn't "right" for a computer.)

  • A long time ago I was thinking about building a project and my design/schematic was getting very complicated (on paper before I built/breadboarded anything) and was getting overwhelmed it just didn't seem worth doing. Then I got my hands on a little microcontroller development kit (this was before the Arduino) and I realized I could do all of the complicated stuff in software rather than hardware. I used the microcontroller and everything worked-out great!
3

My intent is to build a big muff that could contain all the version of the schematic in one. The big muff has a lot of version, but remain the same skeleton (Here the hystory of this circuit). so i want to stay analog, but, as you say, it's a big mess because i need to control:

  • 5 emitter resistor
  • 3 collector resistor
  • 3 volume pot
  • 2 tone pot
  • 4 frequency resistor
  • 3 tone wicker switch
  • 8 diode switch
  • 2 diode knob
  • 4 tone switch
  • 2 relay for bypass
    i know that could be do it because chase bliss made a distortion circuit, with preset, midi etc. that it's called Brothers. I know it's difficult, but i would start with a simple signal booster called SHO and then i will expand the project. but i guess it's impossible :confused: :confused:
4

As DVDdoug says:-

Audio can be tricky because you can hear a tiny bit of noise when there's no signal to mask it.

But if you just want to control digital pots then try your SHO with one of these.
https://www.arduino.cc/en/Tutorial/DigitalPotentiometer