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by ncguk
Wed Jul 10, 2019 6:44 pm
Forum: Troubleshooting
Topic: Network fails after rebooting but fine after shutting down
Replies: 74
Views: 3300

Re: Network fails after rebooting but fine after shutting down

I'm having a similar problem here. I have a Samsung Evo 32GB microSD card with Buster on it (with a static eth0 IP address set outside of the DHCP range in /etc/network/interfaces) that has been working just fine at boot and between reboots on a Pi 4 2GB model. I've just taken the card, put it into ...
by ncguk
Fri May 17, 2019 9:56 pm
Forum: Advanced users
Topic: Moving Linux kernel to 4.19
Replies: 270
Views: 88049

Re: Moving Linux kernel to 4.19

Thank you guys for suggesting Pi-Hole as the problem, in my query log the following site was blocked in A (ipv4) and AAAA (ipv6) too: codeload.github.com after whitelisted from query log the problem solved (at least in my case). Thank you again, and regards I can also confirm that whitelisting code...
by ncguk
Sat May 11, 2019 10:09 pm
Forum: Advanced users
Topic: Moving Linux kernel to 4.19
Replies: 270
Views: 88049

Re: Moving Linux kernel to 4.19

Problem solved. Something in my Pi-hole blocklists was causing the problem. Temporarily disabling them caused rpi-update to start working again.
by ncguk
Wed May 08, 2019 10:09 am
Forum: Advanced users
Topic: Moving Linux kernel to 4.19
Replies: 270
Views: 88049

Re: Moving Linux kernel to 4.19

Apologies for the delay in replying. As of this post I'm still receiving the "Invalid git hash specified" message. If no-one else is having the problem, I can only assume something's wonky at my end.
by ncguk
Mon May 06, 2019 12:37 pm
Forum: Advanced users
Topic: Moving Linux kernel to 4.19
Replies: 270
Views: 88049

Re: Moving Linux kernel to 4.19

As of 1.35pm, 6 May 2019, "sudo rpi-update" gives the error "Invalid git hash specified". Tested on RPi Zero W and RPi3 running stock Raspbian.
by ncguk
Tue Feb 19, 2019 8:26 pm
Forum: Advanced users
Topic: Moving Linux kernel to 4.19
Replies: 270
Views: 88049

Re: Moving Linux kernel to 4.19

Have upgraded to 4.19 kernel on a Pi Zero W running Raspbian and a Raspberry Pi 2 running Arch. Both failed to start on first reboot, but after pulling the plug on them and cold booting them, both came up fine. Just posting that in case anyone runs into the same issue and thinks their install is kna...
by ncguk
Mon Feb 26, 2018 6:26 pm
Forum: Raspbian
Topic: Help building a 64 bit Raspbian/Debian image
Replies: 0
Views: 394

Help building a 64 bit Raspbian/Debian image

What I would like to do is put together my own 64 bit Raspbian/Debian disk image, using the RPi kernel built for 64 bit (so that it will still use the Raspbian dt overlays) and with a matching 64 bit Debian minimal install. The reason for wanting to do this is so I can still access the pps-gpio.dtbo...
by ncguk
Mon Aug 21, 2017 1:17 pm
Forum: Troubleshooting
Topic: Raspbian Stretch: Wifi not starting on boot
Replies: 93
Views: 128918

Re: Raspbian Stretch: Wifi not starting on boot

ShiftPlusOne wrote:
Mon Aug 21, 2017 1:07 pm
The default wpa_supplicant.conf, looks like this:

Code: Select all

country=GB
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
I would recommend having that header before the network blocks.

