(My) Raspberry Pi Zero W has unacceptably low WiFi power

[pi_everalm]

Got a new in box Zero W as I was going to set up a VPN server on it to access home data when out and about.

Install went OK however when I first fired it up even though I have 3 Wi-Fi AP connections in the house (cable modem plus two Powerline repeaters) and on my laptop I see between 12 and 15 local AP's the Zero W will only see one, the cable modem and then only when it is within less than 10 feet of the cable box.

Thought it might be a user install issue so did a full clean format and reimage of the current (2017-04-10-raspbian-jesse) image to new SD card. Same problem, very poor range, low bandwidth

To confirm that the onboard WiFi was the issue I also plugged in a micro to regular USB connector and connected a Realtek USB Wi-Fi connector I have used with my RPi 2 before.

All results are where the Zero W sits within 2 feet of the hub, is a plain vanilla build that has only had apt-get update and apt-get upgrade run on it, has a clean 5V 2.5A power supply, the "virginmediaNNNNNNN" AP is the local hub name and wlan0 is the onboard Wi-Fi, wlan1 is the Realtek.

Run "iwconfig"

pi@raspberrypi:~ $ iwconfig
wlan0 IEEE 802.11bgn ESSID:"virginmediaNNNNNNN"
Mode:Managed Frequency:2.412 GHz Access Point: 84:1B:5E:B9:5C:7B
Bit Rate=19.5 Mb/s Tx-Power=31 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:on
Link Quality=40/70 Signal level=-70 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:2 Invalid misc:0 Missed beacon:0

lo no wireless extensions.

wlan1 IEEE 802.11bgn ESSID:"virginmediaNNNNNNN" Nickname:"<WIFI@REALTEK>"
Mode:Managed Frequency:2.412 GHz Access Point: 84:1B:5E:B9:5C:7B
Bit Rate:72.2 Mb/s Sensitivity:0/0
Retry:off RTS thr:off Fragment thr:off
Power Management:off
Link Quality=100/100 Signal level=100/100 Noise level=0/100
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

Reconnected the Realtek to one of the other Wi-Fi hubs to reduce possible contention

pi@raspberrypi:~ $ iwconfig
wlan0 IEEE 802.11bgn ESSID:"virginmedia2775378"
Mode:Managed Frequency:2.412 GHz Access Point: 84:1B:5E:B9:5C:7B
Bit Rate=28.8 Mb/s Tx-Power=31 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:on
Link Quality=43/70 Signal level=-67 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:8 Invalid misc:0 Missed beacon:0

lo no wireless extensions.

wlan1 IEEE 802.11bgn ESSID:"Home_hub1" Nickname:"<WIFI@REALTEK>"
Mode:Managed Frequency:2.427 GHz Access Point: BC:F2:AF:87:C4:45
Bit Rate:150 Mb/s Sensitivity:0/0
Retry:off RTS thr:off Fragment thr:off
Power Management:off
Link Quality=99/100 Signal level=60/100 Noise level=0/100
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

So, the problem is certainly the Zero W Wi-Fi connection.

Has anyone else seen this ridiculous level of connection issue with the Zero W or come across a possible fix..?

[linux_author]

no problem with my two pi0Ws... however, use raspi-config to check that your wifi freqs are set to your country's freqs - ran into this problem when i first started using an RPi3... in fact, even after setting the country code properly, i still had problems with no range, no connects or if connected, dropouts... turns out that i had my router set to channel 11 and even though the RPi3 should have been OK with it, it wasn't!

my solution was to reset my router's freq back to the middle range - ever since... no problem, even through concrete walls (although best connections are using a 'long-ducky' wifi dongle with my pi0s)

hth,

willie
on the sunny and warm Gulf of Mexico

[jdb]

If you're seeing -70dBm signal strength with the Zero W placed literally next to the AP, then this suggests that you may have a hardware defect on your Zero W.

Do you have another Zero W to compare with?

[bensimmo]

Can you turn power management on the Zero WiFi off, like the external one ?

[JMK8]

I get similar results with a Pi3B . Disabling the built-in wireless and plugging in an Edimax USB wireless adaptor gives far superior range and reliability.

(I'm not too worried because I will not be using wireless when the project is completed, but it is disappointing)

-JohnK

[W. H. Heydt]

I get similar results with a Pi3B . Disabling the built-in wireless and plugging in an Edimax USB wireless adaptor gives far superior range and reliability.

