Arachnid - Dual Eeprom

[Moltenmetalburn]

Thanks for the reply! Are you using the 1p8t rotary switch to switch between eeprom? So you redesigned the board?

Yes 1p8T, no I didnt lay that one out as I preferred, four eeprom 2p4t and indictor lights. will probably fab that eventually. ive got 50 of the duals to off first lol.

 

[Robert]

Bad news on the stomp idea, if you’re wanting it to instantly change programs.

I have a theory (untested) on how you can instantly change programs when swapping to another EEPROM....

 

[phi1]

My theory would be to use an attiny to control pins 16, 17, and 18. Then you could pulse them 0-1 quickly to trigger the fv-1 to fetch eeprom. Hopefully there’s a more elegant way.

functionally, if just stomping to change eeprom could change the program, but not which patch # (1-8), and not the pots, that’s pretty limited function. So to me a fully integrated microcontroller system (pots, patch #, which eeprom) would be needed to get really useful stomp switch program changing (presets essentially).

Now we may be into territory the daisy seed would handle more elegantly, though it seems enthusiasm has slowed on that front?

 

[Robert]

I think we can do it with the footswitch and no additional components. (edit: okay, maybe one resistor)

Like you said, it doesn't add a huge amount of functionality, but it'd seem more intuitive to me if flipping (or stomping) the switch actually had an immediate effect.

I haven't lost interest in the Daisy (or the FV-1 for that matter), I just haven't had time to tackle anything I want to actually do.

 

[fig]

I just haven't had time to tackle anything I want to actually do.

I kinda noticed you are an extremely busy person.

 

[Robert]

I believe it can be done with a standard latching footswitch (or toggle switch), no microcontroller needed.

I'll have to dig out one of my FV-1 builds to test my theory.

 

[JamieJ]

I believe it can be done with a standard latching footswitch (or toggle switch), no microcontroller needed.

I'll have to dig out one of my FV-1 builds to test my theory.

Looking forward to hearing your potential solution, all the parts has come in for my build.

 

[huy]

This is my 2nd Arachnid build, my first was the old version with the potentiometer to select patches. This new version with the 8-way switch is much nicer.

Since PedalPCB hasn't released a dual eeprom board yet, I had to cobble together my own on perfboard. If @PedalPCB does release a dual eeprom board, this would be the configuration I'd vote for, since the most obvious application is to use it on an Arachnid board, and I was able to keep it in a 125B. It was a little tight having the switch at the top under the power jack, but doable.

I included shots of the dual Eeprom daughterboard, and a drawing of the layout. Following info previously provided from PedalPCB, you can select Eeproms by manipulating Pin1. Pin1 low (0v) is activated, Pin1 high (3.3v) is deactivated. As he also noted, fliping the toggle switch doesn't automatically change programs, you have to move the 8-way selector switch before the fv-1 will recognize a program change.

It was tricky soldering the pin headers onto the bottom side of the perfboard, since I had to leave a space between the plastic and the perfobard to get the iron in there. I just noticed that in the pictures that you can see I didn't get solder to fill all the way around on some of them (oops), but the connections all still registered with the multimeter. I used a piece of white foam from Tayda's dip socket packaging to support the cantilevered part of the daughterboard. I had to be careful about the order of soldering (8 way switch, then daughterboard, then mix pot).

For Bank A I used mostly spacialist reverb patches, with a code tweak on the shimmer so that it's only octave up. For the B side, it's a mix of PedalPCB patches (kaleidescope and sample hold), patches I found online, and some I wrote myself. I used my dev board build with exterior eeprom socket to test all the patches and flash the A and B chips.

**EDIT** - the pdf on my original post had an error on the perfboard layout (see p_wats comment on 8/10/2020). I marked up and reattached the pdf.

Can i use this board on FV1 Development board?

 

[phi1]

If you just want to toggle which eeprom is making the sounds, yeah it should work on the same principle.

If you also want to toggle which socket gets flashed, you can use a DPDT switch to connect/disconnect the PCB pins 5&6 to the sockets. I don’t have a perfboard layout. You don’t need any resistors.

On my own dev board, I have one internal eeprom and one external mounted to the side of the enclosure to make it a flashing station for other projects