View Full Version : [Question(s)] deadman switch ideas?

03-19-2008, 02:45 PM
I'm posting this for Clint of Coding4fun. I wanted to see what other ideas people have.

Hey Matt, for my skateboard segway, I’ve been thinking about a deadman switch and thought up the idea of having 2 of those super strong magnets taped to inserted into my shoe with some type of sensor that could tell the on / off state.

Good idea? Do you have any better ideas?


03-19-2008, 02:48 PM
I think that the magnets would work, but one would have to be pretty accurate to line up magnets and reed switches. I think larger area pressure pads would be more reliable. The FSR strips (http://www.trossenrobotics.com/store/p/3223-24-Inch-Force-Sensing-Resistor-FSR-Strip.aspx) come to mind.

Who else has ideas?

03-19-2008, 03:13 PM
Did you show Clint Rodger's Leviskate (http://forums.trossenrobotics.com/showthread.php?t=1334) yet?

03-19-2008, 04:00 PM
I was thinking about two FSR strips with a Phidget Voltage Divider.

How tight of a turn can I make with the FSR strips? Can I shorten the FSR?

03-19-2008, 06:24 PM
Yes, you can cut it shorter.

I don't think you should try to bend/coil a strip tighter than around a soda can, but I could be wrong on that.

03-19-2008, 07:19 PM
when you shorten an FSR strip though, just remember that the section you cut off (without the leads) is pretty much garbage after that. Many have tried to use that section, most all have failed.

From what I remember Dave telling me, you don't want to put any bend in the strip.

03-19-2008, 09:02 PM
When I say "bend", I'm implying I can create pattern on the skateboard. Such as a U shape.

Not being able to reuse it isn't the end of the world. Maybe one of the 1.5" pads may be better then for my usage.

Or when applying the FSR 24", I could angle them out so (--\----/---) where the \ and / are the FSR strips. I cover more area and will no matter what be able to detect if someone is on.

Do I need to seal the end if I do cut the FSR? I'm just thinking 2 feet is a lot to work with.

03-19-2008, 11:16 PM
You can't bend them sideways like you are asking. I think your slight V pattern would get the job done. Strips would work better than the 1.5s IMO. They would cover more area and you can also keep the leads off the standing area. You don't want people stepping on those. Sealing the end may be a good idea, but probably not necessary.

03-19-2008, 11:20 PM
Yeah, I was going to have the voltage dividers under the board. Actually all the electronics will be under the skateboard.

I'll have more pictures this weekend with a near finished board.