# Not Exactly a Machining Project



## macardoso (Dec 12, 2019)

Hi All,

Thought some of you might enjoy this. Wife and I have 3 cats but often end up traveling out of state for work and holidays. We have a neighbor stop in to feed them, but we are always worried about our kitties! Rather than constantly text her to see if she stopped by, or install a camera (kinda creepy?), I figured I could put my micro-controller and programming skills to work.

I used a magnetic reed door switch to sense when the door is open. The switch is tied to a digital input on a NodeMCU Wifi enabled micro controller. These are around $3 on Amazon and are quite powerful for a basic micro.




I programmed it in the Arduino IDE and used a web service called Blynk to create an iPhone app that displays the data I want. My project was simple enough that I could just use the free features within Blynk.

Here is the simple app I built (yes... I know my phone is almost dead). It creates a push notification (ding!) whenever the door opens, time stamps it with an accurate RTC reading, displays an on screen LED to tell me if the door is open, has a button to clear the history, has a big display for when the door was last opened, and a 10 line table to show the time the door was opened as well as the duration of the visit and how long between visits. I might change the big display to show an incrementing time since the last visit.




Maybe 5 hours of work and $15 of hardware needed ($10 of which was a USB cable from Home Depot  ) to get this to work. I have programmed Arduino compatible micro-controllers for years now, but always thought that web interfaces were out of my reach.

The machining part of this will be a simple case for the micro-controller and a better mount to stick the magnet on the door.

Mike


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## Boswell (Dec 13, 2019)

NodeMCU's are awesome. I have three installed on my water tanks. each uses an ultrasonic sensor from MaxBotix that is mounted on the top of each tank to read the distance to the water in mm. It then calculates the number of gallons left and transmits that to my Home Automation system using HomeSeer. And to tie this to Machining: I had to make an adapter our in Aluminum that had 1" internal 11-1/2" tpi and 3"  external 8 tpi to mount the sonar sensor to a bulkhead connector I installed on the top of the tank. This was my first single point threading project.


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## Janderso (Dec 13, 2019)

See, it's projects like this that make me feel quite inadequate.
You sir, are like Einstein, to me.


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## brino (Dec 13, 2019)

If it wasn't for the output (litter box), you could also easily control the input (feeding) remotely.
I could see an internet-enabled cat feeder with rotating disc to control portion size, or even a feed screw to deliver food.
Add a video camera and voice capability and you could even "call them for dinner" and see them charge over.

-brino


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## homebrewed (Dec 13, 2019)

If your cats are chipped you might be able to read its ID and unlock the cat door when it approaches, blocking access to other critters.

Lest you think that is a theoretical possibility, we had a raccoon figure out the cat door.  That was Not Good.


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## macardoso (Dec 13, 2019)

brino said:


> If it wasn't for the output (litter box), you could also easily control the input (feeding) remotely.
> I could see an internet-enabled cat feeder with rotating disc to control portion size, or even a feed screw to deliver food.
> Add a video camera and voice capability and you could even "call them for dinner" and see them charge over.





homebrewed said:


> If your cats are chipped you might be able to read its ID and unlock the cat door when it approaches, blocking access to other critters.
> 
> Lest you think that is a theoretical possibility, we had a raccoon figure out the cat door. That was Not Good.



You guys might not believe it, but I've seen all of those ideas for sale Unfortunately that would set me back many hundreds of dollars. We like that the neighbor gives them some play and exercise too. 

That's hysterical (to me... not you) about the raccoon and the cat door. I bet that was quite the adventure to get it out!


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## macardoso (Dec 13, 2019)

Here is the final install.

Machined some HDPE (I think) to create a spacer for the magnet on the door. It is secured with some nice double sided tape.




Bought 50' of what 4 conductor telephone wire which I ran from the side door, through the basement stairs, across the ceiling, and down to the nearest outlet (46' away!). I also got some nice nail in cable clips to organize the wiring.




The NodeMCU was mounted inside a cheap little plastic box with a flip close lid. Used the CNC to remove the ribs of plastic where the micro needed to go, and a ball endmill to cut holes for the cable entry.




Here was the best outlet I could get to  




And our all black cat "Pink" going out for some exploration today .




Think this project is all wrapped up!


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## homebrewed (Dec 14, 2019)

macardoso said:


> I bet that was quite the adventure to get it out!


Not as much as the time a squirrel fell down our chimney.  They can really go nuts when confined (at least the raccoon knew the way out!).  We also had birds nest in there a few times, until I made a chicken-wire cover for the chimney.


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## Boswell (Dec 14, 2019)

Racoons can be a nuisance but they don't panic and don't get lost if they get inside. A Squirrel that is loose on the inside of our house is a major Pain. They panic, They can't seem to find the way out, even when it is just a few feet from them.  ...


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## mmcmdl (Dec 14, 2019)

The word possum is banned in our household . One stopped by years ago to snitch up on catfood on the back porch . Of course the 3 Shelties homed in on it in an instant . Now whenever someone says possum , all he&& breaks loose !


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