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Program Selection Options

Posted: Tue Apr 14, 2020 8:05 pm
by johnott0010
Hey Everyone,

I've seen some posts on here regarding program selection (S0, S1, S2). I know the Arachnid uses that plastic rotary switch and the FV-1 Dev Board uses a rotary encoder. I have a bunch of questions regarding those inputs because I would like to implement a different solution.

I'm trying to avoid adding a MCU to the design, but if I did:
1. If I use an up counter in a MCU with a Momentary Footswitch, can I simply drive S0, S1, and S2 with GPIOs? Do I need pull-ups/pull-downs etc?

If I don't use a microcontroller and simply use some switches, what are my options? How can I make use of all 8 presets? Let's say I used (3) latching push button switches, could I use those to do binary and get all 8 presets (000, 001, ... etc)? Would those push button switches need "debouncing?"

I would love to chat about this stuff with someone who has done it because I'm laying out a board and trying to decide whether I need a microcontroller or not.

Thanks,

Re: Program Selection Options

Posted: Wed Apr 15, 2020 3:10 am
by ice-nine
I use a small pic chip to output the 3 bit binary code needed to switch s0-2 the pic is directly connected to these pins but if you take this route you must use a micro that is 3.3v otherwise you may damage the FV-1. The 8 position switch is set up as a resistor divider which connects to the ADC of the PIC Micro.

You could do similar with the 8 position switch with using diodes to obtain the binary output with no need for a micro at all.

your other idea of 3 latching switches will work as well, debouncing the switches ? maybe.

Re: Program Selection Options

Posted: Wed Apr 15, 2020 8:52 am
by johnott0010
Thanks for the response. That's exactly what I was looking for.

I think the most "elegant" would be to use the PIC and then I can use that for relay bypass as well.

Any suggestions on which PIC you're using and are you using an official Microchip programmer or one of the cheaper knock offs?

Re: Program Selection Options

Posted: Wed Apr 15, 2020 12:42 pm
by ice-nine
I am using a small 8 pin PIC12F615 for this, it still has 2 pins available which could be used for a bypass but one pin would be the switch and the other could control the bypass relay. It would be better to use a bigger PIC for LED and mute outputs if you wanted to have both bypass and program selection on the same Micro.