Pi5 wifi unusable

[Steven Hirsch]

I realize this is not a forum for RPi issues, but since many of us are using the Pi 5 with their PiDP-10 I'm curious about experiences with poor wifi connectivity.  Mine is absolutely useless.  Following some comments about interference from nvme hats, I removed the Pimoroni and booted from SD card.  Didn't make any difference.  I'm unable to connect on either band despite being only 15 feet from the router.  None of my other Pi units (not 5s) have the slightest difficulty.  I've tried all the suggestions online, checked region settings, etc, etc.  Nothing makes a difference.

Am I alone in experiencing this?

[Whit Turner]

I've had no issues with the Pi 5 in my PiDP 10. Mine is about 25 feet from the router on a different house floor. The router is an Xfinity box which sits inside a wooden cabinet. Perhaps a defective PI?

Whit

[Steven Hirsch]

Are you saying that I shouldn't be seeing wpa_supplicant running?  It appears in 'ps' output in addition to NetworkManager.  In contrast to the article you linked, I am finding configuration files under /etc/wpa_supplicant.

[Mike Kostersitz]

Interesting, are you not running bookworm?

---

From: pid...@googlegroups.com <pid...@googlegroups.com> on behalf of Steven Hirsch <snhi...@gmail.com>
Sent: Tuesday, July 16, 2024 8:56 AM
To: PiDP-10 <pid...@googlegroups.com>
Subject: [pidp-10] Re: Pi5 wifi unusable

 

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[sunnyboy010101]

I posted my issues in the NVME thread, but thought I'd post my solution here as well.

Brief update first; I have two almost identical PI5 setups - one with a top m.2 board and a new one with a bottom m.2 board. The top m.2 has been working (with wifi) without issues 24/7 since mid-June. The new one would work but then wifi would just cut out after a couple of minutes. I found last evening that plugging in the network port worked as expected, but also made the wifi work. More curious, if I unplugged the wired lan, the wifi quit instantly. Plug it back in - wifi came up instantly.

I had read elsewhere that some people were having issues with NVME m.2 'hats' on some Pi5 setups giving the same wifi issues. As both m.2 hats were the same manufacturer and possibly the same chip, it seemed odd that one would have issues but not both.

So I re-checked all the parameters and found a problem: the new board's instruction pamplet said to add "dtparam=pcie1x" while the working pi5 had  "dtparam=pciex1". I checked on the official Raspberry Pi documents online, and the parameter was indeed pciex1. (love those bad pamplets). I changed the new board to the correct parameter, and added the "tdparam=pcie1x_gen=3" as well (recommended for this new board) and after rebooting - WIFI worked properly. As both boards were same manufacturer I added the gen=3 parameter to the first board as well.

As of 12 hours later, both boards are still running wifi without any issues.

[Dennis Boone]

> I realize this is not a forum for RPi issues, but since many of us
> are using the Pi 5 with their PiDP-10 I'm curious about experiences
> with poor wifi connectivity. Mine is absolutely useless. Following
> some comments about interference from nvme hats, I removed the
> Pimoroni and booted from SD card. Didn't make any difference. I'm
> unable to connect on either band despite being only 15 feet from the
> router. None of my other Pi units (not 5s) have the slightest
> difficulty. I've tried all the suggestions online, checked region
> settings, etc, etc. Nothing makes a difference.

On a Pi 5, the wifi antenna is a PCB gimmick arrangement. Find the
triangle next to the Pi bus header, the silver-topped wifi chip, and the
PCIe ribbon connector.

Various things could degrade signal strength or antenna pattern by being
in the near field: an active cooler, a hat mounted top or bottom, a PCIe
cable, etc. The wavelength of a 5.8 GHz wifi signal is around 2", for
2.4 it's about 5". The transition zone between near and far field seems
to be defined as about 1 wavelength out from the antenna.

My PiMoroni NVMe board's PCIe cable will definitely be in the pattern of
the antenna. By contrast, the official RPi one seems to keep its cable
in the center of the board, so might be better.

Positioning of the Pi relative to the access point could have a
significant impact even without coolers or hats. Try fiddling with
orientation. Also note that there are four microscopic surface mount
components in that triangle antenna area, two in mid-triangle, and two
right at the edge of the board. If one were to have rubbed them a bit
firmly in handling while mounting stuff to the Pi or the Pi to the real
machine (tm), and they were now missing, the antenna impedance match
would be way off, making it far less effective than even its normal
feebleness.

If you want an explanation of the antenna type used here (theory,
diagrams, Smith charts &c) see:

https://www.antenna-theory.com/design/raspberry-pi-antenna.php

The second image on that page has a blowup of the monoband antenna on a
Pi 3, where you can see the sort of components I mentioned above.

De

[Steven Hirsch]

On Tue, 16 Jul 2024, Mike Kostersitz wrote:

> Interesting, are you not running bookworm?

I'm running Debian 12.5, aka Bookworm. Am I not supposed to be seeing the
wpa_supplicant process?