Will do. That one was definitely user oversight.
by ncguk
Mon Aug 21, 2017 12:24 pm
Forum: Troubleshooting
Topic: Raspbian Stretch: Wifi not starting on boot
Replies: 93
Views: 128918

Re: Raspbian Stretch: Wifi not starting on boot

Okay. Solved it. Running sudo journalctl on a completely fresh install of Raspbian Stretch Lite on a Pi Zero W gave me the information I needed: Aug 16 01:22:47 raspberrypi dhcpcd-run-hooks[261]: wlan0: ctrl_interface not defined in /etc/wpa_supplicant/wpa_supplicant.conf Aug 16 01:22:47 raspberrypi...
by ncguk
Fri Aug 18, 2017 7:08 pm
Forum: Troubleshooting
Topic: Raspbian Stretch: Wifi not starting on boot
Replies: 93
Views: 128918

Re: Raspbian Stretch: Wifi not starting on boot

The following is from a Pi Zero W with a clean install of Raspbian Lite Stretch: apt-cache policy dhcpcd5: dhcpcd5: Installed: 1:6.10.1-1+rpi3 Candidate: 1:6.10.1-1+rpi3 Version table: *** 1:6.10.1-1+rpi3 500 500 http://archive.raspberrypi.org/debian stretch/main armhf Packages 100 /var/lib/dpkg/sta...
by ncguk
Fri Aug 18, 2017 9:59 am
Forum: Troubleshooting
Topic: Raspberry PI B+ WiFi no longer working after upgrade to raspbian stretch.
Replies: 2
Views: 939

Re: Raspberry PI B+ WiFi no longer working after upgrade to raspbian stretch.

Just to update this – I retested on a new Raspbian Lite Stretch install and the 'sudo systemctl enable wpa_supplicant.service' step is not necessary. Do everything else and reboot and it should work.
by ncguk
Fri Aug 18, 2017 9:44 am
Forum: Troubleshooting
Topic: Raspbian Stretch: Wifi not starting on boot
Replies: 93
Views: 128918

Re: Raspbian Stretch: Wifi not starting on boot

I just double-checked my fix with a brand new install of Raspbian Lite Stretch, and it works with wlan0 as the interface name. In fact, you don't even need to perform the 'sudo systemctl enable wpa_supplicant.service' step. I've not seen any evidence of the new 'predictable' interface names, but it ...
by ncguk
Thu Aug 17, 2017 11:02 pm
Forum: Troubleshooting
Topic: Raspbian Stretch: Wifi not starting on boot
Replies: 93
Views: 128918

Re: Raspbian Stretch: Wifi not starting on boot

I've been fighting this all evening. My solution on a fresh Raspbian Lite install: Make sure your wpa_supplicant.conf is in place then do sudo nano /etc/network/interfaces and add allow-hotplug wlan0 iface wlan0 inet manual wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf to the end of the file. The...
by ncguk
Thu Aug 17, 2017 8:09 pm
Forum: Troubleshooting
Topic: Raspbian Stretch: issue with PPS accuracy of NTP.
Replies: 9
Views: 4768

Re: Raspbian Stretch: issue with PPS accuracy of NTP.

IIRC, stock Debian NTP doesn't have PPS support enabled so you'll have to recompile NTP with --enable-ATOM in the ./configure line, making sure the file timepps.h is in /usr/include. That should improve matters.
by ncguk
Tue Apr 19, 2016 6:44 pm
Forum: Linux Kernel
Topic: Excessive number of "bioset" kernel processes in 4.4 kernel
Replies: 3
Views: 11206

Excessive number of "bioset" kernel processes in 4.4 kernel

On an RPi2 and an RPi B+ running a vanilla kernel straight from rpi-update, I have 25 kernel processes named bioset showing in top output. I'm ssh'ing into both Pis. I didn't see this with the 4.1 kernel. Before I make a bug report, is anyone else seeing this, and is it expected behaviour with 4.4?
by ncguk
Thu Dec 10, 2015 11:48 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Disabling UART FIFO
Replies: 2
Views: 570

Re: Disabling UART FIFO

That'll teach me to write on auto-pilot. I mean jitter, not latency.
by ncguk
Thu Dec 10, 2015 11:26 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Disabling UART FIFO
Replies: 2
Views: 570

Disabling UART FIFO

Is there a way of disabling the UART FIFO on the Pi (to lower latency)? The standard Linux way is to use Setserial to trick the UART into thinking it's an 8250 (which doesn't have a FIFO), but this doesn't work on the Pi and Setserial will always report "uart: undefined".
by ncguk
Wed Jan 14, 2015 7:50 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Wiring up and reading 1Hz square wave output from RTC
Replies: 5
Views: 2038

