We learned last week my golden retriever has bone cancer and we will be amputating his leg and likely starting Chemo very soon. Consequently I'm moving his dog door to the main fenced in backyard of our house in order to avoid stairs and allow him access anytime. We have another old girl who would appreciate the same thing.
I'm not too worried about the code but I've so far been surprised to not see a clear tech choice for an application like this. Essentially I'd just like to toggle a motor and lock sequence based on a unique ID that can be triggered by a tag within a few feet (1M).
Here's a breakdown of my research so far (and this may be a wrong interpretation on my part):
1a. Passive RFID - not enough range, and particular about orientations.
1b. Active RFID- maybe this is viable but I haven't been able to find a low cost tags plus scanners that are also small and ruggedized.
3. BLE- these seem like a good candidate, the nordic chips seem like overkill for what I need, but when touting their battery life, size, and convenience this might well be the winner.
4. RF- 433Mhz- I've never used these before but I think I actually have the modules. Cheap and easy seems appealing.
5. WiFi - probably not going to be efficient enough to be practical.
6. Retail- I backed a kickstarter once that ended up sending me two Stick n' Find modules. Miraculously I still have them. They are nice and small and utilize bluetooth claiming up to 1yr shelf life. Again with the overkill but givent their longevity and their size (about that of a quarter) not bad. Also, if I was able to even see the device pop up (when in range) my primary goal is already done.
7. Retail 2- my brother got me a MYNT module- much the same thing and reasons for the above.
8. IR sensor- This could work but I worry would be unreliable, particularly when surrounded by a giant long furry chest. Maybe I'm wrong here. Not sure if the battery life is comparable.
9. There are assorted amazon examples here and here but I don't see any indication you could get them to do anything with Arduino at all..
I'm sure there are more that I'm missing.. but you get the gist. I'm not going nuts with security features, we're usually home anyway and if not, this dog door is proabably the hardest way to break in in any case, so just using a particuar frequency or modulation would probably be fine so that it only opens for dogs. (this is why PIR or radar aren't good options) The only bandwidth I need is to transmit some (any) type of ID that can be used uniquely and received from either side of the door.
Anyway, most of the challenge with this one will be executing a good mechanical solution, but if I could just identify a source for a tag that can work with Arduino I'd at least have the electronic element sorted out. Thanks for any suggestions!