>
> ________________________________________________________________________________________________________________

[Steven Hirsch]

Thanks for all the responses and advice, folks.  Unfortunately none of this worked for me.  To go point by point:

• To eliminate the nvme hat as a source of trouble, I removed it completely and ran from a freshly built (by Pi Imager) SD card.
• The little coupling capacitors are definitely in place and undisturbed.
• I tried switching to 5 GHz, but it wouldn't even connect on that band, much less pass packets.
• I tried moving the board around and raising it up in the air to avoid interference from other items on the table top.
• Double-checked all settings per RPi troubleshooting docs.

Nothing helped.  The unit connects immediately to the access point on the 2.4GHz band and receives an IP address from DHCP.  Even though nominally connected, it exhibits between 75 and 90% packet loss and is effectively unusable.

I contacted the Pi Shop for help and am working through their troubleshooting points - none of which have changed the behavior one iota. I'm hoping they will exchange it for a working board.

[Shawn Goodin]

Are the localization settings correct?  There's one there for WiFi (presumably slightly different band frequencies in different countries.

sudo raspi-config  may have a setting for that.

Shawn Goodin

To view this discussion on the web visit https://groups.google.com/d/msgid/pidp-10/a074e1ad-2510-4f47-b4d3-76666bc9aac5n%40googlegroups.com.

[Steven Hirsch]

On Wed, 17 Jul 2024, Shawn Goodin wrote:

> Are the localization settings correct? There's one there for WiFi
> (presumably slightly different band frequencies in different countries.

Yes, that's part of the RPi connectivity checklist.

>
> sudo raspi-config may have a setting for that.
>
> Shawn Goodin
>
> On Wed, Jul 17, 2024, 1:12 PM Steven Hirsch <snhi...@gmail.com> wrote:
>
>> Thanks for all the responses and advice, folks. Unfortunately none of
>> this worked for me. To go point by point:
>>

>> - To eliminate the nvme hat as a source of trouble, I removed it

>> completely and ran from a freshly built (by Pi Imager) SD card.

>> - The little coupling capacitors are definitely in place and
>> undisturbed.
>> - I tried switching to 5 GHz, but it wouldn't even connect on that

>> band, much less pass packets.

>> - I tried moving the board around and raising it up in the air to

>> avoid interference from other items on the table top.

>> - Double-checked all settings per RPi troubleshooting docs.

[sunnyboy010101]

Well, interestingly I'm back where I was before - this pi5 loses it's wifi almost instantly unless a network cable is plugged into the RJ45 jack. Unplug - lose wifi (instantly); plug back in - wifi back.

I'm sure it has to do with this particular back mount NVME card but I don't care anymore. It works.

I did a fair bit of troubleshooting; built new SD card from scratch and copied to NVME (no difference). Even copied working system NVME to SD card, then over to new pi5, copied and cloned to NVME, such that the systems were virtually identical. Exact same behavior. I therefore conclude it's the NVME (m.2) card, but as I'm not changing it I will live with a wired PiDP10.

[Steven Hirsch]

After I demonstrated the problem, the Pi Shop exchanged my Pi5 for a new unit.  Damned if it didn't do exactly the same thing!  Numb and dumb on the 2.4GHz wifi band.  After banging my head against the wall for a while, I calmed down and started troubleshooting in earnest.  Turned out to be interference from the HDMI cable!  I'm using what I thought was a quality cable, but apparently not so much.  If I boot the board without the monitor connection it acquires an IP address from the access point very quickly with decent signal quality.  Then, while watching wavemon running through an ssh session I plug the cable in.  Connectivity goes to straight to hell almost instantly and it becomes unusable.  Doesn't seem to matter whether I use port 0 or 1. 

At this point I'm looking for recommendations on a micro-to-HDMI cable with better shielding.  Can someone who is successfully using a Pi 5 with Wifi only networking along with HDMI tell me what they have for cabling?  What I'm seeing is not subtle and occurs instantly on connection.  I believe the Pi folks are aware of this, but aren't going to create problems for themselves by owning up to it.

[Ian Schofield]

Hi All,

 I have seen this and it is a complete pain. This was originally reported for the PI4 in that certain HDMI resolutions stuffed the wifi.

 I do think that the active cooler doesn't help either.

 I've given up and connected to my PI 5 in the PiDP10 over VNC. I haven't gone through all the HDMI resolutions to see if any of them are OK.

 This would be a bit of a kludge and given the graphics over VNC are not bad, I will stick with this.

 The alternatives are to use a wired network or a WIFI dongle on the end of a USB cable?????

[Logimancer]

FWIW, I’ve noticed some issues as well. It’s useable, but I have noticed more disconnects and dropouts vs any other sbc board I’ve used. I’ve probably have at-least 20 lying around (don’t ask) and the pi5 has been worse than the rest. Granted, I got it for the pipd-10, and I didn’t use it much without it. I haven’t done any tests, but if I was to hazard a guess, it’s either interference related or the pi5 antenna isn’t that great. Very much just an intuition thing though, and intuition isn’t worth much when empirical results aren’t too difficult to obtain. ;)

On Jul 27, 2024, at 17:16, Ian Schofield <isy...@gmail.com> wrote:

Hi All,

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[Ken Hansen]

Wasn't there an issue with HDMI interfering with WiFi? It sounds real familiar, and as I recall it's fixed with a firmware update.

