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PiGRRL 2 with Pi 3 inside. Tips and good info.
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PiGRRL 2 with Pi 3 inside. Tips and good info.

by Raverrevolution on Tue Oct 25, 2016 10:36 am

First off I want to thank Adafruit for the PiGRRL 2 kit and for making this project fun to build.

Now I'm a Linux novice so I had to do a little bit of learning on the instructions to be able to make the PiGRRL 2 work with the Pi 3.

Before that I searched and searched and found absolutely no help to make anything easier. The best thing I had found was a locked thread here with someone posting a 16gb image that worked. The only con was that it was a painfully old version of Retropie and that since it was 16gb I couldn't easily back things up in case the SD card failed. On top of that the user that ripped the image must have used an odd SD card with more memory available, because I couldn't put it on any of my 16gb cards.

So at the risk of this thread being locked and me being banned I present the public with this;

A 4gb PiGRRL 2-Pi3-Retropie 4.0.4 image.

https://drive.google.com/open?id=0B0htQ ... FU2RUt6VUk

Please Adafruit!! Keep this up so people don't have to search far and wide since it's just about impossible to find Raspberry Pi 2s anymore.

Secondly, to get rid of all audio interference you do this;

1)Wrap the battery in copper tape and then electrical tape. Then you solder a wire from the ground of the audio circuit to the copper. It helps to solder to a random piece and then stick it to the battery so you're not soldering on the battery itself as it's dangerous.

2)Buy tiny ferrite beads and put them around the speaker wires. Ferrite beads provide EMI shielding and putting them around the speaker wires worked like a charm.

My PiGRRL 2 is completely silent now until a game plays.

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Re: PiGRRL 2 with Pi 3 inside. Tips and good info.

by adafruit2 on Mon Oct 31, 2016 9:59 pm

neat! thanks for the image and tips
we were just finishing up a pi 3 -compatible image with retropie 4.0
do you mind trying it?

https://adafruit-download.s3.amazonaws. ... -10-31.zip

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Re: PiGRRL 2 with Pi 3 inside. Tips and good info.

by Raverrevolution on Tue Nov 01, 2016 4:07 pm

Definitely tonight I'll try it out.

I have ran into a recent problem though, maybe someone can help.

It turns out that in the latest versions of Retropie you can install Kodi as another system from the list. With my original image Kodi won't load. My original image is fine and to spec. It also accomplishes what it needs to do as Kodi is above and beyond at this point.

I figured out that if I played with the config.txt file and commented out "hdmi force hotplug=1" it would boot albeit look a little off, but then it would boot into Kodi!!

From here I've been trying to figure out a good way to control Kodi as the on board controls do nothing. If you plug in a mini keyboard it's all good to go.

I've toyed with the option to add a joystick.xml file to the Kodi keymaps folder, but nothing, not working.

Next I toyed with enabling touchscreen controls since we are using a touchscreen in the kit which would be awesome if worked well. These don't work either. If I touch the very very bottom left of the screen you'll see the mouse cursor on the very right bottom. I think this has to do with the pitft resolution and Kodi's resolution not wanting to shake hands with each other.

I will try to pry more into this tonight and see what can be done.

Thank you Adafruit! I absolutely love this machine that I built

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Re: PiGRRL 2 with Pi 3 inside. Tips and good info.

by Raverrevolution on Wed Nov 02, 2016 9:26 am

adafruit2 wrote:neat! thanks for the image and tips
we were just finishing up a pi 3 -compatible image with retropie 4.0
do you mind trying it?

https://adafruit-download.s3.amazonaws. ... -10-31.zip


The image works great!! Tried it last night.

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Re: PiGRRL 2 with Pi 3 inside. Tips and good info.

by Ratdadjoe on Sat Nov 05, 2016 1:27 am

Raverrevolution wrote:2)Buy tiny ferrite beads and put them around the speaker wires. Ferrite beads provide EMI shielding and putting them around the speaker wires worked like a charm.

My PiGRRL 2 is completely silent now until a game plays.


You may find you don't need to "buy" a ferrite bead if you are a packrat. I hoard micro USB phone charger cables that are broken. Usually, it's the micro end that gets messed up. People step on them, they drop their phone while it's plugged in, stretching out the thin metal housing, etc. The cable is still useful for other things. USB A plug end is usually still good, and the couple feet of 28ish sized wires, and usually, a shiny ferrite bead! Just be careful cutting away the overmoulding around the bead, it's tough stuff! A bead I scrounged is what I intend to use on my Pi Grrl 2. I'm also going to try your idea with the the copper tape, it seems it would work well.

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Re: PiGRRL 2 with Pi 3 inside. Tips and good info.

by Raverrevolution on Mon Nov 07, 2016 5:45 pm

The thing is that there will always be some type of hiss regardless, but it's so low and much better than any noise. I never get the machine gun sounding noise anymore which I'm really happy about.

Whenever you start playing a game it sounds great though.

I know there is one method of lowering the screen refresh rate and yes it does work, but personally I couldn't stand the lowered frame rate. It's very noticeable when you're used to the default being higher.

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Re: PiGRRL 2 with Pi 3 inside. Tips and good info.

by dj153 on Thu Nov 10, 2016 12:33 pm

Raverrevolution wrote:Secondly, to get rid of all audio interference you do this;

1)Wrap the battery in copper tape and then electrical tape. Then you solder a wire from the ground of the audio circuit to the copper. It helps to solder to a random piece and then stick it to the battery so you're not soldering on the battery itself as it's dangerous.