(I'm not too worried because I will not be using wireless when the project is completed, but it is disappointing)

-JohnK

Has the RTL driver issue been fixed, then? Or are you doing something manually to get the Edimax dongle to work?

[JMK8]

@W. H. Heydt

You got me worried with your post so I broke open my project box and physically checked how I had configured the two Pi’s in it. It seems that the grey matter is fading - I have used a Pi2BV1.1 and a Pi3BV1.2. The wireless dongle is plugged into the Pi2 and the wireless on the Pi3 is unused. In addition the wireless dongle is a “VILROS 802.11n” not an Edimax. I’m running 4.9.22-v7+ #987 SMP Fri Apr 14 23:23:05 BST 2017 armv7l GNU/Linux. Sorry for the confusion - my bad

Apart from all that I found that the VILROS dongle has a much greater range and reliability than the Pi3 wireless which is why I use the VILROS.

-JohnK.

[bensimmo]

The Vilros uses the same chipset rtl8188cus as the Edimax n150 Nano.
I have a couple of both. .
Both work out the box on the Pi.

(But going off topic now)

Though 4.9 kernel is a 'testing setup', so any problems should be reported on the github or 4.9 thread on here.
(If Raspian)
Also the Pi3 uses a different antenna setup to the Pi0W

[pi_everalm]

Thanks for the comments and suggestions.

Set localisation for Wi-Fi to UK then USA then back, no change in signal strength
The Wi-Fi channels are already set to low use channels, changed them to another couple of channels, retried the channel regionalisation, ditto no signal strength change

I have another Zero W order from a different vendor and will check if the issue is still there.
I have also ordered a micro USB pluggable Ethernet dongle that I will connect directly to the cable modem hub and see if there are any improvements or if throttling is occurring at the O/S level

If the issue persists across different batches then it is pretty safe to say that either the Wi-Fi chip/resonant antenna technology is fundamentally flawed, QA/QC is poor and inconsistent and letting only partially useable products onto the market or Raspberry are pushing a product that is simply not fit for purpose

Hopefully I just got one dodgy W and the second will work as advertised.

[jamesh]

If the issue persists across different batches then it is pretty safe to say that either the Wi-Fi chip/resonant antenna technology is fundamentally flawed, QA/QC is poor and inconsistent and letting only partially useable products onto the market or Raspberry are pushing a product that is simply not fit for purpose

Wow, second post and concern trolling already.

Best not to try and make assumptions from single statistical sample (given Pi0W have been made in the multiple 100k's). But just for you own confirmation, the antenna is not fundamentally flawed, the product is fit for purpose, and the QA/QC is fine.

The Pi range has an incredibly low failure rate, much less than industry average. However, occasionally you get something through the system that fails between testing on the production line, and getting to a customer. Might have happened to you.

[mfa298]

The Wi-Fi channels are already set to low use channels, changed them to another couple of channels, retried the channel regionalisation, ditto no signal strength change

Just because a channel appears to be low use doesn't always mean it's a good choice. The wireless channels overlap other channels so even if 10 appeared to be low use if channel 11 was really busy then you might run into problems. Generally channels 1,6,11 are the best options as they don't overlap with each other so you may do best to choose whichever of those is lower use and take into account the usage on neighbouring channels.

[Pithagoros]

I haven't troubled myself to work out why, but my Pi0W WiFi and Bluetooth performance (meaning useful range) is not as good as my iPhone, but interestingly far better than any Pi3 version I've tried.

My desk where I operate these things is about 10 metres and a wall and door away from the access point.

[pi_everalm]

"Concern trolling".... hardly.

"the action or practice of disingenuously expressing concern about an issue in order to undermine or derail genuine discussion"

I have a product that I bought based on it's pedigree. and have used the Pi range for the last 3 years in its various incarnations. As such, I purchased, in a range that TO DATE has not been a problem for me, a piece that has demonstrated a fundamental problem.

I articulate and show the issue, provide the information, demonstrate rigor and thoroughness in the tests, show the results and ask the community at large about the issue.

I finish with a view of possible root causes along with a statement that I am waiting to see if the issue is reproducible with a new and separately sourced replacement before making any further judgement, specifically, "Hopefully I just got one dodgy W and the second will work as advertised."

Suggest you read the post and context before making such comments particularly when acting as a moderator.