Re: Wiring up and reading 1Hz square wave output from RTC

Never mind – the cause of the problem was operator error. Though I believed I had enable the square wave output in the DS3231 I in fact hadn't. Using this library: https://github.com/radekw/Arduino/tree/master/Libraries/Chronodot And this Arduino sketch: #include <Wire.h> #include <Chronodot.h> // c...
by ncguk
Wed Jan 14, 2015 2:24 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Wiring up and reading 1Hz square wave output from RTC
Replies: 5
Views: 2038

Re: Wiring up and reading 1Hz square wave output from RTC

Do you get any PPS messages in the kernel message log (dmesg command)? dmesg | grep pps shows: [ 0.000000] Kernel command line: dma.dmachans=0x7f35 bcm2708_fb.fbwidth=656 bcm2708_fb.fbheight=416 bcm2708.boardrev=0x12 bcm2708.serial=0xcd587ca6 smsc95xx.macaddr=B8:27:EB:58:7C:A6 bcm2708_fb.fbswap=1 b...
by ncguk
Wed Jan 14, 2015 1:43 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Wiring up and reading 1Hz square wave output from RTC
Replies: 5
Views: 2038

Re: Wiring up and reading 1Hz square wave output from RTC

https://github.com/raspberrypi/linux/pull/717 Have you missed adding bcm2708.pps_gpio_enable=1 to cmdline? That syntax was changed by the developers at the last minute to what I quote above, a way which has worked successfully for me with GPS 1PPS output, so it's nothing that simple (if only it wer...
by ncguk
Wed Jan 14, 2015 12:08 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Wiring up and reading 1Hz square wave output from RTC
Replies: 5
Views: 2038

Wiring up and reading 1Hz square wave output from RTC

I've scoured Google for a solution to this to no avail. I'm trying to hook up the 1Hz square wave output of a DS3231 RTC breakout board to GPIO18 (pin 12) of the Pi. As per information on the web I've turned on the wave output (theoretically, using an Arduino sketch) and added a resistor between SQW...
by ncguk
Fri Dec 05, 2014 4:50 pm
Forum: Networking and servers
Topic: Reducing Pi network latency and jitter
Replies: 0
Views: 1469

Reducing Pi network latency and jitter

Hi all, I'm using a Pi as a stratum-1 NTP server and am looking for ways to reduce network latency and jitter. I'm aware the ethernet port is on the USB bus so will never be quite as good as dedicated ethernet port, but for a relatively low traffic service such as NTP the Pi does very well. Things I...
by ncguk
Sun Nov 16, 2014 10:36 pm
Forum: Linux Kernel
Topic: Is there a way to turn off dynamic ticks in userland?
Replies: 3
Views: 2793

Re: Is there a way to turn off dynamic ticks in userland?

Ah, okay. I've tried that using the stock kernel with no appreciable difference (anecdotally, based on repeated viewings of ntpq -p over a period of hours rather than with any rigorous testing), whereas compiling a kernel with Timer tick handling and Old idle dynticks config disabled and the resulti...
by ncguk
Sun Nov 16, 2014 8:40 pm
Forum: Linux Kernel
Topic: Is there a way to turn off dynamic ticks in userland?
Replies: 3
Views: 2793

Is there a way to turn off dynamic ticks in userland?

The recent changes to the Raspbian kernel that enable the easy use of PPS on the Pi are most welcome for users trying to maintain a stratum 1 NTP server, but there's a problem remaining: dynamic ticks. From what I've read (and experienced from building a custom kernel) a tickless kernel is hugely be...
by ncguk
Wed Aug 06, 2014 12:05 pm
Forum: Python
Topic: Python and timed loops
Replies: 4
Views: 1459

Re: Python and timed loops

If you want mytime() to flash the colon, then you'll need to move "colon = True" outside of the mytime function, and have "global colon" as the first line of mytime (to indicate that you're accessing the global colon variable, and not a new local colon variable which is only valid within each call ...

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