The lack of LEDs on the FS-6 to tell you whether the effect is on or off is, to me, a nuisance - especially during a performance. Is there an alternative foot switch with lights out there? Better yet, TC. How about adding lights to the unit? Cheers!
I hacked together my own Switch 6. The circuit details were published by justjamie and its basically a passive circuit with a resistor ladder with 7 10K resistor in series between of a stereo jack ring and sleeve with one side of the 6 switches on the 6 resistor nodes and with the tip wired on 6 switches common wired,
It basically senses the voltage on the tip and activates the assigned function. Smart usage of just reading one analog input and 6 switches. In theory you could even use 12 or even 24 switches with just one analog input.
You could put a momentary LED when using s dual pole momentary, but to lit a specific LED you need some more circuit logic to set the LED permanently.
It would be easier if the Play would support MIDI CC commands over USB and connect a Behringer FCB1010 Midi Foot Controller trouhg a Raspberri PI converting the MIDI to USB. I did something similar with a Line6 PocketPod but that thing emulates a standard MIDI device and it listens to MIDI Progam an Control Change MIDI data.