Long range button/sensor

Devices
1

I’d like to have a button or door sensor for my mailbox, to let me know when it’s been opened. Problem is, the mailbox is ca. 100 meters from the house, and not quite in direct line of sight, there is some terrain in between. Do you know any intermediate range hardware that could manage this? Or do I have to use LoRa or similar, which would likely make it more expensive and troublesome than it’s worth.

Radio region: Europe. It must handle humidity and temps from -20 to +35 C. Battery power or solar.
I understand it could be done e.g. by hooking an arduino up to a LoRa 1-way Tx/Rx kit, and that would be an interesting thing to make, but feels overkill price-wise. I can’t easily run a cable to it since it has to cross a road.

2

Besides LoRa there isn’t much else. Even then, 100m without line of sight might be a stretch, depending on the exact situation.

3

Homematic CCU 3 Gateway, up to 400 meters. And if it’s not enough, you can extant the range (Link, sorry, only in German).
But I guess it will be also to expensive just to know if you have mail or not.

Just for info, I made my mailbox smart with Homematic devices (sorry, only in German):

4

I’ve heard some consumer RF 433Mhz products will go that far,.

My sliding gate remote control does about 80 meters no fuss.

If those don’t work there are some slightly higher wattage 433Mhz products that will definitely do 100m… Look on AliExpress…

LoRa will definitely do it with out any doubt. It gets incredible range, but there’s a limited range of products for it on the market though compared to 433Mhz …

5

Thanks all. Deutsch kein problem. I found some door bells on ebay that claim up to 300 or 400 meters range. Some hacking will be required to get them online, but it should be possible to hook them up to a Pi. If they can receive the signal in my case, that’s a cheap option. The lack of line-of-sight makes it uncertain.

6

For this sort of of application always go with the simplest cheapest solution …

433Mhz is pretty good at going through objects if you don’t have line of sight. What is in the way ?

7

Terrain, unfortunately. To work, the signal probably has to “curve around” it. Don’t know if it will do that. It’s not a 90 degree bend, just a slight 160 degrees or so.

8

Low frequency is generally good at bouncing off other nearby objects.

If you have some cheap 433mhz gear laying around (eg door bells etc etc ) maybe just experiment with those and see how they behave.

If not LoRa might be your only option other than cable …

9

FYI… In the future I’ve heard 5G mobile will be able to handle applications like this (maybe)

10

How 'bout this (not very legal probably), a zigbee repeater (500m)

or this

11

I’d like to stay within the regulations :slight_smile:
I’ll test with existing 433 gear, and see if results seem promising. Thanks all!

12

Yep… 433Mhz is simple , cheap and effective. (Also low power consumption) …

Low frequency rules. Perfect for this application… :grin:

Just have to see if the terrain is kind to you … :roll_eyes:

13

Have a look at the Heltec lora boards ,the stick or stick lite .Get two of these ,one in the mailbox and one sending the receiving message via mqtt too Homey.

1 Like
14

Update: I’m testing a 433 mhz door chime which promises 280 meters line-of-sight. When I give it a lithium AAA battery (slightly higher voltage than alkaline), it manages the 100 meters I need, if I lift it a meter above the mailbox. If only the magnetic switch wasn’t on the same circuit board as the printed-circuit antenna…

Next thing to try is to place the receiver outdoors, then I can bring it almost to a line-of-sight position. Then somehow connect it to Homey, perhaps via the Fibaro smart implant.