Hey Siri, can I afford a home loan?

> The rest of this blog post is a walkthrough of a software engineer’s approach to home automation and building custom hardware, and let me tell you: both the final product, and the journey to get there, are hella jank.

IMHO it's not that bad? With the disclaimer that I'm also a software engineer who dabbles very very lightly with electronics and has no mechanical engineering expertise. But the overall approach of doing this by stepper motor seems quite defensible given the security deposit constraint. The only part that seems really janky to me is that it's not physically held in place that well as noted in this paragraph:

> Ultimately, the biggest issue is that binder clips and cardboard aren’t quite as robust of a mounting mechanism as I’d hoped they’d be… and over time, the stepper motor tends to “sag” a bit, resulting in a bit too much friction between the motor, the coupler, and the underlying knob, causing the mechanism to stall out until someone manually goes and reseats it…

Involving MQTT and HA can sometimes get frustrating too; having your AC not working properly if there's a problem on a Linux machine can suck. If this becomes a problem in practice, iirc ESPHome also has a thermostat component, and temperature sensors are really cheap and easy to wire in, so you could do it all on the microcontroller pretty easily in a low-code way. But if this part is working, no need to mess with it.

Instead of attaching the motor bracket with a binder clip, consider sticking it down with some sort of removable adhesive?

3M command strips should be very strong/secure, while also allowing for adjustment and will detach without residue when the time comes.

I was in a similar situation with my apartment PTAC unit, but mine has thermostat terminals — I would not be surprised if this one does too. I was able to hook up an Ecobee thermostat, with the downside being that it's way more expensive than OP's solution.

Assuming running a dual hose inverter portable AC isn't against the lease agreement it would probably pay for itself based on the power usage. Pretty neat hack regardless.

It's insane to me that some new construction buildings still use PTACs. Having used too many of those, this was a deal-breaker last time I was in the market for an apartment. Such a New York thing, just like how you cannot have a balcony on the 2nd floor, or how you won't find those sink garbage disposal grinders in any kitchen. But cross the Hudson toward NJ, and my understanding is that they're common. It's a combination of hyper-local regulations and economic incentives that date from god-knows-when and make American cities very unique in their quirks.

that's a fun project. i'd be a little concerned about the servos failing to fully switch the switches or placing wear on them, maybe a dangerous failure mode where it is switched into and left in an in-between state unattended that could lead to a fire hazard.

you can buy smart outlets with the correct connector, just look for 20A versions. (honeywell, at a minimum, sells one).

https://prod-edam.honeywell.com/content/dam/honeywell-edam/h...

The "couple a stepper motor to a shaft" API is so much better than any "smart" appliance API.

Speaking more seriously, I wish classes of appliances would expose some simple analog and digital interface pins in a standardized configuration to let users choose whatever automation or monitoring hardware they want. HVAC equipment does this with standardized thermostat terminals. I'd love to see that on other types of appliances, too.

The manufacturer's crappy "app" that will inevitably be abandoned and require keeping some old phone / tablet in good "health" lest you lose the "smart" functionality (or worse, any use of) the appliance.

Then current way of putting the "smarts" inside the appliance is just planned obsolescence and a recipe for all of us being eyeball deep in ewaste.

I have to say. Nice work. I spent years wanting to build something like this to integrate to these systems. I never did but have spent years thinking about this. So, nice work and really appreciate your motivation.