Author Topic: Simple Electronics Help  (Read 572 times)

Simple Electronics Help
on: March 22, 2019, 01:02:19 AM
Hi Folks,

I have an issue at work where I keep forgetting to lock my desk drawers. There's a policy which means that if I get caught leaving my drawer unlocked again I'll face disciplinary actions.

The lock is a built-in barrel combination lock on the draw.

I want to build a small electronic device with beeps if:

- Its after 5pm
- A the circuit is not completed (i.e. lock lever arm is not in the up position).

I have literally no idea how to do this.

Anyone able to guide me in the right direction? Single components? Audrino? Pi? 
Formerly sexytw

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Re: Simple Electronics Help
Reply #1 on: March 22, 2019, 01:16:37 AM
You can just use a sensor and smarthings for things
https://www.smartthings.com/products/-/filter/categories/sensors


And in the app just say to check when leaving.


If your doing it manually you just have to get the same sort of sensor and map it to your own board and get some code to check it is 1/0 at a given time and beep.

Re: Simple Electronics Help
Reply #2 on: March 22, 2019, 03:04:21 AM
You can just use a sensor and smarthings for things
https://www.smartthings.com/products/-/filter/categories/sensors


And in the app just say to check when leaving.


If your doing it manually you just have to get the same sort of sensor and map it to your own board and get some code to check it is 1/0 at a given time and beep.

Like it! I cant see any of these which would sense 'locked' vs 'closed' though, only want I can think of doing that is having an electrical circuit complete/break when the locking bar moves to the locked position.
Formerly sexytw

Re: Simple Electronics Help
Reply #3 on: March 22, 2019, 03:07:43 AM
I've just thought, I can probably simplify this and just have an LED light blink if the draw is ever unlocked.

So I should just need a battery, LED and a circuit which completes when the draw is unlocked?
Formerly sexytw

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Re: Simple Electronics Help
Reply #4 on: March 22, 2019, 06:37:49 AM
If you use Slack or Outlook or whatnot could you not just set yourself a 'lock the damn drawer' reminder?

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Re: Simple Electronics Help
Reply #5 on: March 22, 2019, 07:37:38 AM
I've just thought, I can probably simplify this and just have an LED light blink if the draw is ever unlocked.

So I should just need a battery, LED and a circuit which completes when the draw is unlocked?

Sounds plausible with a 9v battery  :thumbup:

Last Edit: March 22, 2019, 07:40:44 AM by matt5cott #187;
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Re: Simple Electronics Help
Reply #6 on: March 22, 2019, 11:14:02 AM
guessing if you have to keep the draw locked you don't want to post photos... google a pick of a similar lock?

easiest way is to just have a switch pushed by the lock when it's open, which turns the led on

if you go for 12v then you can use a car indicator relay to make it flash.... and it'll do the tick/tock noise of an indicator too?  which should not be annoying but should make you notice it?

tricky bit is where are you going to put the led... need it outside the draw so you can see it - how do you get the wires out?

Re: Simple Electronics Help
Reply #7 on: March 23, 2019, 16:39:52 PM
Love tekforums, can be away for 10 years and you still get well informed and genuine responses.

There’s enough room over the front of the draw to run a wire for the LED. I think I can do this Super simply with something like that 9v diagram as Long as I can get a reliable connection when the lock is unlocked.

I’m try and get a pic next week of the lock. Should be ok.

Formerly sexytw

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Re: Simple Electronics Help
Reply #8 on: March 25, 2019, 02:01:04 AM
You can just use a sensor and smarthings for things
https://www.smartthings.com/products/-/filter/categories/sensors


And in the app just say to check when leaving.


If your doing it manually you just have to get the same sort of sensor and map it to your own board and get some code to check it is 1/0 at a given time and beep.

Like it! I cant see any of these which would sense 'locked' vs 'closed' though, only want I can think of doing that is having an electrical circuit complete/break when the locking bar moves to the locked position.

There is the specific door and window sensors listed there just for that purpose.

  • Offline bear

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Re: Simple Electronics Help
Reply #9 on: March 26, 2019, 11:09:56 AM
Keep it locked always, it locks when you close and you need to unlock each time for access :)

Re: Simple Electronics Help
Reply #10 on: March 26, 2019, 12:28:39 PM
Just get one of these then the key is always handy to lock and unlock....

Sometimes the simplest solution is the best :)

https://www.amazon.co.uk/Heavy-duty-Retractable-Chain-Inches-Steel/dp/B01MTXY9HP/

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Re: Simple Electronics Help
Reply #11 on: March 31, 2019, 00:52:18 AM
There are several different options, including changing the lock to a night latch style as on doors. You shut the draw, it locks.

A buzzer for when the draw is open might be a better option than a LED.

Then the average desk lock isn't really up to much if you wanted to pick it.

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