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Replacing switches - Printable Version

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Replacing switches - Catprog - 10-04-2017

I am planning to have a shift register control the power and reset buttons.

Do I need a transitor or can I put the output in directly?


RE: Replacing switches - MarkHaysHarris777 - 10-05-2017

(10-04-2017, 09:28 PM)Catprog Wrote: I am planning to have a shift register control the power and reset buttons.

Do I need a transitor or can I put the output in directly?


The premise of your question makes no sense;  please elaborate and explain how you think a shift register might control power and reset buttons .


RE: Replacing switches - Catprog - 10-05-2017

(10-05-2017, 02:49 PM)MarkHaysHarris777 Wrote:
(10-04-2017, 09:28 PM)Catprog Wrote: I am planning to have a shift register control the power and reset buttons.

Do I need a transitor or can I put the output in directly?


The premise of your question makes no sense;  please elaborate and explain how you think a shift register might control power and reset buttons .


What I am trying to do is electronic control of the power and reset functions.

IE the actual button will be removed and replaced in some way with the  output from the IC


RE: Replacing switches - MarkHaysHarris777 - 10-05-2017

(10-05-2017, 08:08 PM)Catprog Wrote:
(10-05-2017, 02:49 PM)MarkHaysHarris777 Wrote:
(10-04-2017, 09:28 PM)Catprog Wrote: I am planning to have a shift register control the power and reset buttons.

Do I need a transitor or can I put the output in directly?


The premise of your question makes no sense;  please elaborate and explain how you think a shift register might control power and reset buttons .


What I am trying to do is electronic control of the power and reset functions.

IE the actual button will be removed and replaced in some way with the  output from the IC


I was questioning the shift register, mostly.

Two things you will want to do;  check the datasheet schematic(s) and check the function of the power button and reset button functions;  they may surprise you !

A PN2222 or 2N2222 general purpose NPN transistor ( or similar ) can be used in place of the switch , with a gpio pin from another MCU or SBC via 1K resistor to the base of the transistor will work just fine for an electronic switch.  Also a 4N35 opto-coupler could be used.

The switch is providing a ground shot;  the transistor can do the same thing.

The reset is a hard reset !   not a good thing to do unless you ( or the watch dog ) knows that the system is not functioning;  you should not press the reset of a running system !

The power button has both a long and a short press function;  and a very long press function.  They do not work the way most people expect them to.  Do some research.


RE: Replacing switches - Catprog - 10-06-2017

(10-05-2017, 11:29 PM)MarkHaysHarris777 Wrote: I was questioning the shift register, mostly.

Well I have 48 switches to control (24 x 2)