I have an 8 pack of sonoff basic wifi relays that I'm going to try to use with Smartthings. But I want to maintain manual control via standard wall mounted toggle switches. All the tutorials I've found thus far require replacing the toggle switch with a momentary switch and I'd prefer not to do that.
Is there any reason I can't set GPIO14 as an input, tap off the +3.3 Vcc and run THAT through the toggle switch (instead of 120 VAC) and into GPIO14, then control the lights manually based on the state of GPIO14? (ie, low = off, high = on)? So long as the impedance of GPIO input is sufficiently high and an appropriate pulldown resistor is in place, I can't think of a reason this isn't feasible. Has anyone tried it? If not, I should have results later today.