Invalid Key/WiFi issues on RaspberryPi with USB dongle

GamerBene19 · April 23, 2025 at 11:17 PM

I've set up LibreELEC 12.0.2 on a RaspberryPi 2B (which has no onboard WiFi) with a USB WiFi dongle (Edimax EW-7811Un) for my grandparents.

The Pi connects to a Jellyfin server via OpenVPN, and when it works, it works great - however it sadly does not work often as the WiFi connection frequently breaks.

Similar to other threads I experience the same "Invalid Key" error.

I've written (and continuously expanded) this script to check and fix the WiFi and VPN connection which gets executed every 5m via cron:

Bash

#!/bin/bash

# Get the current time
timestamp() {
    date "+%Y-%m-%d %H:%M:%S"
}

# Path to the failure count file
FAIL_COUNT_FILE="/tmp/wifi_fail_count"
# Threshold when to reboot
MAX_FAIL_COUNT=6 # Since the script is run every 5m, this corresponds to 30m

# Read the current fail count (default to 0 if file doesn't exist)
if [ -f "$FAIL_COUNT_FILE" ]; then
    FAIL_COUNT=$(cat "$FAIL_COUNT_FILE")
else
    FAIL_COUNT=0
fi

# Debug output of connmanctl services
echo "$(timestamp) - Current connman services:"
connmanctl services

# Check if the Wi-Fi is connected using connman
if ! connmanctl services | grep -q "\*AR"; then
    echo "$(timestamp) - Wi-Fi is down. Attempting to reconnect..."

    # Perform a Wi-Fi scan
    echo "$(timestamp) - Scanning for available Wi-Fi networks..."
    connmanctl scan wifi
    sleep 5  # Allow time for scan to complete
    echo "$(timestamp) - Available Wi-Fi networks:"
    connmanctl services

    # Restart the network service
    systemctl restart connman

    # Wait a few seconds to allow reconnection
    sleep 10

    # Check again if connected
    if connmanctl services | grep -q "\*AR"; then
        echo "$(timestamp) - Wi-Fi reconnected successfully."
        echo 0 > "$FAIL_COUNT_FILE" # Reset counter
    else
        echo "$(timestamp) - Failed to reconnect Wi-Fi. Exiting."
	FAIL_COUNT=$((FAIL_COUNT + 1))
        echo "$FAIL_COUNT" > "$FAIL_COUNT_FILE"

        echo "$(timestamp) - Failure count: $FAIL_COUNT"
        if [ "$FAIL_COUNT" -ge "$MAX_FAIL_COUNT" ]; then
            echo "$(timestamp) - Reached $MAX_FAIL_COUNT failed attempts. Rebooting..."
            systemctl reboot
        fi
	exit 1
    fi
else
    echo "$(timestamp) - Wi-Fi is already connected."
    echo 0 > "$FAIL_COUNT_FILE" # Reset counter
fi

# Check if the VPN is working
echo "$(timestamp) - Checking VPN connection..."
VPN_TEST_URL="https://jellyfin.url.some.tld"
curl -L --silent --fail $VPN_TEST_URL > /dev/null
if [ $? -ne 0 ]; then
    echo "$(timestamp) - VPN connection is down. Restarting VPN..."

    # Reconnect VPN
    systemctl stop openvpn
    script_type=down /storage/.config/openvpn/update-nameservers.sh
    systemctl start openvpn

    # Wait for VPN to reconnect
    sleep 30

    # Recheck VPN connection
    curl -L --silent --fail $VPN_TEST_URL > /dev/null
    if [ $? -ne 0 ]; then
        echo "$(timestamp) - VPN reconnection failed."
    else
        echo "$(timestamp) - VPN reconnected successfully."
    fi
else
    echo "$(timestamp) - VPN is working correctly."
fi

Display More

The output of that looks something like this (in the most extreme cases)

Code

2025-04-09 12:50:00 - Current connman services:
*AR <TARGET-WIFI>        wifi_74da386e443b_..._managed_psk
    Some                 wifi_74da386e443b_..._managed_psk
    Other                wifi_74da386e443b_..._managed_psk
    Unrelated            wifi_74da386e443b_..._managed_psk
    WiFi                 wifi_74da386e443b_..._managed_psk
    Networks             wifi_74da386e443b_..._managed_psk
    From                 wifi_74da386e443b_..._managed_psk
    Random               wifi_74da386e443b_..._managed_psk
    Neighbours           wifi_74da386e443b_..._managed_psk
2025-04-09 12:50:00 - Wi-Fi is already connected.
2025-04-09 12:50:00 - Checking VPN connection...
2025-04-09 12:50:00 - VPN is working correctly.
2025-04-09 12:55:00 - Current connman services:
    WiFi                 wifi_74da386e443b_..._managed_psk
    From                 wifi_74da386e443b_..._managed_psk
    Random               wifi_74da386e443b_..._managed_psk
2025-04-09 12:55:00 - Wi-Fi is down. Attempting to reconnect...
2025-04-09 12:55:00 - Scanning for available Wi-Fi networks...
Scan completed for wifi
2025-04-09 12:55:07 - Available Wi-Fi networks:

