Spoke magnet/reed switch with KT controller.

[jarnold]

My hub has a freewheel, so can't use the hall sensors for speed/ distance measurements. The spoke magnet sensor is a two wire device, so probably a reed switch. On the outgoing Brainpower controller this worked fine connected to the 2 pin external speed sensor connector with a red and a white wire, which I assume was simply closing a circuit between the white and +5v. Is this going to be ok on my shiny new KT controller? I can't imagine it would damage anything, but I could easily put a 100 ohm resistor in series, just in case.

 

[saneagle]

My hub has a freewheel, so can't use the hall sensors for speed/ distance measurements. The spoke magnet sensor is a two wire device, so probably a reed switch. On the outgoing Brainpower controller this worked fine connected to the 2 pin external speed sensor connector with a red and a white wire, which I assume was simply closing a circuit between the white and +5v. Is this going to be ok on my shiny new KT controller? I can't imagine it would damage anything, but I could easily put a 109 ohm resistor in series, just in case.

It won't do any damage if you get it wrong. On some controller one of the wires can go to the ground and others to the 5v. One wire always goes to the signal. You have to try to find whichever way works starting with the ground. Actually, you can tell by measuring the voltage on the signal wire. If it's 5v, the other goes to ground. If it's 0v, the other goes to 5v.

 

[jarnold]

Thanks, pretty much what I thought. And that was supposed to be 100 ohm, I don't think 109 ohms is a preferred value in the E24 range.