Slow response on digital brake input?

[davef_dci]

Hey folks,

I'd assume I'm having a basic electrical engineering brain cramp here but could use some debugging advice.

I have the brake switch input wired through a 10K resistor into GPPIO(1). this is mapped to a virtual channel Brake_stat.

When I press the brake, Brake_stat immediately goes to 1 - but when I release it, it's taking around 5 seconds to reset back to zero. I'm assuming I screwed up on my resistor choice or wiring and have some weird voltage decay but does anyone have an explanation for this phenomena?

Lua code follows:

brake_status = addChannel("Brake_stat", 10, 0)

(inside on tick)


if getGpio(1) == 0 then
setChannel(brake_status,0)
else
setChannel(brake_status,1)
end

[gizmodo]

It doesn't help your situation but I have a similar setup except I just wired the brake switch on my car to an analog input. Anything over zero and I know the pedal is being pressed. The brake switch on my car has a 12 volt signal.

[brentp]

You can try a combination of a 10K input resistor and then a 1K pull-down resistor on the RaceCapture side of the 10K resistor. this might help bleed off any residual charge.

Otherwise, connecting to an analog input is a fine idea as well.