Automated Doggy Door - Access Issue

I’m making an electronic Doggy door (crude prototype pictured) using:

  • RPi 3
  • Adafruit Wide-Range Triple-axis Magnetometer - MLX90393
  • INA219 High Side DC Current Sensor
  • 34:1 Metal Gearmotor 25Dx67L mm MP 12V with 48 CPR Encoder
  • TB9051FTG Single Brushed DC Motor Driver

The door part works fine. However I need to find a better solution for access control. Currently I’m using the Magnometer to sense a magnet on the dogs collar. While it works, it’s far from ideal.

I’d like to use RFID. However I need 20-30cm read distance from the Reader to the tag for it to work. To achieve that distance I think I need an Active tag (battery powered) which I’m having trouble sourcing.

An alternative may be some type of Bluetooth proximity sensing (as suggested by Trent at Core)
Hoping someone may have some ideas?

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Hi Graeme

You really need this to identify YOUR dog. Otherwise you might have lots of stray dogs or even cats gaining entry.

I know this might sound silly but could you train your dog to push a light weight button or even put his nose against a capacitive touch switch to gain entry. Most dogs are pretty smart and I think would be trainable to do something like this.
Cheers Bob

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Hi Bob,
Excellent point. I have no desire to make this any more hi-tech than it needs to be. Our small dogs (Westies) currently tap on the door to be let in. So yes, I think a simple bar (switch) across the bottom of the door entry would be easy for them to learn. And much easier for me to implement. That said, I’m open to other suggestions.

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If that is what they do now this would probably work. It is surprising how quickly dogs can learn something like this. If something similar is what they have to do to get where they want to be I would think they will learn in a couple of days.
Good luck
Cheers Bob

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Hi Graeme,

I’m not sure what active RFID devices are out there but they seem quite rare compared to their passive counterparts. This does make some intuitive sense to me because the whole point of RFID/NFC was to not have to power half of the system.
The passive devices range will max out well below 30 cm even in the best circumstances so we can definitely rule that out as a viable option which leaves either another wireless protocol, object identification or dog training as the alternatives.

As Bob has pointed out training your dogs to tap a bar switch when they already tap at the door is likely to be far less effort than any electronic solution so that would be my go to.

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Hi Trent,

Thanks for you input. I take your point on RFID/NFC.Not really designed for my use case.

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Hi All :slight_smile: and Welcome back Graeme!

Just coming from a security view NFC might be a good option, but the range limitation might be able to be solved the same way that Bob suggested, if you could train your dog to rub its collar on a reader you could authorise entry (you might need a few tags so attached though…)

The bar would be a great start!

Liam

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Thanks Liam, It found this on ebay, an RFID solution. A little too expensive.

https://www.olidesmart.com/products/olide-504w-smart-pet-collar-sensor-and-receiver

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Hi Graeme,

That is a fair bit of money to be putting into just the tags and receivers but I guess where there is a need someone will sell a product for whatever people are willing to pay.

Keen to see what you come up with given the resourcefulness present in the build so far.

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Hi Trent,
Yes I agree. As you originally suggested BLE may work. I came across this tutorial

I’ll give it a try and let you now.
Thanks again,
Graeme

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Hi Graeme
Yes a bit pricey especially as it is most likely $US. BUT it looks like it would do your job and by the time you source enough bits for an electronic solution you might find a similar price tag. But maybe not as much fun or educational.
Cheers Bob

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Hey @GRAEME51636, sorry I’m a little late to the party here.

Check out “Priority 1 Design” down in Melbourne. You might be able to get away with one of their large coils and read your Mutts’ microchips.

I’ve had one of their boards sitting new in its box here for a while and have recently decided to try installing it under the stairs of our home to help track the whereabouts of our two furry monsters. (Current thinking is that the easiest way to determine direction is going to be to employ two readers on different steps.)


- Greig.

1 Like