button shifters

[Pico2]

I have been having troubles finding appropriate buttons for the shifter for our car. I'm looking for Momentary on buttons with a positive feel and about 3/4 inch in diameter.

Any suggestions on where to find them?

[EgyptianMagician]

Originally posted by Pico:
I have been having troubles finding appropriate buttons for the shifter for our car. I'm looking for Momentary on buttons with a positive feel and about 3/4 inch in diameter.

Any suggestions on where to find them?

You'll have to be more specific about "momentary on buttons"...

What is your setup consisting of? Are you just taking the signal right from the button without cleaning it up first? Where is the signal going after it 'leaves' the button....

More info = more answers http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Pico2]

sorry about the lack of info...

The setup is controlled by a microcontroller. Basically the button has a voltage that, when pressed, is grounded (pull down setup). The microcontroller detects this and does the shifting.
So the button doesn't see a large amperage.

[Agent4573]

how is the button activated.... i mean radioshack sells almost exactly what you describe....

[Pico2]

push button

[osubeaver]

We use a power window button from some ford vehicle and it is quite nice since it has an up and down rocker action which is perfect for shifting. It is a momentary contact switch with a nice click to it.

[EgyptianMagician]

Originally posted by Pico:
sorry about the lack of info...

The setup is controlled by a microcontroller. Basically the button has a voltage that, when pressed, is grounded (pull down setup). The microcontroller detects this and does the shifting.
So the button doesn't see a large amperage.

Sounds pretty resonable.

check www.digikey.com, (http://www.digikey.com,) whttp://www.goldmine-elec.com/default.htm, ebay, etc... you will find something.

Or like the other guys said, junkyard http://fsae.com/groupee_common/emoticons/icon_smile.gif

words to search for, push button, press button, tactile switch ...etc..

Also, don't foget to debounce your signal, but I'm sure you've already done that.

[Chris Boyden]

try push button switches from
ITW switches. they are about the
nicest push button around IMHO for this
application.

http://www.itwswitches.com/newsite/products/pushbutton.htm

We've used the series 59 for push button shifters, and starter buttons.

IP67 Waterproof, tactile feel, really nice.
rated for about 1 million operations.

[EgyptianMagician]

those look rediculousy over priced ... can you tell me how much you paid for them? How exactly do the hall effect sensors work in the button? That's kind of confusing me...


Originally posted by Chris Boyden:
try push button switches from
ITW switches. they are about the
nicest push button around IMHO for this
application.

http://www.itwswitches.com/newsite/products/pushbutton.htm

We've used the series 59 for push button shifters, and starter buttons.

IP67 Waterproof, tactile feel, really nice.
rated for about 1 million operations.

[Chris Boyden]

Hey man, you get what you pay for. Did you
even bother to price them out??
But, if you are worried about cost
try the sample button. And if you're that
worried about cost, why are you
doing push button shifting?
What's all this talk about hall effect sensors?
I think you're looking at the wrong datasheet.
series 59 is what we used.
you were looking at 49.
On the plus side, hall effect switches probably don't need to be debounced, but code is cheap, and parts are not.

[Pico2]

Yeah, I'm liking the ITW Switches... I just bought a couple. Series 49-59. Pretty nice switches and they're completely closed. Got 'em through Newark at a pretty good price too. Thanks for the suggestion!

Sean

[EgyptianMagician]

Nope, that's why I asked, I said they looked over priced, then again a Kia Magentis also looks like it costs a lot, I was just asking.

I might have had the wrong data sheet, I was trying to figure out why the hall effect, but I'm sure there's a reason (some crazy military harsh enviro spec ...)

Because push button shifting is cool, and that's the only reason I can think of any team going to all these lengths.

FYI MC14490 -- 7$CDN, debouces nicely (hope she hold together)

Thanks for the tip, I'll see if I can get some samples, would be cool to play with regardless. But I did like the suggestion of a junk yard ... also I was thinking, go to a Benz dealership or some high end dealership, find some nice buttons in the car, and then see if you can get the parts at Cost ... might work, gonna see what Honda has in their fancy dancy cars tomorrow since we have employee pricing.

Fun fun this 'tiptronic' stuff, gives the electricals something to do.


Originally posted by Chris Boyden:
Hey man, you get what you pay for. Did you
even bother to price them out??
But, if you are worried about cost
try the sample button. And if you're that
worried about cost, why are you
doing push button shifting?
What's all this talk about hall effect sensors?
I think you're looking at the wrong datasheet.
series 59 is what we used.
you were looking at 49.
On the plus side, hall effect switches probably don't need to be debounced, but code is cheap, and parts are not.

[osubeaver]

FYI MC14490 -- 7$CDN, debouces nicely (hope she hold together)

Do you use debouncing on your shifter? Does your ECU take car of the shift control (ignition kill, etc..) or did you build a separate circuit for the shifter?

[raska]

We're using pretty plain tact switches not even momentary with a 20ms debounce and have no shift issues button related or other.

A seperate circuit takes the ignition signal from the ecu does what it needs to do, and outputs to the power transistors.

[EgyptianMagician]

Currently everything is modular, the shifter, and ign kill are togethere. We haven't purchased our ECU yet, so hopefully when it comes we'll just use it to tune the mixture, and we'll handle the ign kill.

And yes, for now just tacticle switches running through a debouncer, still all table top stuff, nothing mounted as of yet, that's why I was curious about the fancy dancy buttons.


Originally posted by osubeaver:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">FYI MC14490 -- 7$CDN, debouces nicely (hope she hold together)

Do you use debouncing on your shifter? Does your ECU take car of the shift control (ignition kill, etc..) or did you build a separate circuit for the shifter? </div></BLOCKQUOTE>

[Chris Boyden]

Sean,

Glad you like the switches....
I just wish ITW made a sealed toggle/rocker switch for the ignition switch. But, we'll probably go with a sealed toggle from del-city with rubber boot.

Hall effect switches are solid state devices that don't have contact erosion problems and should last forever. ie.10 million cycles

[gug]

Originally posted by EgyptianMagician:
Currently everything is modular, the shifter, and ign kill are togethere. We haven't purchased our ECU yet, so hopefully when it comes we'll just use it to tune the mixture, and we'll handle the ign kill.

ign kill was simple with our motec, just another input. i would say its worth selecting your ECU before bothering making an external ign kill.

[EgyptianMagician]

Originally posted by gug:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by EgyptianMagician:
Currently everything is modular, the shifter, and ign kill are togethere. We haven't purchased our ECU yet, so hopefully when it comes we'll just use it to tune the mixture, and we'll handle the ign kill.

ign kill was simple with our motec, just another input. i would say its worth selecting your ECU before bothering making an external ign
kill. </div></BLOCKQUOTE>

Probably a good idea, but I'd have to ask "what does it do other than kill the ignition for a specific amount of time" ... And then of course there is cost. If it's cheaper to buy the whole pacakge, then maybe we'll do just that, unless we see room for improvement. I myself would prefer to build it from scratch using the Megasquirt as a base concept and building from there, but we shall see.

As I mentioned, the "prototype" control board is using a simple transistor input with a TVS to handle any strange spikes that could fry the transistor. Go in on Vcc and take the voltage from Vc, switch the base from the micro. I guess we'll soon see what happens.