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Rpi 4b in to Topping D10 for car audio (airplay)
#11
Or is there a way to hook it up to my 14.4V car audio fusebox?
And somehow stepdown to 5V
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#12
(07-18-2021, 04:35 PM)Ride154 Wrote: [quote pid='35366' dateline='1626538263']
Which power bank are you using?
Or what specifications should I look for?
[/quote]

https://www.buyapi.ca/product/compact-re...-10400mah/
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#13
(07-18-2021, 04:52 PM)Ride154 Wrote: Or is there a way to hook it up to my 14.4V car audio fusebox?
And somehow stepdown to 5V

Yes, there is---more than one, actually. 

One possibility is to get a bucking-type converter which takes the auto supply voltage and "bucks" it down to 5v DC. DROK is one brand I happen to know about but there are many others.

Another is to get an inverter which takes the auto supply voltage and "inverts" it to 120v or 240v AC (nominal). Then a normal Raspberry Pi AC power pack can be used to convert this to 5v DC. 

The latter scheme sounds crazy but I've done it when I had a temporary need and had a inverter gathering dust on the shelf where my significant other's son had left it when he went to college.

I'm sure others can suggest more possibilities.

I'd recommend that in all cases the attachment be made on a line which switches off when the ignition is turned off. Otherwise you might suffer the ignominy of needing a jump start if and when the battery is drained so far that the engine can't be restarted from it. (Don't ask me how I know!)

Another consideration is that auto electrical supply is notoriously noisy (and so is the usual inverter), so extra filtering may be required at the RPi power-input end of things.

Glad to hear you are dry. I've been in the Amsterdam/Rotterdam/Delft triangle a number of times but never made it over to the coast. Many, many decades ago, I lived for a time in Wiesbaden, Germany. The images of the flood damage in areas west of there make me sad.

Regards,
Kent
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#14
So did a bit of testing today.
And the Rpi works better with the standard iPhone than the newer bigger iPad pro charger.
That bigger charger says 20 Watts and 5V with 3A's
I looked at the official wall wart for a Pi and that says 15 W and 5V and 3A's.
The iPhone charger is usb A and the iPad charger is usb C.

With the same specs that charger should work, yes?
It doesn't even start up with the bigger charger, wtf!
Is Apple lying with the specs on their chargers?
Or do I have one of those Pi's as suggested by Old P?

[ As an aside, it is well known that the original version of the RPi 4B lacks critical resistors in its USB-C interface and, specifically, wouldn't boot with iPhone USB-C chargers. This was corrected in a later board version. I don't think this is the specific cause of your issue since your RPi4B by itself boots with your iPhone charger, although this may be only because of the "funny" cable which likely isn't e-marked. ]

Time for an official Pi wall wart!
I'll report back when thats in.
At the moment I doubt that this is ever going to work in my car.
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#15
@Ride154

As I hinted (fairly strongly, I thought) before, USB-C power negotiation is a tricky business and raw voltage/amperage/wattage numbers don't tell the whole story.

For the car installation, you might look into offerings such as this Mausberry supply

And, candidly, this is not really the right forum for these questions. To reach more birds of a feather, I'd try either the Raspberry Pi Forum or something like the Car Audio forum at diyaudio.com.

Good luck.

Regards,
Kent
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#16
That will do the trick!
Thx
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#17
@Ride154

Just one more consideration.

1) the RPi4B runs hotter than previous models.

2) the RPi4B starts throttling when the CPU temperature reaches about 80C (ref https://www.raspberrypi.org/documentatio...agement.md). NOTE - that's an internally sensed temperature, not a case temperature.

3) in my tests of an RPi4B in an Argon 40 Case taking advantage only of its passive cooling solution, I see the CPU temperature reported by the RPi's firmware is already roughly 15C higher than ambient air temperature with moOde 7.3.0 running at idle. Jeff Geerling has reported in his blog that his RPi4B in the same case never got more than roughly 40C above ambient under his max-load test.

4) given the conditions in a car's interior on a hot day before the A/C has done its job, I suspect one needs passive cooling at least as good as that provided by the Argon case, especially if the RPi is tucked away somewhere. Of course there are also active, fan-based cooling solutions available, including the fan built into the Argon case (which I don't bother with at home).

Regards,
Kent
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#18
was wondering 'bout that.
Thx
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#19
A Pi4 for the separation of USB and network....with an Argon-One case for passive cooling...(no fan needed.)

Works for the very low overhead from MoOde .....perhaps 5-10% cpu usage...sweet! :-)
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bob
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#20
Can you look at the temp somewhere in moOde?
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