[linux_author]

pi0w.jpg (46.63 KiB) Viewed 8650 times

not sure if this is the result of someone attempting a hardware hack, but the poster swears his pi0W came out of the box like this...

QC issue or not?

original post:

viewtopic.php?p=1150195#p1150195

fortunately the two pi0Ws i've received work fine - truly a remarkable achievement and great little SBC

willie
on the sunny and warm Gulf of Mexico

[jamesh]

"Concern trolling".... hardly.

"the action or practice of disingenuously expressing concern about an issue in order to undermine or derail genuine discussion"

I have a product that I bought based on it's pedigree. and have used the Pi range for the last 3 years in its various incarnations. As such, I purchased, in a range that TO DATE has not been a problem for me, a piece that has demonstrated a fundamental problem.

I articulate and show the issue, provide the information, demonstrate rigor and thoroughness in the tests, show the results and ask the community at large about the issue.

I finish with a view of possible root causes along with a statement that I am waiting to see if the issue is reproducible with a new and separately sourced replacement before making any further judgement, specifically, "Hopefully I just got one dodgy W and the second will work as advertised."

Suggest you read the post and context before making such comments particularly when acting as a moderator.

Nope, concern troll line is this one "it is pretty safe to say that either the Wi-Fi chip/resonant antenna technology is fundamentally flawed, QA/QC is poor and inconsistent and letting only partially useable products onto the market or Raspberry are pushing a product that is simply not fit for purpose". You have stated the problem can be one of three things, non of which show the product in a good light, and none of which are actually true. So, yes, I did read you post, and I still think it's concern trolling since you have missed out a number of other issues that could easily be the problem, and which do not show the product in a bad light. You have, in effect diagnosed the problem and made up your own mind on what the root cause may be, without the diagnosis being confirmed, or even being likely.

Even your last post states there is a fundamental problem. Fundamental? Really? So fundamental that of the 100k's of other users of exactly the same device, you seem to be one of the few people who has seen an issue? Surely such a fundamental problem would be somewhat more frequently reported?

So, given that the problem is clearly not a fundamental one, it would be interesting to find out actually what it is. My guess would be a defect that made it through production test, or occurred after testing. If the new device shows the same symptoms, then that would indicate an environmental (or perhaps setup) problem, since Zero's Wireless range has been reported at over 90m in the open air, and it seems unlikely you would receive two faulty devices.

[jamesh]

pi0w.jpg

not sure if this is the result of someone attempting a hardware hack, but the poster swears his pi0W came out of the box like this...

QC issue or not?

original post:

viewtopic.php?p=1150195#p1150195

fortunately the two pi0Ws i've received work fine - truly a remarkable achievement and great little SBC

willie
on the sunny and warm Gulf of Mexico

That would not have passed production test - both the wireless chip test and the optical test would have found that problem. Looking at it closely you can also see damage on the side of the Wifi chip - clearly it has suffered impact damage at some point.

[linux_author]

that would have been my guess... i wonder if someone stepped on it before/during shipping?

a couple months ago i received an SSD1306 OLED... opened up the tiny ziplock, and ...

pieces of glass and glass dust fell out!



feel sorry for the OP though...

willie
on the Gulf of Mexico

[pi_everalm]

Well, we have a good news/bad news situation......

Second PiZero W arrived and yay, Wi-Fi is acceptably useable, problem is...the camera interface is broken out of the bag (see attached image).......

Distinctly frustrating since the intent is to bodge together 2 separate POC's,

One with a GSM/GPRS shield as a bare bones hand held PiPhone/webcam componentised sufficiently that it can also be broken down and reused as a wearable phone, repurposing an old ScottEvest as the carrier

http://sixfab.com/product/gsmgprs-shield/
https://www.scottevest.com/

The second bodge will be PiZero W, smart power management "LiFePO4wered" UPS and GPS/3G shield. Wireless AP, tracker, webcam, sensor platform, phone etc...whatever your fertile little mind can devise

https://www.tindie.com/products/xorbit/lifepo4weredpi3/
http://sixfab.com/product/3g-4glte-base-shield/

Ho-hum, both zero's being sent back for replacement, hopefully 3 and 4 the times the charm

[jamesh]

Those camera connectors are quite fragile, but there's not really another option - they need to be very cheap, and they need to be very small. Finding cheap and small AND strong isn't easy!