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A comment on Crankshaft – A GNU/Linux for the Raspberry Pi as an Android Auto headunit. Parent comment

Re:Crankshaft – A GNU/Linux for the Raspberry Pi as an Andro... by lowtolerance on Sunday February 25, 2018 @02:40PM (#16460733)
Most cars don’t supply 12v thorough the accessory outlet when the ignition is off, so you’d need some of backup power source. Pis do not cope well with having the power cut off abruptly, so unless you want to carry a spare microSD card around at all times, you’d need some kind of solution for handling shutdowns.
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Re:Crankshaft – A GNU/Linux for the Raspberry Pi as an Andro... by TickleSteve on Sunday February 25, 2018 @06:32PM (#16461865)
That problem is simply because you're writing to the card continuously. Make your distro run from RAM and you're fine... that is what most embedded devices do, stick it all in an initramfs.
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Re:Crankshaft – A GNU/Linux for the Raspberry Pi as an Andro... by woolvalley on Sunday February 25, 2018 @02:50PM (#16460794)
A battery and something that detects the power has been cut off and does a shut down/standby.

Rpi startup takes a little while, so I don't know how nice it would be to wait 1 minute for your android auto system to startup.

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Re:Crankshaft – A GNU/Linux for the Raspberry Pi as an Andro... by thr0awaz on Sunday February 25, 2018 @07:32PM (#16462139)
It's not a big job to wire the detector you're talking about in your first sentence - it's more or less a relay and a capacitor (albeit a big capacitor, or maybe a battery if you put some more wiring and a charger in the circuit)

For the second one... you'd need to maybe consider tapping into the CAN bus and listening for a door unlock event, then powering up off that, and/or stripping everything out of the kernel and services that isn't needed... you could probably get that boot down to 10-15 seconds

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Re:Crankshaft – A GNU/Linux for the Raspberry Pi as an Andro... by bigiain on Sunday February 25, 2018 @09:08PM (#16462507)
Pretty sure he's already done that second part.

The linked "features demo" video on youtube shows it booting into the Crankshaft app from power on (through Rasbian Lite) in ~11 seconds.

https://www.youtube.com/watch?v=tFEpfuDBDjM&feature=youtu.be

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Re:Crankshaft – A GNU/Linux for the Raspberry Pi as an Andro... by rkangel on Monday February 26, 2018 @04:49AM (#16464220)
If you watch the video, the bootup time of the distro involved is significantly less than one minute - more like 10 seconds in fact.
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Re:Crankshaft – A GNU/Linux for the Raspberry Pi as an Andro... by askvictor on Sunday February 25, 2018 @08:19PM (#16462321)
I was quite surprised that my 2010 car does provide power through that outlet when it's off. What's your basis for saying _most_? I only have two datapoints myself, so can't generalise.
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Re:Crankshaft – A GNU/Linux for the Raspberry Pi as an Andro... by jackfraser on Tuesday February 27, 2018 @12:16PM (#16475531)
That's surprising. Seems like it would be easy to inadvertently drain your battery.
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Re:Crankshaft – A GNU/Linux for the Raspberry Pi as an Andro... by IshKebab on Monday February 26, 2018 @03:21AM (#16463925)
Mine too, from 2003. Stupid design, even then.
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Re:Crankshaft – A GNU/Linux for the Raspberry Pi as an Andro... by the-dude on Sunday February 25, 2018 @04:31PM (#16461273)
> Pis do not cope well with having the power cut off abruptly

Even with noatime?

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Re:Crankshaft – A GNU/Linux for the Raspberry Pi as an Andro... by Piskvorrr on Sunday February 25, 2018 @06:33PM (#16461868)
Even with the card mounted readonly. (Source: recent experience)
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