deindichter
Posts: 11
Joined: Wed May 27, 2020 7:07 pm

Car pi question

Thu May 28, 2020 8:20 pm

Greetings all,

I am wanting to use my speakers in my car for my raspberry pi 4 I am planning to install in the dash of my car. I have a product that takes the stock wiring harness and converts it to plugs I can use to power the pi, also it provides the +,- leads for each of the speakers, and steering wheel controls too. I want to take these +,- leads and use them to play sound in my car. How would you suggest this can be accomplished.

https://www.caraudiogiants.com/product/ ... n8EALw_wcB is the part I'm describing that I have.

Things I have considered, what do you think?

splicing the positive and negative wires to the positive and negative of an RCA, and then trying to find a multiple channel rca adapter that will convert that to auxiliary or another usable format that can be run to the PI.

I considered using https://www.adafruit.com/product/935, but am not totally sure how I would use this for the given task.

deepo
Posts: 574
Joined: Sun Dec 30, 2018 8:36 pm
Location: Denmark

Re: Car pi question

Fri May 29, 2020 12:13 pm

Does the interface box contain an amplifier?
If not, then you need an amplifier.
The Raspberry Pi can't drive speakers by itself.

/Mogens

deindichter
Posts: 11
Joined: Wed May 27, 2020 7:07 pm

Re: Car pi question

Sun Jun 21, 2020 1:29 am

Greetings again,

I do not believe it contains an amplifier, it simply has +/- leads that extend the radio wiring harness that is stock. In that case what kind of amplifier would work?

After reading your reply, something like this maybe:
https://www.hifiberry.com/products/ampplus/?amp

Are there any options anyone can think of that could be powered without having to connect to all GPIO pins? I ask because I want to use the pins to listen for steering wheel control commands, also I have my touchscreen already attached to two of the pins which is powering it.

Does anyone know of an option that could be powered by the pi 5V pin, or other option that would avoid having to mount it directly to the pi?

Thank you Deepo for your original response, sorry for the delay.

deindichter
Posts: 11
Joined: Wed May 27, 2020 7:07 pm

Re: Car pi question

Sun Jun 21, 2020 5:14 pm

Additional question, If I would buy a hifiberry or another similar 'hat' for my PI, would I lose access to the GPIO pins or are they extended to the top of the next tier created with the hifiberry2. because I need somehow to have a place to put my steering wheel control and listen for voltages, additionally I need somewhere to put my 5v plug and ground for the screen.

pidd
Posts: 250
Joined: Fri May 29, 2020 8:29 pm
Location: Wirral, UK

Re: Car pi question

Sun Jun 21, 2020 5:47 pm

You can put HATs above and below the pi if you use the appropriate header.

deindichter
Posts: 11
Joined: Wed May 27, 2020 7:07 pm

Re: Car pi question

Sun Jun 21, 2020 8:42 pm

https://www.amazon.com/HiFiBerry-Hifibe ... ics&sr=1-1

This thing has a 12v power supply and claims it will power the pi as well, but customer service says it could probably power the touchscreen but anything more than that it would not have ample power. Initially, before ever thinking about the Amp I bought a buck converter and was planning on powering the pi from my power while car is powered on. Do you think there's a possibility that I could power each independent of each other but still get the functionality of the amplifier?

Basically I have a wiring harness that extends my steering wheel controls, speakers, Navi if I had any, backup cam and power. This device does not seem to have an amplifier, so in order to power these speakers are there any solutions anyone can think of? I thought maybe convert them to RCA then to HDMI. you can force linux to play sound through HDMI. Does this seem like a workable solution.

Pardon my ignorance, I am just doing this as a way to learn but its a learning curve for me.

deindichter
Posts: 11
Joined: Wed May 27, 2020 7:07 pm

Re: Car pi question

Sun Jun 21, 2020 8:56 pm

pidd wrote:
Sun Jun 21, 2020 5:47 pm
You can put HATs above and below the pi if you use the appropriate header.
Can you give me an example of what you mean? Thank you.

DarrenHill
Posts: 253
Joined: Fri Oct 03, 2014 3:03 pm

Re: Car pi question

Mon Jun 22, 2020 4:08 pm

Something like this may be what you need:

https://shop.pimoroni.com/products/mini ... 9448025991

Just remember that the HATs won't be able to share pins (other than power and ground), with the exception of the i2c pin as long as they have proper set-ups with different addresses.

pinout.xyz is a good site to know which HATs use which GPIO pins.

If you are mounting HATs underneath the Pi, remember to make sure you solder the header connectors correctly so that you don't end up mirroring the pin connections. This would be especially "fun" for HATs that come with pre-soldered headers.

pidd
Posts: 250
Joined: Fri May 29, 2020 8:29 pm
Location: Wirral, UK

Re: Car pi question

Mon Jun 22, 2020 4:23 pm

deindichter wrote:
Sun Jun 21, 2020 8:56 pm
pidd wrote:
Sun Jun 21, 2020 5:47 pm
You can put HATs above and below the pi if you use the appropriate header.
Can you give me an example of what you mean? Thank you.
I can't find the picture of what I meant but basically you have long pins going through the pi and put a header socket on the top of the lower HAT. Pin 1 will still go to pin 1 etc.

Some years ago I thought the intention of the pi was to have stacked HATs (albeit perhaps not above and below)

User avatar
rpdom
Posts: 17004
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: Car pi question

Mon Jun 22, 2020 5:10 pm

pidd wrote:
Mon Jun 22, 2020 4:23 pm
Some years ago I thought the intention of the pi was to have stacked HATs
There was some consideration put into stackable HATs in the early days, but there were too many possibilities of conflicts on GPIOs and the fact the eeproms would need different addresses.

The PoE HAT is the only official HAT that is stackable at present. It does use a different address for its eeprom and as it only uses i2c and power it can coexist with other HATs.

Boards that don't use the HAT standards may be stackable.
Unreadable squiggle

deepo
Posts: 574
Joined: Sun Dec 30, 2018 8:36 pm
Location: Denmark

Re: Car pi question

Mon Jun 22, 2020 8:47 pm

The type of connector used on the SparkFun Qwiic HAT for Raspberry Pi seems to be able to put something in between the Raspberry Pi and a HAT.
But I don't know if it's used in any usable (to your needs) products.

DarrenHill
Posts: 253
Joined: Fri Oct 03, 2014 3:03 pm

Re: Car pi question

Tue Jun 23, 2020 3:47 pm

@pidd - an extender or riser header:

https://shop.pimoroni.com/products/male ... 7338113107

Same as a normal header but with longer pins, to allow stacking or through connection for suitable HATs if you're careful and good at soldering.

deindichter
Posts: 11
Joined: Wed May 27, 2020 7:07 pm

Re: Car pi question

Sat Jun 27, 2020 8:53 pm

Greetings all again,

Thank you for the support. So I have managed to make some progress, I appreciate the education on header, it was as I thought I just wanted to confirm.

My Pi sound is being broadcasted via a USB sound card that is attached to the pi, and an aux cable spliced into my speaker wires, the sound is good enough but too lo with a/c on and other distractions in the vehicle.


I am going to buy a https://learn.adafruit.com/adafruit-max ... -mono-amp/.

My next dillema is how to get all these moving parts attached to one place so I can avoid grounding anything, and additionally make it cleaner and easier to place inside the dash. I see lots of "bread boards" but that seems for prototyping, What I ideally want is a board that will not short the devices, but will mount everything together in one place. The dash cavity is roughly 9 in x 5in. Can anyone identify or clarify how I can solve this issue. Thank you guys!

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