buttonswitches
I have a red laser pen module:
http://space-linker.com/Uploadfiles/UploadFile/2010178127739.jpg
I want to be able to have it always on.
How can I short the button, without having to glue or tape it down.
Is there a circuit I can cut across with the power?
Button:
https://cdn.sparkfun.com//assets/parts/9/0/00097-03-L.jpg
Thanks
simulate this circuit – Schematic created using CircuitLab
Figure 1. A 4017 flip-flop.
How it works:
This sorts out the logic. I think you can figure out the power switching.
Power-down warning
With the addition of the signal line to your micro-controller you have a 3 s warning to trigger a "save data" routine before the power is cut. Some logic may be required in the controller to suppress this during power-up, etc.
Best Answer
Yes, but...
You are removing the power switch and leaving yourself (and others) with no way to quickly disconnect power in the event of laser malfunction (fire) or immolation (laser setting something/someone in the room on fire).
Lasers can be dangerous!
Lasers can be dangerous, even small ones. Never point it someone's eyes. Treat them like a loaded gun -- always assume it is about to turn on and always point it in a safe direction. Remember reflections can also do damage, so avoid reflective surfaces and wear laser-grade eye protection.
That said... here's how:
Bypass the tactile switch by shorting across it's longest dimension as shown below. It doesn't matter which side (upper pair or lower pair from figures perspective) you use as the short sided legs are tied together internally in most parts.