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by emw
Wed Sep 26, 2018 7:50 pm
Forum: Advanced users
Topic: simultaneous usb gadget and host
Replies: 4
Views: 832

simultaneous usb gadget and host

I want to use a Raspberry Pi Zero W to capture (and manipulate) data between a computer and a usb printer. I was thinking I could set up two usb ports - one a host USB port, the other a device (gadget) port. The gadget port would have to be configured to look like the printer. Unfortunately the pi o...
by emw
Thu Nov 30, 2017 8:43 pm
Forum: Troubleshooting
Topic: usb wifi adpater fails after down-up
Replies: 6
Views: 765

Re: usb wifi adpater fails after down-up with predictable network names

OK, my mind must be play tricks on me. This does not seem to me happening if I have predictable network names turned off (i'm sure I saw it both ways be can't get it to happen again). I have run over a 100 cycle of "ip link set wl.... down/ifup follow by a delay and ifconfig for the usb wifi adpater...
by emw
Thu Nov 30, 2017 5:44 pm
Forum: Troubleshooting
Topic: predictable interface names failing in Stretch
Replies: 32
Views: 13979

Re: predictable interface names failing in Stretch

My experience with post 2017-09-07 release has been different. Things work on nicely with both predictable on or off if you do a power on reset (onboard = wlan0) however if you do a soft reset (sudo reboot) the interfaces sometimes come up reversed (onboard = wlan1). This happens even with predictab...
by emw
Thu Nov 30, 2017 4:57 pm
Forum: Troubleshooting
Topic: USB wifi problem
Replies: 2
Views: 861

Re: USB wifi problem

Did you ever figure this out?
by emw
Thu Nov 30, 2017 4:33 pm
Forum: Troubleshooting
Topic: usb wifi adpater fails after down-up
Replies: 6
Views: 765

Re: usb wifi adpater fails after down-up

Definitely not a power issue. tested with 4A 5.4V Power supply and everything is the same.
by emw
Wed Nov 29, 2017 10:57 pm
Forum: Troubleshooting
Topic: usb wifi adpater fails after down-up
Replies: 6
Views: 765

Re: Only one wifi device comes back up

So it look like the result of down'ing the usb wifi adapter is a slightly random effect. I have had a few good passes with not stack traces in the systlog... others where there is a stack trace in the syslog, but the system work afterwords. It seems to work better on a virgin SD card (no mods other ...
by emw
Wed Nov 29, 2017 8:57 pm
Forum: Troubleshooting
Topic: usb wifi adpater fails after down-up
Replies: 6
Views: 765

Re: Only one wifi device comes back up

Tried the sudo rpi-update && sudo reboot and it didn't help. Also tried it with a fresh clean install, still no good.
by emw
Tue Nov 28, 2017 7:57 pm
Forum: Troubleshooting
Topic: usb wifi adpater fails after down-up
Replies: 6
Views: 765

Re: Only one wifi device comes back up

I can't get wlan0 to fail anymore. not sure why. I also found the folllowing in the syslog... which shows the crash but does not explain what is causing it. I am going to try rebuild the file system to see if that helps. Nov 28 19:49:15 PI-B827EBEED6DF dhcpcd[2046]: wlx74da386d1ecd: carrier lost Nov...
by emw
Tue Nov 28, 2017 7:24 pm
Forum: Troubleshooting
Topic: usb wifi adpater fails after down-up
Replies: 6
Views: 765

usb wifi adpater fails after down-up

I have raspbian-lite Pi 3 that I am using with a usb wifi adapter . I only intend to have one device up at a time. I use "sudo ip link set xxxx down" and "sudo ip link set xxxx up" to bring them up and down. When I initially boot the system both wifi devices will work... connecting to the router. Af...
by emw
Tue Nov 28, 2017 6:14 pm
Forum: Beginners
Topic: how to automatically disable wifi when wired connection is present (stretch).
Replies: 4
Views: 1964

Re: how to automatically disable wifi when wired connection is present (stretch).

ifplugd was not installed by default for stretch. I also thought it relied on ifup and ifdown which don't work on stretch. It looks like you can replace the ifup and ifdown in the script. So to it looks like I can still install and use use ifplugd or netplug. It also looks like I could do it with dh...
by emw
Mon Nov 27, 2017 6:33 pm
Forum: Beginners
Topic: how to automatically disable wifi when wired connection is present (stretch).
Replies: 4
Views: 1964

Re: how to automatically disable wifi when wired connection is present (stretch).

But how do you get the script to trigger when a cable is plugged in / unplugged (or actually when a connection is made / lost) ?
by emw
Fri Nov 24, 2017 6:54 pm
Forum: Beginners
Topic: how to automatically disable wifi when wired connection is present (stretch).
Replies: 4
Views: 1964

how to automatically disable wifi when wired connection is present (stretch).

