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Comment by gbear605 | Hacker News Reader

What is it running in your car?

I have a custom piece of software that powers a display in the car, syncs and plays my music, and logs GPS. It also can manage audio and video recording and is intended to handle some future features[1] I have planned, so I wanted to over-spec rather than under-spec.

[1] It's the same software that runs my home automation system, so an inevitable feature is my car and home units interacting, I wrote half of a piece of navigation software before I stopped, and the entire interface is intended for voice control so I need to throw that in there at some point too. I intend to work on a CAN interface to connect to the car, but I've had a few roadblocks to getting started on that project.

Have you documented any of this or written on your home automation endeavors? I'm looking to "Tony Stark" my house up a bit (i.e. voice control, some touch enabled panes in the kitchen/office) but want a bit more control than something purpose built, off-the-shelf while also being a bit more insulated than Alexa or Echo. The NUC has been on my radar as a device that I may go with as the brains of the operation, and I'm just curious to read what design and implementation patterns others have taken.

I get asked to do more of a "write-up" a lot, but it's hard to figure out how to format or frame it. I have a fairly large pile of opinions about how one should go about doing this, but it's hard to concisely organize my thoughts on it into a coherent write-up.

The code is here: https://github.com/ocdtrekkie/HAController but I don't know if I'd really recommend others use it. The main perk to me is that it's designed around what I want and use (I tried a lot of alternative options before rolling my own), so unless you also really like Visual Basic code and have a brain ordered bizarrely similarly to mine, you may want to start somewhere else.

I'd love to chat about what I've learned along the way or what ideas you have (because I might borrow them!), if you want to chat elsewhere hit me up at inbox (at) jacobweisz (dot) com

What's the power draw like?

I once left the reading lights on; car was supposed to have turned it off when the doors locked, but somehow didn't. I found myself calling AAA in the morning to get a jumpstart.

Also curious, does GP have some way to shutdown gracefully when the car turns off, and reboot fast when it turns on? You could potentially handle this with a laptop and some battery-settings but not aware of an external battery solution for the NUC.

I currently use a laptop power adapter for the cigarette lighter, which is only on when the car is. The NUC's BIOS is set to turn it on when the power comes on, but I power it off manually before turning off the car. This is not ideal.

There is an external battery solution for the NUC, and I bought it! http://www.mini-box.com/NUC-UPS But I haven't switched to it yet. The big upside is that it will gracefully shutdown my NUC after I power off the car. But if I use the cigarette lighter for power, it will lose the ability to turn itself on when power is present, because the batteries are always present. NUC UPS supports using a different power connector which can turn on the PC on ignition, but I haven't had it installed in my car as of yet as that's a little bit more work, and I'd need some help from someone who knows more about the car's electrical system.

As far as fast power-on, it's a pretty high end i5 NUC with an NVMe SSD. It boots pretty darn fast, and my software takes less than a second to load once the OS is up. The slowest part of boot is that I don't want my location history easily steal-able, so it's encrypted, and I have to key in the code to unlock the machine. (I'm looking at a security key or similar to replace this step in the future.)

As a note, I'm more or less specced out what's involved in a solar power setup on the roof of my car to independently power my computer all/most of the time when the car is off and otherwise charge a secondary battery off the car's inverter, but there's no reasonable or sane reason to do it. ...But I thought about it.

Thanks. Curious, where do you stash the NUC in your car? I imagine it's insulated and not exposed -- otherwise a hot day or a very cold day might kill it.

Actually, it's pretty important for the NUC to get good airflow so it doesn't overheat; insulating it would be a bad idea! I haven't had any temperature-based issues with it, in part because most of the time the car is running I am in it, so I keep the temperature at temperatures I am comfortable in. And the NUC's temperature range is pretty wide as well, which is good, because weather here ranges from -10 F to 110 F.

Probably the only real concern I'm afraid of is condensation when heating up the car on a cold day, but it hasn't been an issue so far, perhaps because the computer is not near a window.

You don't want insulated and hidden, you want perforated and airy (while still being discreet).

The NUC-like hardware that goes into tanks have chassis consisting of a mesh cage to allow maximum airflow since the cabin temperature alone can exceed 100F.

It should be pretty easy to hook up a microcontroller (think Arduino nano) to "press" the power button when the power from the lighter comes on.

Since I'm not a hardware guy, I try to avoid assembling my own gadgetry as much as possible on this project. I use consumer grade home automation modules, standard computer parts where possible. (Everything in my car is largely interconnected with USB.) And generally, experimenting with the NUC UPS aside, I try to avoid parts that may be hard to replace. Which is to say, I don't have time to build, test, and fix a random Arduino gadget. ;)

I've been planning to make some custom-cut USB cables and a 3D printed part just to make the setup of my display a lot cleaner... and I haven't done either of those and it's been a year or so since I planned to.

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