Rpi 4b in to Topping D10 for car audio (airplay)

[Ride154]

Hi there,

I'm new to Rpi's and all related.
Was looking for a airplay receiver in my car.
Just bought a 4B, installed moOde, tinkered a couple of hours with lots of reading on this forum and got it working.
Airplay via hdmi out works just fine.

Now for the next step!
I want to hook the Pi up to a Topping D10 with an optical cable to the dsp in my car.
But as soon as I connect the D10 the Rpi goes in a restart loop.
So ... what am I doing wrong here?
Or what should I read?

Greetings from Zandvoort, Menno!

[jonners]

Are you sure that your power supply is adequate for the RPi plus DAC and is not dropping below 5V during boot? In addition, if the RPi USB cannot supply sufficient power to the DAC you may need to use a powered USB hub.

[Miss Sissy Princess]

Are you sure that your power supply is adequate for the RPi plus DAC and is not dropping below 5V during boot? In addition, if the RPi USB cannot supply sufficient power to the DAC you may need to use a powered USB hub.

I think you're on the right track except for the Pi4 USB power capabilities. The USB power goes straight from power supply input of the Pi4 to the USB jacks.  The D10 is pretty low power (it's a DAC only, no headphone amp), so it shouldn't be a problem.

Less likely, but still possible explanations could be a noisy and/or poorly regulated power supply or a USB power cable is too small a gauge and/or too long, leading to excessive voltage drop due to cable resistance.

I'd drag an extension cord out to the car, use the official AC power supply, and verify that everything works that way.  If it does, then it's most likely what you said; the car power adapter.  I'd look at options from Anker.  I like the fact that they seem to design for safe failure modes (as opposed to some of the no-name Chinese adapters that fail by dumping ~13.7-14.7V going out to a 5V device).

[Jandu]

If you have a power bank in your procession, use it for temporary power supply to test if everything else works. Once that is done, you can still choose to use the power bank for your car, provided that you need to recharge it during your car trip by hooking it up to your cig lighter adapter or just use the power bank until it uses up the juices and swap it out with a charged one. 

My power bank has no problem providing RPi4B to Topping D10s to my DAC for headphone amp use, so likely D10 should work as well.

[Ride154]

Thx for the reactions!

At the moment I’m not testing in my car but with 240V and an iPhone power brick.
So I don’t think power is an issue but will change to iPad Pro charger just to be sure.
All cables used are about 2 feet, no idea about the gauge of the wire.
I’m using this funny cable as on and off switch and power cable.
https://www.123-3d.nl/123-3D-USB-C-kabel...16066.html

When MoOde is running and I attach the d10 and select the d10 in settings, it looks like its working.
The d10 says 44.1, but when I restart the pi I get the loop.
I can see command lines with numbers scrolling by but when lines that start with 4, it starts over again and again.
As I unplug the d10 the command lines pass the 4 and all is well.

For car use I have an Anker usb charger that is rated at 19W. (By anker that is)
And Topping says that the d10 uses less than 0,5A when using as usb to optical converter.
So I don’t think power is an issue but will use the iPad usb c power brick and a different usb c cable just to be sure.

Could the d10 be the issue?
In my current car setup no issues with the d10!
Update the d10? I’m not even sure these have an update available?

[TheOldPresbyope]

@Ride154

So

1) by itself, the RPi4B boots and runs successfully with the iPhone charger

2) once booted by itself, the RPi4B continues to run when the D10 is plugged into it

3) but the RPi4B won't boot successfully with the D10 already attached? 

To me, this suggests the iPhone charger isn't the right choice despite its rating. The reasons are complicated [1] but the bottom line is that you may not be supplying enough current for the RPi 4B's firmware to permit a full boot with the combination load.

Simplest test: try a different power supply, preferably the official Raspberry Pi USB-C power supply.

Regards,
Kent

[1] see, for example, RPiB USB C Power Delivery Negotiation as well as many, many blogs and reviews on the InterWeb™.

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. 

PS - I hope Zandvoort has been spared the flooding that has occurred elsewhere in the Netherlands this summer.

[Jandu]

Thx for the reactions!

At the moment I’m not testing in my car but with 240V and an iPhone power brick.
So I don’t think power is an issue but will change to iPad Pro charger just to be sure.
All cables used are about 2 feet, no idea about the gauge of the wire.
I’m using this funny cable as on and off switch and power cable.
https://www.123-3d.nl/123-3D-USB-C-kabel...16066.html

When MoOde is running and I attach the d10 and select the d10 in settings, it looks like its working.
The d10 says 44.1, but when I restart the pi I get the loop.
I can see command lines with numbers scrolling by but when lines that start with 4, it starts over again and again.
As I unplug the d10 the command lines pass the 4 and all is well.

For car use I have an Anker usb charger that is rated at 19W. (By anker that is)
And Topping says that the d10 uses less than 0,5A when using as usb to optical converter.
So I don’t think power is an issue but will use the iPad usb c power brick and a different usb c cable just to be sure.

Could the d10 be the issue?
In my current car setup no issues with the d10!
Update the d10? I’m not even sure these have an update available?

Try a bigger than 19W charger. I don't think you have enough juice

[Ride154]

@Ride154

So

1) by itself, the RPi4B boots and runs successfully with the iPhone charger

2) once booted by itself, the RPi4B continues to run when the D10 is plugged into it

3) but the RPi4B won't boot successfully with the D10 already attached? 

PS - I hope Zandvoort has been spared the flooding that has occurred elsewhere in the Netherlands this summer.

Correct! So more power it is!
I’ll start with the iPad charger for testing and when needed upgrade to the official power supply.
Will this still work in my car with a usb charger from the sig light thingie later if it needs that much power!?
We’re on the West Coast and not a drop of Rain here!
Beautiful beach weather.
The floodings are near the German border.
Really weird such a big differance in such a small country.
Thanks for caring!

[Ride154]

Try a bigger than 19W charger. I don't think you have enough juice

Thx!
More power it is!

[Ride154]

If you have a power bank in your procession, use it for temporary power supply to test if everything else works. Once that is done, you can still choose to use the power bank for your car, provided that you need to recharge it during your car trip by hooking it up to your cig lighter adapter or just use the power bank until it uses up the juices and swap it out with a charged one. 

My power bank has no problem providing RPi4B to Topping D10s to my DAC for headphone amp use, so likely D10 should work as well.

Which power bank are you using?
Or what specifications should I look for?