How do you automatically disable wifi when a wired connection is present (stretch)? I know there are a lot of articles about this, but they don't seem to work for stretch.
by emw
Wed Nov 22, 2017 7:03 pm
Forum: Beginners
Topic: Connecting to wifi router after changing wpa_supplicant.config without reboot (stretch)
Replies: 11
Views: 20556

Connecting to wifi router after changing wpa_supplicant.config without reboot (stretch)

How do you get the raspberry pi to connect to the wifi router after setting the ssid/password without rebooting. In older versions I just used 'sudo ifdown wlan0; sudo ifup wlan0' but ifupdown is not supported on stretch. I have tried each of the following, none of which have work: sudo systemctl re...
by emw
Fri Nov 17, 2017 9:26 pm
Forum: Advanced users
Topic: Automaticaly Disable wlan0 on Pi 3 when a USB Wifi adapter is present
Replies: 6
Views: 2230

Re: Automaticaly Disable wlan0 on Pi 3 when a USB Wifi adapter is present

ok, looks like I got it working by enabling predictable names and using the following: /etc/dhcpcd.exit-hook case "$reason" in BOUND|RENEW|REBIND|REBOOT|TIMEOUT) if [ "0" != "`ip link show |grep -c wlx`" ]; then if [ "0" != "`ip link show |grep -c 'wlan0.*UP'`" ]; then ip link set wlan0 down fi fi ;...
by emw
Fri Nov 17, 2017 1:28 am
Forum: Advanced users
Topic: Automaticaly Disable wlan0 on Pi 3 when a USB Wifi adapter is present
Replies: 6
Views: 2230

Re: Automaticaly Disable wlan0 on Pi 3 when a USB Wifi adapter is present

Thanks the unique names helps DougieLawson, but even worse... this ifup/ifdown stuff does not work on Stretch.
by emw
Wed Nov 15, 2017 9:43 pm
Forum: Advanced users
Topic: Automaticaly Disable wlan0 on Pi 3 when a USB Wifi adapter is present
Replies: 6
Views: 2230

Re: Automaticaly Disable wlan0 on Pi 3 when a USB Wifi adapter is present

argh..... on "sudo reboot" the usb wifi is wlan0 and the onboard is wlan1....
by emw
Tue Nov 14, 2017 9:02 pm
Forum: Advanced users
Topic: Automaticaly Disable wlan0 on Pi 3 when a USB Wifi adapter is present
Replies: 6
Views: 2230

Re: Automaticaly Disable wlan0 on Pi 3 when a USB Wifi adapter is present

ok, I have been able to get this kind of working using if-down.d and if-up.d. This works reliably except when the USB wifi adapter is hot plugged which sometimes works. again any advice would be appreciated. /etc/network/if-down.d/wlan1: #!/bin/sh if [ "$IFACE" = "wlan1" ]; then /sbin/ifup wlan0 /sb...
by emw
Wed Nov 08, 2017 10:39 pm
Forum: Advanced users
Topic: Automaticaly Disable wlan0 on Pi 3 when a USB Wifi adapter is present
Replies: 6
Views: 2230

Automaticaly Disable wlan0 on Pi 3 when a USB Wifi adapter is present

I would like to configure my RPi3 to automatically down/disable the on board wifi (wlan0), when a USB Wifi adapter is present. I have found plenty of info on how to disable the on board wifi, but have not been able to find any information on how to do this only when a USB Wifi adapter is present. Ca...
by emw
Tue May 17, 2016 11:08 am
Forum: Advanced users
Topic: Pi3 conflict between Bluetooth WiFi
Replies: 7
Views: 8909

Re: Pi3 conflict between Bluetooth WiFi

There seem to be some improvement to the wifi operation (at the expense of the bluetooth) in last weeks release of raspbian. You may want to try this for your application.
by emw
Thu Apr 28, 2016 6:39 pm
Forum: General discussion
Topic: Code Obtain RSSI from raspberry3
Replies: 6
Views: 8843

Re: Code Obtain RSSI from raspberry3

Here is some sample code that does an lescan with rssi: https://github.com/glock45/intel-edison ... ter/scan.c
by emw
Thu Apr 28, 2016 10:13 am
Forum: Advanced users
Topic: Pi3 conflict between Bluetooth WiFi
Replies: 7
Views: 8909

Re: Pi3 conflict between Bluetooth WiFi

I have been able to isolate this down a simple low level test cases test case to show the conflict if this helps any When I attempt to make a connection to a a bluetooth LE device and the connection does not establish (or the device does not exist), wifi is disable (or has >99% packet loss) while th...
by emw
Thu Apr 28, 2016 10:10 am
Forum: Troubleshooting
Topic: rpi3 wireshark Protocol 0x886c
Replies: 3
Views: 3331

rpi3 wireshark Protocol 0x886c

I have been doing some wireshark traces on the RPi3 (with jessie) and I am getting a lot of Protocol = 0x886c (unknown) packets. Does anyone know what these packets are and what I need to do to turn them off. Wireshark indicates these packets are coming from another mac address (mine with the LG bit...
by emw
Wed Apr 27, 2016 1:50 pm
Forum: General discussion
Topic: Bluetooth Connectivity Issues with RPi 3
Replies: 4
Views: 6987

Re: Bluetooth Connectivity Issues with RPi 3

OK, the "Device or resource busy (16)" error only happens when I am actively sending data over wifi. Also I noticed that unless LE_Scan_Interval / LE_Scan_Window are set to 0x0004 (or lower?) I get very high wifi packet loss (30%+ depending on settings). Since I have multiple RPi 3 devices talking t...
by emw
Tue Apr 26, 2016 2:34 pm
Forum: General discussion
Topic: Raspberry Pi 3 Antenna Part Number
Replies: 4
Views: 906

Re: Raspberry Pi 3 Antenna Part Number

??? Not sure what the purpose of the link is.
by emw
Tue Apr 26, 2016 12:53 pm
Forum: General discussion
Topic: Raspberry Pi 3 Antenna Part Number
Replies: 4
Views: 906

Raspberry Pi 3 Antenna Part Number

Does anyone know the manufacturer / part number of the chip antenna used on the Raspberry Pi 3?

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