Actions
Forum Thread Details
  • Replies 3 replies
  • Subscribers 304 subscribers
  • Views 3423 views
  • Users 0 members are here
Related
See a helpful answer?

Be sure to click 'more' and select 'suggest as answer'!

If you're the thread creator, be sure to click 'more' then 'Verify as Answer'!

How can I simulate a button press

dzavoo

Hey!

I am new to this field and I may not understand some terminology correctly, anyways,

 

Currently I am working on a project that releases smoke when the on/off button is pressed, I need to simplify the mechanism

and I want it to immediately start working when I plug it in to power source (without physically pressing the button).

 

I tried removing button entirely from the mechanism and I connected the "in" and "out" wires directly to each other

(without connecting them with a button) but it registered as a long button press, I need it to register something like a short impulse, like the physical button does.

 

How, and with what, should i connect the "in" and "out" wires together so it will trigger and simulate a short button press?

I dont have any access to board's software so i have to do something with the hardware or i can add another board to the system.

 

Thank you very much!!

  • Hi David,

    Couple of this come to mind.

    1. You could try wiring in a relay instead of the switch. If you want to simulate a button press you could McGuyver a setup with a capacitor and relay. Once the relay is depleted the switch goes to 0.

    2. I'm sure there is a 555 microcontroller circuit that can be built to send the switch pulse on power. Minimal parts.

     

    Back in my amateur radio days guys used to use these types of circuits for roger beeps at the end of tx. I'm sure one of those could be modified to work for you.

     

    Possibly someone else may have a better suggestion. Will see if I can find a circuit and post here.

     

    Cheers

  • You should be able to create a power-on pulse with a capacitor and maybe a resistor.

    If the button shorts out a signal to ground, then just a capacitor where the button was will "keep the button pushed" for a short time. A large resistor across the capacitor will ensure it gets reset for the next power on sequence.

    If the button supplies power when pushed, again putting a capacitor where the button was will cause a "button push" on power-up. In this scenario a resistor may be needed from the output to ground to make sure the capacitor signal goes away in a reasonable time.

    If the capacitor is large, you might want a diode to ensure the signal doesn't go negative.

  • in reply to dougw

    Thank you!

    but what type of resistor and capacitor would you recommend and in what size?

     

    The button I need to replace is similiar to this one goo.gl/EVZgWd

    and my entire machine uses only 1W of power