I have to create a Circuit for Panic Control System
The system will be comprising of
How long has the teacher given you to complete the work ?
Same here as in school:
Why did you not prepare a drawing? Draw one and post it here.
Why did you not prepare a program code? Write one and post it here.
If this is homework or anything like that, please post the assignment as it was given to you, or post a link to it.
We cheerfully do ppl's homework on these fora alla time, but only if we have the assignment, not a paraphrasing of it.
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Show us your best code attempt, even if it doesn't work, and we'll try to help you by suggesting changes to it.
But remember: Use tags when posting your code.
This is not a homework or an assignment. It is just a volunteer work that I want to do to help a nearby hospital to help them in situation of emergency. If anyone can help, it will be highly appreciated.
Thank you
Done anything like this before have you?
So a real hospital then, so you need to be very careful.
The real problem is the length of wires between the switches. You can't extend a switch more than a few feet and get reliable operation.
You need some sort of differential buffer on the send end, and a matching receiving differential buffer on the receive end.
In the past I have used this sort of arrangement :-
Yes you are right the switches are almost 100-300feet away from the panel. I need to develop a design that is more comprehensive
That also means your equipment will be subject to periodic cleaning and disaffecting with powerful chemicals. It also means your wiring will have to be in the walls and/or the ceiling.
Good point. It is not for nothing that these things are very expensive to buy and install in real hospitals.
Then you might consider a radio network. One good reason why your hospital doesn't already have one, may well be the prohibitive cable installation costs.
Would not use rf/ethernet/wifi connections.
Whould use 2 wire rs485 connection that run from master panel to all emergency locations.
The master panel cyclically polls all locations to acquire/send status ( 0.1sec x location, 10sec x all locations ) all location has different address.
That could be considered life saving equipment and the Arduino and most commercial vendors specifically state you must have there written permission. The best advice I can give you is have them buy a qualified unit and run away from this as fast as you can. If it fails even years down the road it could be your liability.
All I can say is good luck, I will not be offering help because of the liabilities I may face if it fails.
Does this still have to work properly when the mains power is off? Does it still have to work when the emergency generators stop working?
Legalities should prevent one from doing this.
For alarm system wiring like this, always include a supervision resistor.
Something like this:
using 120VAC wiring would work. Each switch has one set of normally closed contacts which are wired in series to the next station and eventually to a master relay and one set of normally open contacts to denote which station activated. Most of the 'brains' will be in the master panel.
Search "E-stop circuit".
Think about mesh network using several ESP8266 or ESP32.
Unfortunately, same here.
The regulatory, compliance and safety issues are steep.
I’ve designed one of these before using call pendants and POCSAG radios. fun but tricky.