2)Buy tiny ferrite beads and put them around the speaker wires. Ferrite beads provide EMI shielding and putting them around the speaker wires worked like a charm.

My PiGRRL 2 is completely silent now until a game plays.



Hello,

I also built a PiGRRL 2 myself sometime ago, but that awful speaker noise caused by the battery was really a fun-stopper for me. So I put it aside in hope finding a solution sometime. Maybe this time is now thank to your efforts.

I'm really looking forward to try this myself. Maybe you can give me some more technical details about the stuff you used. Maybe it doesn't matter at all and you can use any model, but I'm trying to avoid buying things twice.

So what kind of copper tape did you use? Does it matter how thick it is? Should it be self-adhesive? Did you solder the copper before you wrap the battery in that electrical tape?

About the ferrite beads I'm even more confused if there are any important technical specifications which should be considered?

It would be great if you could give me some advise.

Thank you very much, I'd really appreciate your reply.

David

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Re: PiGRRL 2 with Pi 3 inside. Tips and good info.

by Ratdadjoe on Wed Nov 16, 2016 2:02 am

dj153 wrote:
Hello,

I also built a PiGRRL 2 myself sometime ago, but that awful speaker noise caused by the battery was really a fun-stopper for me. So I put it aside in hope finding a solution sometime. Maybe this time is now thank to your efforts.

I'm really looking forward to try this myself. Maybe you can give me some more technical details about the stuff you used. Maybe it doesn't matter at all and you can use any model, but I'm trying to avoid buying things twice.

So what kind of copper tape did you use? Does it matter how thick it is? Should it be self-adhesive? Did you solder the copper before you wrap the battery in that electrical tape?

About the ferrite beads I'm even more confused if there are any important technical specifications which should be considered?

It would be great if you could give me some advise.

Thank you very much, I'd really appreciate your reply.

David


I built mine... Did the ferrite bead, did the copper foil wrap on the battery with the wire to ground on the amp... It was OK, but sometimes, I'd still get noise in the speaker. Not just a dull analog "hiss" (you are going to get no matter what) but some high frequency interference here and there. I twisted the speaker wires really good, and wrapped them in copper foil, and put a layer of kapton tape over the top to insulate it. I also put a layer of kapton on the amp, and a small square of copper foil over that, and another layer to seal it up. Now I only get a very low analog hiss when I'm in the menus. This is acceptable to my OCD... :P

I think you could probably quiet it down a bunch just by shielding the speaker wires and amp like I did. I'm not really sold on the what the battery wrap and ferrite bead was giving me. Any metal foil would work, even the aluminium kind used in cooking. The conductive copper tape was just on hand, and the sticky back made it easy to work with. No matter what you use, take care to seal it away from touching the electronics with some kapton or electrical tape.

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Re: PiGRRL 2 with Pi 3 inside. Tips and good info.

by Raverrevolution on Wed Nov 16, 2016 10:20 am

The ferrite bead and copper tape worked well for me.

I had originally tried wrapping the battery in aluminum foil and sometimes I would be lucky and get no noise, but other times I'd get a ton of interference.

I then tried the piece of copper tape onto the aluminum and a wire going from that to the ground of the amp and it did literally nothing. I felt like no matter who's instruction I used it barely helped or did nothing.

Lowering the screen's refresh rate was the only sure thing that helped. You'll get no noise despite what you wrapped the battery with. The only issue then comes the frame rate in games which is acceptable to many, but bothered me. Games just didn't feel as fluid.

So then I was like F it!! I'll just literally apply everyone's fix at once, but add copper which is supposed to be a better shielding metal and ferrite beads which are made for shielding components from EMI and boom, no extra random sounds for me.

Be aware that I do get a hiss. I feel like it's inevitable to get that. The hissing though is really really not that bad at all especially when you start a game to then which the music takes over it all.

Sorry dj153 that I didn't respond sooner, but these are the items I used and where I got them;

Copper tape - http://www.ebay.com/itm/141822339796?_t ... EBIDX%3AIT What I did was solder the wire to a piece of the tape first. Then I wrapped the battery and in the end stuck the wired piece to the rest of the wrap.

Ferrite beads - http://www.ebay.com/itm/201588447779?_t ... EBIDX%3AIT These seemed to have fit very snug around the speaker wire that comes with the speaker. With ferrite beads you don't want them to be super loose.

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Re: PiGRRL 2 with Pi 3 inside. Tips and good info.

by YeeP on Fri Dec 07, 2018 6:27 pm

Sorry to bring this back from the dead but I have never used ferrite beads before. Do I need to line the wires with them, or is it just one per wire?

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Re: PiGRRL 2 with Pi 3 inside. Tips and good info.

by adafruit_support_mike on Sat Dec 08, 2018 2:24 am

Nope, just run the wire through them.

Every path with current flowing through it has a magnetic field around it, and magnetic flux likes to flow through ferromagnetic materials the way electrons like to flow through metal. When you put a ferrite bead around a wire, almost all of the magnetic flux in that region will go into the ferrite because that's the path of least magnetic resistance (or 'highest permittivity' to use the official term).

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