Again manufacturers will use different chips depending on there functions.

I think I mentioned in a previous thread about RonJs circuits but it depends on what your plan is to achieve.

RonJ's circuits are a great start for good features from basic components, if you want to get more complex then I think using a SBC like Arduino will be more flexible for you and have greater scope in the long run.

One benefit of using a SBC is if the project is a failure you can easily re-purpose for the next challenge, much better than having random chips on the shelf that will never be used.

 

It depends on what you want the project to do, the best and most satisfying projects are the ones with practical applications. Equally you can always set yourself a task to complete.

The link in my last post has code examples for an Arduino keypad, the keypad uses a grid membrane. A challenge could be to make a functional LCD keypad unit that will transmit to your Arduino over a 6 core alarm cable, for example.

This challenge will need you to make a circuit to encode a membrane grid, transmit then decode it for the Arduinos inputs much like what we spoke about with the Accenta. You can design whatever protocol or transmission you like.

 

As you say I see no problem in starting with your idea of a keyswitch alarm using Arduino and take it from there, maybe I have given you some ideas.

I'm just impressed @Gabs has scope that's worth a good 10x the price of new "ade" controls

2 hours ago, MrHappy said:

I'm just impressed @Gabs has scope that's worth a good 10x the price of new "ade" controls

Thanks, glad you like it, its a handy thing to have  I am after an Accenta G4 Actually, don't have one in the collection... Although, it isn't real ADE

I nearly bought a scope some yrs back to fault find a CCTV job, they used to be very expensive CRT things.... But now a few a thundred quid.

 

I'd love one but have no practical use for it.

21 minutes ago, MrHappy said:

I nearly bought a scope some yrs back to fault find a CCTV job, they used to be very expensive CRT things.... But now a few a thundred quid.

 

I'd love one but have no practical use for it.

We have one in the office I rarely use it and I am the only one who knows how to use it (Or what it is for that matter) 

@MrHappy Treat Yourself https://www.amazon.co.uk/Hantek-DSO5102P-Digital-Oscilloscope-Real-Time/dp/B00I5EWF1U/ref=pd_sbs_263_1?_encoding=UTF8&pd_rd_i=B00I5EWF1U&pd_rd_r=9259545f-0aef-11e9-84e9-0f828c410421&pd_rd_w=7sYyD&pd_rd_wg=cH6IT&pf_rd_p=18edf98b-139a-41ee-bb40-d725dd59d1d3&pf_rd_r=H994SW1EBCCXA65WKYB1&psc=1&refRID=H994SW1EBCCXA65WKYB1 Really good to have, even if it is for looking at the secret language of the Accenta 

3 minutes ago, PeterJames said:

We have one in the office I rarely use it and I am the only one who knows how to use it (Or what it is for that matter) 

 

Glad you employ decent engineers Peter

Seriously though a scope can be sooo useful.

Scope was one of the weapons of choice back when I used to repair TVs, couldn't be done efficiently without one. The one we had in the shop was a clunky Radiospares one iirc. 

Never used one as an alarm engineer although ADT had one in the stores. 

i have one, fluke LCD thing. used to be used for balancing inputs on multiplexers. can't see what id use it for now

13 hours ago, Rulland said:

 

Glad you employ decent engineers Peter

Seriously though a scope can be sooo useful.

When I used to repair tv,s they were essential, nowadays sadly its cheaper and easier to replace something than it is to repair something. I cant think of anything in our trade where I would use it.1v ptp on a camera why bother? if you fix it, the customer will expect 12 month warranty on it even if a different component fails.  The only thing I use mine for is for R&D and it rarely gets used for that, when you can buy almost anything you need off the shelf.