Have you updated the RPi firmware?

Ken

On Jul 27, 2024, at 16:16, Ian Schofield <isy...@gmail.com> wrote:

Hi All,

--

[Steven Hirsch]

I'm glad it isn't just me...  I have several Pi 3s and Zeros here.  None of them exhibit the problem.  You can be sure that the Pi developers know about this.  I'm keeping my fingers crossed that it can be corrected in software.  If it's a hardware issue I'd expect a Pi 5B to appear soon with no admission of the problem.

I tend to agree with your take on the antenna as well.  It's not helping matters.

[Steven Hirsch]

The first thing I did was update the firmware.  It's running a version that's about a week old.

[sunnyboy010101]

In my case I have two Rpi5's that are as identical as can be w.r.t. software - I cloned the first one to the second. The first Rpi5 works perfectly with just WIFI. It's been on since mid-June without any issues. Wifi on the second one only works if there is a wired internet plugged in. If I unplug the network, wifi quits. If I plug it back in, wifi comes back.

The only difference between the two is the type of NVME m.2 board. Otherwise, both rpi5's were purchased identical configuration and bought from the same company (Canakit), both have the identical cooler, both have the identical NVME SSD (Patriot 256GB). One is in a case and the other (wifi issues) is now mounted on my PiDP10.  The good one has a top mounted NVME 'hat' while the other has a bottom mounted NVME 'hat' , necessary so I could plug it into the PiDP10 without issues.

The wifi issue has been consistent and permanant - that is it hasn't gone away no matter what - even tried new Raspbian config before cloning the 'good' one.

I did read that there was some issue with bottom mount hats, and I note they do contact the GPIO connector via push-pins instead of a solid plug (top mount) but no amount of fiddling has changed the situation.

I have simply decided it's something I can live with for now. It means two cables to the bookshelf holding my PiDP10 (power & NIC) but that's OK.

[Michael Harpe]

For what it's worth, I have had very bad luck over the years with smaller HDMI connectors. The connectors themselves are usually very flimsy. I had one on a graphics card that basically wore out prematurely. Micro apparently is going to be the same way.

I am not crazy about the Pi 5 anyway. Those pinch ribbon connectors are quite flimsy.

Michael Harpe

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[Steven Hirsch]

Ok, more cycles burned here...   With the HDMI cable pulled my connectivity problems went away.   But they returned with a veangence after re-installing a Pimoroni Nvme piggyback.  I'll leave out the shameful language and angst that resulted, but long story short I now have it back in operation.  What did the trick was switching to a longer ribbon cable between nvme and Pi 5, increasing the separation between Pi and piggyback to 12mm and, most importantly, replacing the Pimoroni metal standoffs and hardware with nylon parts.  Bottom line:  The onboard antenna on the Pi5 is a seriously flawed design that's greatly affected by anything conductive or reflective in its immediate vicinity.  I'm now getting a usable remote VNC session!  I also have a couple of high-quality micro-HDMI to HDMI cables on the way with ferrite core at the micro end.  I'm not holding out much hope, but possibly this will mitigate against the RFI issues.

I'm sure we are not the only folks experiencing Pi 5 Wifi issues and I have little doubt there will be a redesign in the near future.

[Steven A. Falco]

On 7/28/24 10:50 AM, Steven Hirsch wrote:
> Ok, more cycles burned here...   With the HDMI cable pulled my connectivity problems went away.   But they returned with a veangence after re-installing a Pimoroni Nvme piggyback.  I'll leave out the shameful language and angst that resulted, but long story short I now have it back in operation.  What did the trick was switching to a longer ribbon cable between nvme and Pi 5, increasing the separation between Pi and piggyback to 12mm and, most importantly, replacing the Pimoroni metal standoffs and hardware with nylon parts.  Bottom line:  The onboard antenna on the Pi5 is a seriously flawed design that's greatly affected by anything conductive or reflective in its immediate vicinity.  I'm now getting a usable remote VNC session!  I also have a couple of high-quality micro-HDMI to HDMI cables on the way with ferrite core at the micro end.  I'm not holding out much hope, but possibly this will mitigate against the RFI issues.
>
> I'm sure we are not the only folks experiencing Pi 5 Wifi issues and I have little doubt there will be a redesign in the near future

I found an article about the Pi antenna designs that might be of theoretical interest - won't solve any problems for folks though:

https://embeddedcomputing.com/technology/analog-and-power/power-semiconductors-wireless-charging/a-lesson-in-wireless-engineering-from-the-raspberry-pi

I think you are on the right track with better cables. I'm using a wired connection, but I have seen problems with Pi WIFI when connected to a 3D printer. That printer probably throws out lots of noise from its high-powered motors.

You can buy clip-on ferrites - for example https://www.amazon.com/IEUYO-Ferrite-Signal-Suppressor-Diameter/dp/B07DPM44BV might be of some help. I use them on a lot of my ham radio and related equipment.

Steve

[Steven Hirsch]

Alas, I've already tried both a clip-on ferrite and a ring with several turns of the cable wrapped through it.  Made no difference.