Power supply questions

[tkaiser]

Do you guys think it would be possible, or not too difficult, to get the Pine64 running in a car (by plugging it in through the cigarette lighter)? How would I go about doing this? Thank you for any help or resources.

Sure, any board with Allwinner SoC with PMU support + battery + stabilized step-down converter (something like this connected to the Euler pins) can do that.

[rahlquist]

Do you guys think it would be possible, or not too difficult, to get the Pine64 running in a car (by plugging it in through the cigarette lighter)? How would I go about doing this? Thank you for any help or resources.

What you are looking for is a DC - DC converter like this one perhpas;

http://www.ebay.com/itm/DC-DC-Adjustable...XQ74JTVyPL

I use one of those with my pine and a old laptop power supply.

[clamum]

Do you guys think it would be possible, or not too difficult, to get the Pine64 running in a car (by plugging it in through the cigarette lighter)? How would I go about doing this? Thank you for any help or resources.

Sure, any board with Allwinner SoC with PMU support + battery + stabilized step-down converter (something like this connected to the Euler pins) can do that.

Thank you (and rahlquist too). So it sounds like I'd need a DC-DC step down converter like you or rahlquist posted, and a battery (like this P64 RTC backup battery?) for when I shut my car off (although if it's gonna be off for hours I'd probably just power it down)?

Oh, just realized something. I'd also want an LCD screen in the vehicle as well. Hopefully I could power that from the cigarette lighter, too. I think my car has two of them (2011 Civic LX).

[tkaiser]

So it sounds like I'd need a DC-DC step down converter like you or rahlquist posted, and a battery (like this P64 RTC backup battery?)

Nope, in a car you need a stabilized step-down converter and you need a real battery (for the cases when input voltage drops below certain tresholds eg when you turn on the engine). Pine64 has a real battery connector not just for the RTC.

[rahlquist]

So it sounds like I'd need a DC-DC step down converter like you or rahlquist posted, and a battery (like this P64 RTC backup battery?)

Nope, in a car you need a stabilized step-down converter and you need a real battery (for the cases when input voltage drops below certain tresholds eg when you turn on the engine). Pine64 has a real battery connector not just for the RTC.

Thanks tkaiser, forgot about the inherent vast fluctuation in voltage in vehicles.

EDIT: A fairly comprehensive piece on this subject. 

http://www.carnetix.com/regulators/how_t...e_psu.html

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Overall I was just not thinking earlier. What you may want to do is find a stabilized supply that outputs more than 5v (say 9v) stable and the use a normal adjustable DC-DC converter for the final tweak since 5.0v may not be enough and you may need a smidge more depending on your situation and the length and quality of wires you use.

[tkaiser]

What you may want to do is find a stabilized supply that outputs more than 5v (say 9v) stable and the use a normal adjustable DC-DC converter for the final tweak

But that's what a stabilized step-down converter is for. And the additional 3.7V battery is for situations when the PMU decides that 5V DC-IN is insufficient (need not be that large since it's only about buffering temporary voltage drops). 

That's the nice thing when you use a SoC that is accompanied by a PMU with battery support. The PMU switches between different power sources on demand. That's why something like a Banana Pi or a Pine64 is superiour as car computer compared to something like a Raspberry or an Orange Pi since the former come with AXP209 or AXP803 and battery support. And that's all that's needed.

[clamum]

What you may want to do is find a stabilized supply that outputs more than 5v (say 9v) stable and the use a normal adjustable DC-DC converter for the final tweak

But that's what a stabilized step-down converter is for. And the additional 3.7V battery is for situations when the PMU decides that 5V DC-IN is insufficient (need not be that large since it's only about buffering temporary voltage drops). 

That's the nice thing when you use a SoC that is accompanied by a PMU with battery support. The PMU switches between different power sources on demand. That's why something like a Banana Pi or a Pine64 is superiour as car computer compared to something like a Raspberry or an Orange Pi since the former come with AXP209 or AXP803 and battery support. And that's all that's needed.

Man, you're an electrical haxor. I'm a software developer, and pretty comfortable with basic sysadmin and building computers, but I'm nearly completely ignorant of basic electronics and electrical topics.

Anyway, it looks like an 18650 battery is 3.7v; will one of those work? I have several rechargable ones laying around (for flashlights). And that converter you linked me to on Amazon should work hey? Nice and cheap too!

My car has only a single cigarette lighter. I wonder if it would be possible to buy one of those cigarette lighter -> USB plugs that goes into the cig lighter and gives you two USB ports. Then power the Pine64 and LCD touchscreen (I'm guessing the official 7" one from the P64 store) from that?

[peterz]

My car has only a single cigarette lighter. I wonder if it would be possible to buy one of those cigarette lighter -> USB plugs that goes into the cig lighter and gives you two USB ports. Then power the Pine64 and LCD touchscreen (I'm guessing the official 7" one from the P64 store) from that?

Yes, such adapters exists.

For example.
http://www.ebay.co.uk/itm/3-1-AMP-USB-IN...SwEK9T1feo

This particular gives you 5V and 3,1A (written on the product, reality might be different).
The better would be to buy from some reliable shop selling electronic things.

[clamum]

Well, I don't think I'm going to be putting my Pine64 in my car. Last night I found out/realized that it doesn't have GPS location support when I tried out the Google Maps app on it. Using it as a GPS in my car was going to be one of the main reasons for the project (I use my phone for navigation and checking traffic lot currently, in the car).

Ah well, will just have to find another project for it. ;-)

[SkimMilk]

Man, you're an electrical haxor. I'm a software developer, and pretty comfortable with basic sysadmin and building computers, but I'm nearly completely ignorant of basic electronics and electrical topics.

Anyway, it looks like an 18650 battery is 3.7v; will one of those work? I have several rechargable ones laying around (for flashlights). And that converter you linked me to on Amazon should work hey? Nice and cheap too!

My car has only a single cigarette lighter. I wonder if it would be possible to buy one of those cigarette lighter -> USB plugs that goes into the cig lighter and gives you two USB ports. Then power the Pine64 and LCD touchscreen (I'm guessing the official 7" one from the P64 store) from that?

I'm interested to know if a 18650 will work as a battery for the Pine too! Anyone?
BTW, what do you call those connectors for the wires and where can I get them?