3 way single button switcher circuit, instead of 3 way toggle

[texas_flood]

hi, i've been scouring the internet and learning electronics for the past 3 weeks in an effort to build my first project pedal.  so far i have a pretty good handle on how most electronic components work and am getting up to speed with the application of those components, but am still finding that i may not be researching the right things to learn what i need for this project.  i have a very good background in repairing and modding guitar electronics, but just not in building them from scratch.

basically, i have a fulldrive 2 pedal, the version with the 3-way toggle for selecting comp-cut, FM, or Vintage settings.  Therein lies the problem,  this pedal is my MAIN pedal and is my sound, and i like each sound setting in the toggle switch, but to access the different sound, i need to walk over to my pedal board, bend down and switch the toggle between songs (or sometime during a song).  i'm looking to create a solution to this by means of a separate "outboard" pedal that will connect to my fulldrive 2.

the outboard pedal will take the place of the 3-way toggle on the fulldrive 2.  i don't care how they connect to eachother, be it RJ45 or some other multi-pair cable.  the outboard pedal has to be as small as a single effect pedal, like as small as an MXR carbon copy pedal.  it needs to have only one footswitch, and with an LED configuration (either one with 3 diff colors, or 3 individual different colored LEDs) to show which selection is on.  just like the toggle switch, the external footswitch needs to only select one setting at a time.

i'm pretty firm on the solution having only 1 footswitch button because i need the switch to take up extremely little real estate on my pedal board.  i understand how the DPDT 3way toggle works, and i know how the guitar signal is currently routing through it based on the selection, but i just can't seem to find a premade example or anything close to what i'm looking for to mimic a 3 way toggle switching circuit into a single button format.  i've explored IC relays, programmable IC's, low current relay circuits, and anything i can come up with based on my limited knowledge.  so now i'm reaching out to people that have reputable expertise.

can anyone point me in the right direction?

[mth5044]

Can be easily programed with a microcontroller. A month ago, I would have said 'anything but a microcontroller', but I've picked up a picaxe and done some experimentation and it's really not that hard, especially with a picaxe (it is also inexpensive).

For a simple, straightforward picaxe way, I'd do this:
Use a 5 pin midi jacks and cable to connect the switch bank to the pedal. One of the pins will send 5v to the button bank and connect to one side of a momentary switch. The other side of each switch will have its own pin on the midi cable going back to the pedal.

Each switch goes into a separate input pin on a picaxe 14M2 inside the main pedal. When one of the buttons is pushed, the pin on the microcontroller will see the 5v (high) from the button bank and a program that you wrote will, depending on which voltage pin is high (depending on what switch you press), tell one of the output pins on the microcontroller to output 5v (high). This output is connected to a CD4066 switch, which is configured to switch between the components that change the sound you are looking for. I drew up a diagram. You can also program the microcontroller that when one of the buttons is pushed, it automatically turns the other button off and switches to the new one (so you don't have multiple ones on at once, or you don't have to hit two switches).

It's quite easy! I've left out some minor circuitry needed for it to work, but that is the basics of it.

[Processaurus]

I've gotten interested in microcontrollers too, but there is also a lower tech approach that can work here.  To the original poster, it could be helpful to study the use of the CD4017 counter IC.  There is the datasheet, but also some examples of use in pedals, such as the Vanishing Point sequencer.  It is an interesting IC for translating several presses on a button to a number of different states, as it functions by setting 1 of 10 different outputs high in sequence, and advances by pulsing the clock pin.  0,1,2,3,4,5,6,7,8,9. You get it do loops of less than 10 (like, 012,012,012,) by hooking output 3 to the reset pin, so the instant output 3 goes high it resets to zero.

You could then form your center off DPDT toggle switch by hooking output 0 up to the control lines of two SPST analog switches in a CD4066, and output 2 up to control the other two SPST switches.  Output 1 is the center off position, so it doesn't need to be hooked to anything.

If you had three footswitches, you could use a latch to make a radio station type pushbutton bank, where pressing one resets the others, note the use of a 74C373 octal latch in this interesting Geofex article:
http://www.geofex.com/Article_Folders/multivol/multivol.htm

[pappasmurfsharem]

If his toggle is just a DPDT switch, why cant he just sub it for a DPDT footswitch?

[Paul Marossy]

If his toggle is just a DPDT switch, why cant he just sub it for a DPDT footswitch?

Because it has three positions. Must be an ON-OFF-ON type.

[pappasmurfsharem]

Ahh yes, he did say three options didn't he.