Parallel Paths Guidance

Hey guys, i couple of months ago i started a little project where i would unlock a gate with either multiple push buttons or cap sensor near my desk....On the bench test everything worked fine, once in place it would work sporadically..i would get ghost triggers from my cap sensor due to temperature and humidity changes in the room and or the digital read would get triggered by noise in the mains due to brown outs...

So i decided to go analog to avoid more headaches, but i need some guidance

I am currently running a timer relay in "delay off" to allow 5 seconds "gate unlock", its trigger is a 5v high, that would come from a push button @5v connected from a voltage regulator 7805 also i want a nano to trigger the relay BUT also need some edge detection to sound a buzzer ( i really dont want to spend more time on this using a RC and a 555 to sound the buzzer) here is where my dilemma comes in...

Since im running push buttons at 5v to signal the relay and a parallel path from the arduino output pin to the relay how can i protect the output pin when i trigger the relay from the button?? it came to me when i was writing the sketch and i set the Output pin to default LOW..

Without a schematic, we can only guess. And if I have to guess, I would use blocking diodes to isolate the parallel paths from each other. But that's only a guess.

Sorry about the schematic. That's what i thought using diodes, but also though off a pic817 or multiple channel relay board so everyone is isolated, damn this adhd...

let me whips something up so you guys have a clearer view.

here is a very simplified diagram,

So i decided to go analog

In what way is this analogue?

or the digital read would get triggered by noise in the mains due to brown outs.

It is more likely you were getting mains interference not dropouts. Anyway with long runs you need to take measures to suppress mains pickups with suitable resistors, capacitors and inductors.

As you have learned scaling up is not a simple matter of making the wires longer.
.
See De-coupling

And
http://www.thebox.myzen.co.uk/Tutorial/Protection.html

Grumpy_Mike:
In what way is this analogue?

For the most part analogue
Not using a sketch to detect push button presses nor the cap sensor.

Grumpy_Mike:
It is more likely you were getting mains interference not dropouts. Anyway with long runs you need to take measures to suppress mains pickups with suitable resistors, capacitors and inductors.

As you have learned scaling up is not a simple matter of making the wires longer.
.

Tell me about it, the problem is that where i live brownouts are a daily occurrence and we need backup generators, additionally mains are not as stable as in the states, you can get from 90vAC to 150vAC at any given moment making everything a nightmare... I bring this up because the cap sensor i was using relied heavily on earthing and for some mysterious reason to me everytime my backup generator would kick in the sensor would start signaling the arduino on a loop thus triggering the relay, even though everything was running off a UPS as to at least give it some stability.

The problem with mains pickup is that there is no other way to run the wire besides the same conduit as a mains line, it is embedded in a concrete wall so i cant do anything about it but going straight analog thus running the push button at 5v not even ground...and hope for the best.

For the most part analogue

No, just because you are not using a processor does not make a circuit analogue.

even though everything was running off a UPS as to at least give it some stability.

Look up what UPS stands for. I think you need a better one.

The problem with mains pickup is that there is no other way to run the wire besides the same conduit as a mains line, it is embedded in a concrete wall so i cant do anything about it

Yes you can. There are lots of techniques to combat mains pickup, like low impedance differential buffers at each end. Or tone encoding.

Grumpy_Mike:
No, just because you are not using a processor does not make a circuit analogue.

I guess your right, it was just a small banter..dont take it so serious

Grumpy_Mike:
Look up what UPS stands for. I think you need a better one.

Probably..!!!

Grumpy_Mike:
Yes you can. There are lots of techniques to combat mains pickup, like low impedance differential buffers at each end. Or tone encoding.

I mean you clearly are a highly skilled individual in electronics as for i, im just someone who dabbles once in a while with hobby electronics for fun, Im not planning to take this further then what it is, a trinket!!! something to play with, no need to be condescending after all i believed this was a forum for all levels.

after all i believed this was a forum for all levels.

It is indeed so when you talk about not being able to do anything is it not time to take your skills to another level? Am I supposed to just say nothing when challenged with something that is clearly wrong?

Grumpy_Mike:
It is indeed so when you talk about not being able to do anything is it not time to take your skills to another level?

Completely agree with you, but its not anything is SOME THINGS that i do not have expertise for; i have a solution its not the most elegant nor efficient, that is why i am asking for guidance, not to write me a sketch not to draw me a diagram, just a simple "hey why don't you try this or that" and i take it from there...

Grumpy_Mike:
Am I supposed to just say nothing when challenged with something that is clearly wrong?

Challenged how, when? i think you mistook my comment, what i meant is i do not have the abilities and knowledge must of you have, thus i am not able to comprehend let alone accomplished the mains pick up dilema, it is way above my abilities. I AM NOT an electronics and communications engineer nor have i ever claimed to be..

I decided to use a 4 channel relay board that feeds to a separate delay timer relay, its not pretty nor efficient but that way i can be sure that every path is isolated....