RF signal to LCD screen?

Hi guys

I want to (try to) make a notification device for my folks' guesthouse. Here's the short version...guest presses button, remote LCD screen displays which room needs attention (room number...just a 01 or a 02 etc), would be great to add a queue maybe that changes numbers every 1 second. Maybe another button to deactivate that room's number on the screen to leave the number on the screen that is second in the queue.

Can someone point me in the right direction here please? Would RF be my go to shield here?

Many thanks.

Hi,
How far apart are the guest buttons and the call register screen.

You can use RF modules for each of the buttons with receiver at the display.
What power supply is available at each site.

Tom..... :slight_smile:

Yeesh Tom that was quick, thank you so much.

It's not really a big place...4 rooms, normal size house.

We run 220 volt power in South Africa. I'd like to have the transmitter on batteries and have the receiving unit run from a plug. Receiving unit connected to the screen...maybe something like a 40 inch LCD. Am I thinking in the right direction here?

Thought about getting cheap 433mhz transmitter and receiver. Have the transmitter send a signal to the receiver and have that display a number on the screen.

Well that's the initial idee, maybe someone can help with something better?

I would use NRF24L01+ modules for that application.

They are very cheap and handle a lot of stuff
you would have to program yourself with the cheap 433MHz modules,
like acknowledge, retries, bidirectional links, ...

For a simple button its a litte overkill,
but once you have a communication from desk to room and back,
maybe you come up with some other ideas using it.

Thanks Whandall

AS I was sitting here it dawned on me that it would work great in their little restaurant as well...I think.

Few tables nothing big, but I know that some guests in the restaurant get cranky when the waiters bother them too much asking if everything is fine or when guests struggle to get the attention of the waiters.

So I thought it would be great to have a RF transmitter on the table (just a little box with a button) and have the receiver display the table number on the screen....again with the queue. If you press the button again it cancels the table in the queue. I know I always get upset when I cant get the attention of our waiter and I look like an idiot staring over peoples heads trying to remember what the heck our waiter looked like :wink:

Just get the waiters in the habit of looking at the screen.

So you would need some kind of feedback to the user at the table (a lit LED).
(easy with the NRF because the sender knows that the receiver copied the message)

You could in addition display the next number to be serviced on a big LED display (flashing),
that would be very hard to ignore.

I think that sounds about right Whandall.

I was thinking to have a number display for 2 seconds and then have it change to the next number in the queue. If you press the button again at the table/room it just removes that number from the queue.

The user at the table/room doesnt need to get feedback. Will have to put up an large enough screen in a place where the waiters will be able to see the numbers easily.

DoubleJ:
The user at the table/room doesnt need to get feedback.

Shure, if you want him to hit the button many more than once,
kicking the number in and out of the queue and messing with the order of entries (with your strategy).

I really think a 'waiter is on the way' or 'service still wanted' led would make life easier,
especially if you want the user to be able to cancel the request.

Whandall:
Shure, if you want him to hit the button many more than once,
kicking the number in and out of the queue and messing with the order of entries (with your strategy).

I really think a 'waiter is on the way' or 'service still wanted' led would make life easier,
especially if you want the user to be able to cancel the request.

Good call, pretty sure that's something a little green lit LED when button is pushed can help with?

A little led would be much better than no feedback.
It's also a good go-no-go check for you.

Whandall:
A little led would be much better than no feedback.
It's also a good go-no-go check for you.

Most certainly,

So then it's a NRF24L01+ on the tables and one next to the display screen?

I see it looks like some folks are having problems powering these modules...

It needs a good stable 3.3V, you could use a 3.3V Arduino with 8MHz and a common supply,
or generate the 3.3V with an extra step-down converter.
I have some running off the 3.3V of a Nano just working fine.

You should add capacitor(s) directly to the modules anyway.

Another alternative is a ESP8266, it uses WiFi and
could even be made to execute your button/led/sending stuff without an Arduino at all.

Many thanks, much appreciated.

What power source do you use then if you run it directly off the Nano?

The Nanos are powered via USB.