two-stage pushbutton switch, sort-of DPDT?

[jayeye]

My parametric search abilities are failing me here, and digikey does not allow me to do a raw SQL query

I need a small pushbutton switch with two circuits, both normally open. When I push the button halfway, the first circuit is closed, and when I push it all the way both circuits are closed. Does such a beast even exist?

(Of course I know I can have two pushbuttons one next to the other, press one, then press the other. Or do it with a 556 to have a delayed monostable pulse, and it will probably be cheaper than the pushbutton switch, but still...)

The use case is having a one-finger operation for putting the ESP8266 and its ilk to upload mode: you pull GPIO0 low, pull RESET low, release RESET, release GPIO0. It *has* to be done in that order, can't even do it simultaneously (as if simultaneity existed in circuits, but that's for another show ).

Cheers,

/ji

[jeroen79]

How do you want to use it?

For something to use over and over during development I would go for one switch and some small microcontroller.

For something to use once in a while in a finished product I would add in a double dip switch.

If you want to build something yourself then you could use two switches.
One is linked to the button with a spring, press it enough and it clicks.
You can then press the button further until it touches the second switch.

[Doctorandus_P]

These doulbe switch thingies are used in different applications.

Some examples:
- Foto camera's where a half puch starts the focussing sequence and a full push makes a picture.
- Musical keyboards where the time difference is measured to calculate the velosity of the key movement.
- Some specialised relays where a "big" contact takes the stress of opening / breaking a circuit and is bridged by a more sensitive contact during closing.

It's because of stuff like this that I do not like to use bootloaders, and prefer to program uC's with a "decent" programmer.
Put a target in a makefile for programming, which starts a command line uitility to talk to hardware that programs your shit.
Takes a bit of work to setup, but you only do it once and there is no more need for complex Vulcan Finger Salutes to your hardware.

I doubt you can buy off the shelf products for this, probably too specialized.
You can however make something like this fairly easy yourself.
Just take 2 regular push buttons and a lever.
Put one button on the end of the leaver and the other near the hinge.
The button near the hinge gets actived first, and when you push harder the second buttons gets activated.

[MarkF]

Would an ignition switch type (Off-On-Momentary) work?

   https://www.amazon.com/Momentary-Ignition-Toggle-Switch-Terminals/dp/B00JWZ8NYO

[Psi]

Most of the 3 position tack switches are On-On-Off
So in idle state they are on, press down a bit a different circuit is on, press down more and they go open.

On-On-Off
https://www.digikey.com/product-detail/en/judco-manufacturing-inc/50-0089-00/543PB-ND/935976

On-Off-On
https://www.digikey.com/product-detail/en/judco-manufacturing-inc/50-0041-00/529PB-ND/611178

[Dundarave]

A quick google using the string "three position push button" produced

https://www.otto-controls.com/p2-3-position-momentary-action-pushbutton

among other hits...  The switch described in the link above looks like it has the action you're seeking. The form factor might be another matter, however, but it looked reasonable.

[jayeye]

A quick google using the string "three position push button" produced

https://www.otto-controls.com/p2-3-position-momentary-action-pushbutton

among other hits...  The switch described in the link above looks like it has the action you're seeking. The form factor might be another matter, however, but it looked reasonable.

Yes, this is exactly the sort of circuit I want. The form factor is an issue, though, but I'll keep it in mind for my missile-launcher project

Cheers,

/ji

[jayeye]

These doulbe switch thingies are used in different applications.

Some examples:
- Foto camera's where a half puch starts the focussing sequence and a full push makes a picture.
- Musical keyboards where the time difference is measured to calculate the velosity of the key movement.
- Some specialised relays where a "big" contact takes the stress of opening / breaking a circuit and is bridged by a more sensitive contact during closing.

It's because of stuff like this that I do not like to use bootloaders, and prefer to program uC's with a "decent" programmer.
Put a target in a makefile for programming, which starts a command line uitility to talk to hardware that programs your shit.
Takes a bit of work to setup, but you only do it once and there is no more need for complex Vulcan Finger Salutes to your hardware.

I doubt you can buy off the shelf products for this, probably too specialized.
You can however make something like this fairly easy yourself.
Just take 2 regular push buttons and a lever.
Put one button on the end of the leaver and the other near the hinge.
The button near the hinge gets actived first, and when you push harder the second buttons gets activated.

I like the lever idea, but this would be a small enough part (the switches are 3mm square) that 3d-printing it on my ultimaker won't have enough accuracy or even structural strength, and I don't have access to a proper mill to machine it (also, not the sort of thing I can just design and send for fabrication, it would need several iterations. In another life, maybe )