2025-04-09 12:55:17 - Failed to reconnect Wi-Fi. Exiting.
2025-04-09 12:55:17 - Failure count: 1
2025-04-09 13:00:00 - Current connman services:

2025-04-09 13:00:00 - Wi-Fi is down. Attempting to reconnect...
2025-04-09 13:00:00 - Scanning for available Wi-Fi networks...
Scan completed for wifi
2025-04-09 13:00:07 - Available Wi-Fi networks:

2025-04-09 13:00:17 - Failed to reconnect Wi-Fi. Exiting.
2025-04-09 13:00:17 - Failure count: 2
2025-04-09 13:05:00 - Current connman services:

2025-04-09 13:05:00 - Wi-Fi is down. Attempting to reconnect...
2025-04-09 13:05:00 - Scanning for available Wi-Fi networks...
Scan completed for wifi
2025-04-09 13:05:07 - Available Wi-Fi networks:

2025-04-09 13:05:17 - Failed to reconnect Wi-Fi. Exiting.
2025-04-09 13:05:17 - Failure count: 3
2025-04-09 13:10:00 - Current connman services:

2025-04-09 13:10:00 - Wi-Fi is down. Attempting to reconnect...
2025-04-09 13:10:00 - Scanning for available Wi-Fi networks...
Scan completed for wifi
2025-04-09 13:10:07 - Available Wi-Fi networks:

2025-04-09 13:10:17 - Failed to reconnect Wi-Fi. Exiting.
2025-04-09 13:10:17 - Failure count: 4
2025-04-09 13:15:00 - Current connman services:

2025-04-09 13:15:00 - Wi-Fi is down. Attempting to reconnect...
2025-04-09 13:15:00 - Scanning for available Wi-Fi networks...
Scan completed for wifi
2025-04-09 13:15:07 - Available Wi-Fi networks:

2025-04-09 13:15:17 - Failed to reconnect Wi-Fi. Exiting.
2025-04-09 13:15:17 - Failure count: 5
2025-04-09 13:20:00 - Current connman services:

2025-04-09 13:20:00 - Wi-Fi is down. Attempting to reconnect...
2025-04-09 13:20:00 - Scanning for available Wi-Fi networks...
Scan completed for wifi
2025-04-09 13:20:07 - Available Wi-Fi networks:

2025-04-09 13:20:17 - Failed to reconnect Wi-Fi. Exiting.
2025-04-09 13:20:17 - Failure count: 6
2025-04-09 13:20:17 - Reached 6 failed attempts. Rebooting...
2025-04-09 13:25:00 - Current connman services:
*AR <TARGET-WIFI>        wifi_74da386e443b_..._managed_psk
    Some                 wifi_74da386e443b_..._managed_psk
    Other                wifi_74da386e443b_..._managed_psk
    Unrelated            wifi_74da386e443b_..._managed_psk
    WiFi                 wifi_74da386e443b_..._managed_psk
    Networks             wifi_74da386e443b_..._managed_psk
    From                 wifi_74da386e443b_..._managed_psk
    Random               wifi_74da386e443b_..._managed_psk
    Neighbours           wifi_74da386e443b_..._managed_psk
    Now                  wifi_74da386e443b_..._managed_psk
    More                 wifi_74da386e443b_..._managed_psk
2025-04-09 13:25:00 - Wi-Fi is already connected.

Display More

As you can see, connmanctl scan wifi and a subsequent systemctl restart connman do not always fix the issue, only rebooting does in this case.

I've also seen various mentions about this issue being related to poor reception (with the suggestion to use a USB dongle - which I already do) and that moving the WiFi client closer to the access point helped. While I don't want to dismiss that outright, I am rather skeptical that this is (purely) related to range/reception issues because I've seen all of below:

when the connection is present the dB value is "good" and it's fast enough to stream HD movies (~30 Mbit/s in my case)
sometimes suddenly no WiFi networks are found and 5-10m later everything is back to normal
sometimes WiFi networks from further away are found, but not the closer "target WiFI"
no other clients experience connection issues
mentions of it working in previous LE versions (where wpa_supplicant was used)
mentions of the same hardware working fine under RaspberryPi OS (and others)

I've found that in another thread iwctl was used to do the reconnect. Is there any (significant) difference between the iwctl and connmanctl?

