There are use cases like this: https://xingular.io/en/solution/
Yes, that’s a good idea, we have a calculator in form of a spreadsheet, we will publish it.
I hope it will be available in 4 weeks from now, at least the button variant. Currently the mobile app and firmware are not finished. Hardware will be assembled this week. Confirmed upstreams are not supported yet by the firmware.
That’s not two button presses a year.
Why calculate a 9 year lifespan on such unrealistic usage?
Such hype does nothing to advance our industry and making such claims amongst a technically literate community like this can only impact on n-fuse’s credibility.
Sorry, it was mean “per day”. Corrected it.
The button will be pressed by a lever as the weight of the feed is removed.
The message could be transmitted once the button is pressed, but I thought to prevent missed actions it would be better to periodically send the button state
Periodically like every 2 hours.
Battery operated
The smaller the better, but ideally smaller than 10 x 5 x 5 cm
The Antenne could be bigger, but ideally the bulk of the device will be small.
Should transmit atleast 250m, but ideally more
Wants to be less than £15
I can build circuitry, I’ve made pcb circuits and programmed Arduinos before, but if theres a finished product thats close to what I want may be easier. (The Dragino LDS01 is a good example, just not sure on range)
Its for personal use, and just at ideas stage, so sorry for the vague level of detail, but I’m just trying to understand what about and where the best compromises are. The technology sounds exactly what I need
Given we now know more on your use case it is probably a good solution - around price point, small form factor. Mount main unit in fixed position on bin, place the magnetic element on moving lever or what ever works and as position changes it will trigger (ope/close) contact for you . Battery powered, decent life for a few cycles per day, largely sealed unit suitable for deployment location. Just need to be careful with mounting/orientation of main unit and if the feed bin is metalic you may need to adapt position/mounting to ensure antenna not detuned or blocked in direction you are trying to communicate with GW(s) etc. IMHO for the price just buy one and try it. Where in the world are you located? Key to reception range, besides node mounting location/environment will be the position and height of receiving GW and any intervening clutter… 250m should be eintireley possible 
I’ve seen similar small units (measuring T&H) deployed in similar environements talking to farm or zoo buildings 200m-1km away from cow sheds, zoo huts, and horse stables…
Thanks. That gives a much better impression of your use case and will prevent many responses from users that will not be relevant for your situation.
The button will be pressed by a lever as the weight of the feed is removed.
So button is actually quite misleading here.
Wat you need is a switch, not neccesarily a ‘button switch’.
If I interprete correctly, the feed bin (as in container?) will contain (large?) supply of horse feed. When the bin is empty a notification needs to be send (regularly until refilled).
The notification signals that the bin needs to be refilled with new supply.
For reliable use in stable environments your solution will need to be dust and moist proof.
A momentary micro-switch will probably be most suitable here. They come in all kinds of models for different mechanical situations (with levers, rollers etc).
But depending on the actual situation an optical or magnetic sensing/switching solution may also be applicable.
You price point is very ‘optimistic’ even for a DIY solution.
Depending on components used for a DIY solution expect at least double that amount for the materials (LoRa devboard, case, external antenna, battery, switch and cabling). And for a finished ready to use product (probably) much more.
This use case requires more than just a ‘simple button’ device.
Please don’t post ‘links only’ without any description.