No photo. It's just a complicated circuit board with small smd resistors all over the place.
The car has ground, but the signals often get their own ground wire or use a "sensor ground".
The ground circuit they have for signals (this one), is a "return" not truly a ground. Think of it as a dedicated VREF- just for this signal. I don't want to just throw that away since they found it important to have.
Tree / ladder... same to me.
So the idea I had was to use my micro to operate the gates on the fets to connect the signal wire to it's ground with the resistor of my choosing. Back to post 1
I'm not acutally sure about the mA needed. I have one of these with a 1k pullup with the ladder ranging from 100ohm to 15k. The other is 2000 pullup with the same ladder. I'm not actually sure how to calculate what the pot would see for amperage. See, I'm not that smart, and never really learned this stuff
Do you take the pullup and the extra resistor and add them then use ohm's to take V/R and that is it? Or is it just the V/pullup since that's the max potential source current? I'm not sure.
Thing is, I only have a couple days to prototype it so I'm leaning on just using resistors and if I get a second opinion (here) I'll use the fets.