Is there anything I can (still) do to improve the WiFi reliability except for buying something like this?

For now I am looking for a quickish solution to make my grandparents happy, but in the long run I am eager to help debug/improve the issue. Although I think it makes more sense to continue this thread instead.

Thanks in advance for all the help!

**chewitt** · April 24, 2025 at 5:40 AM

Start with updating to an LE13 nightly. There are newer versions of drivers and other wireless plumbing so the first step is to see if anything improves or changes.

GamerBene19 · April 24, 2025 at 10:54 AM

Quote from chewitt

Start with updating to an LE13 nightly. There are newer versions of drivers and other wireless plumbing so the first step is to see if anything improves or changes.

Can I update directly from within LibreELEC without reinstalling?
If so: How?
If not: Should I just use the latest nightly image, or are there ones that are considered "more stable" than the others? I'd like to avoid introducing new/other issues if possible.

**chewitt** · April 24, 2025 at 5:42 PM

As the saying goes: "past performance does not guarantee future performance" but I've been running LE13 nightlies for a year or more (albeit on an RPi5 not RPi2) without drama.

Download the relevant nightly file to /storage/.update and reboot. If you want to hedge your bets take a backup first as Kodi only handles upgrades not downgrades.

GamerBene19 · April 24, 2025 at 10:34 PM

Quote from chewitt

Download the relevant nightly file to /storage/.update

Is "the relevant nightly file" simply the latest img.gz from here? Also do I need to decompress it first?

I probably won't be able to try it out until Sunday, but I’ll let you know if anything changes (in regards to WiFi) once I do.

One thought/question: I am using the Estuary MOD V2 skin, do you happen to know if that breaks with LE 13?
I'll take a backup just to be sure, but it would be good to know beforehand if that skin will break.

While I have your attention: Is there a way to disable the connected TV from being controlled by the Pi via CEC? Currently the TV sometimes turns (and stays) on in the middle of the night, when the Pi reboots because of my script. I've looked into the settings of the CEC adapter addon, but perhaps I've not found the right knob yet.

Thanks for all the help so far!

**Da Flex** · April 24, 2025 at 11:43 PM

Quote from GamerBene19

Is "the relevant nightly file" simply the latest img.gz from here?

Yes, take the one with the latest date.

Quote from GamerBene19

Also do I need to decompress it first?

No. From SSH you can download and install (by reboot) without decompression:

Code

cd /storage/.update
wget https://test.libreelec.tv/13.0/RPi/RPi2/<COMPRESSED_IMAGE_NAME>
reboot

holland.pain · April 26, 2025 at 1:36 PM

Hi,

Re PI / TV see 15227-tv-turns-on-by-itself it may help

GamerBene19 · April 27, 2025 at 3:38 PM

Quote from GamerBene19

I probably won't be able to try it out until Sunday,

I just got back, here's a quick update:

Quote from holland.pain

Hi,
Re PI / TV see 15227-tv-turns-on-by-itself it may help

Thanks! Turns out, I missed the second part (Devices to power on during startup) when I initially looked through the menu. Setting it to none did do the trick - the TV no longer turns on by itself.

I also tried out the latest nightly build (LibreELEC-RPi2.arm-13.0-nightly-20250426-07a8ef5). The update itself was successful, but I had to downgrade again, because even after multiple reboots the Pi unfortunately did not establish a WiFi connection (and the associated menu in the settings was just empty).

I also did not have an Ethernet cable for SSH - or other means to open a terminal - at hand, so I wasn't able to diagnose the issue further. The only thing I saw was

Code

LibreELEC (community): nightly-20250426-07a8ef5
waiting on Network to come online...
[FAILED] Failed to start network-online.service.
[DEPEND] Dependency failed for openvpn.service.

during boot before Kodi started.

Note that both "the associated menu in the settings was just empty" and the above output during startup are usual symptoms under LE 12, when WiFi does not work. Usually it is fixed by a few reboots though - which did not seem to help with LE 13.

I have the same hardware (same Pi2 and WiFi Dongle) lying around somewhere. If I find them (and some time) I'll try to replicate the failing setup at (my) home for better debugging.

GamerBene19 · April 27, 2025 at 3:54 PM

Oh also the Enigma2 Client plugin does get disabled under LE 13 because it is incompatible. I suspect it's not actually incompatible, but just marked as such (or only marked to be compatible with LE 12). But that's a smaller secondary issue I noticed with LE 13, as the Pi mainly is used as a Jellyfin client and not for watching TV (that is done with the actual TV itself).