Saturday, July 11, 2020

When a Windows 10 update breaks the dual boot

Execute the following commands using a LiveCD:

sudo mount /dev/sdXY /mnt
sudo mount /dev/sdXX /mnt/boot/efi
for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; done
sudo chroot /mnt
grub-install /dev/sdX
update-grub

Note that X and Y are only used as an example. E.g. it can be that the EFI system partition is on a completely different disk (hard drive) than the Linux system, which needs to be repaired.

Thursday, August 30, 2018

Turning off LEDs on Raspberry Pi 3 Model B

I found the solution here: https://raspberrypi.stackexchange.com/questions/70593/turning-off-leds-on-raspberry-pi-3 and it works for Raspberry Pi 3 Model B too. The following lines should be added to /etc/rc.local:

sudo sh -c 'echo none > /sys/class/leds/led0/trigger'
sudo sh -c 'echo none > /sys/class/leds/led1/trigger'
sudo sh -c 'echo 0 > /sys/class/leds/led0/brightness'
sudo sh -c 'echo 0 > /sys/class/leds/led1/brightness'


The other method with /boot/config.txt didn't work for me.

Friday, December 8, 2017

Multiple WiFi Networks with Raspberry Pi

All of this information (and more) is available on https://www.raspberrypi.org/documentation/configuration/wireless/wireless-cli.md.

All the WiFi network credentials should be listed in this file: /etc/wpa_supplicant/wpa_supplicant.conf. It should look like this:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=DE

network={
    ssid="ssid1"
    psk="plaintextpassword1"
    key_mgmt=WPA-PSK
}

network={
    ssid="ssid2"
    psk="plaintextpassword2"
    key_mgmt=WPA-PSK
}


Some additional useful commands:
  • List all available WiFi networks: iwlist wlan0 scan
  • Generate encrypted password: wpa_passphrase
  • Reconfigure the interface: wpa_cli -i wlan0 reconfigure
  • Verify if the connection was successful: ifconfig wlan0
For hidden networks add the scan_ssid=1 option, for priorization use the priority=1.

Friday, May 26, 2017

A Reschenpass Körül

Az Ortler Bike Marathon pályáját jártuk be. Kicsit sok benne az aszfaltos rész, több helyen viszont egyáltalán nem tekerhető, főleg fölfelé. Lefelé csak egyszer kellett leszállni. :)

A Haidersee St. Valentin felől
Kempinghangulat
Schloss Churburg
Régi templomtorony a Reschensee-ben, már a célegyenesben...
Kilátás a kempingből
A még havas Ortler
St. Valentin utcáin

Monday, May 1, 2017

Zuckerhut

Égig érő fák
Ellenfényben
Lendületben

Wednesday, December 28, 2016

Sony HDR-AS200V - "MAX"

I'm using the timelapse function very often with this particular camera and today I ran into one of the limitations of this feature. I just started a new timelapse and a weird "MAX" error message started to blink on the screen... Strangely, there is an upper limit, how many photos you can take with the camera: "The maximum number of files that can be recorded has been reached". The limit is 40.000 photos, which can be easily exceeded with a large enough SD card. The only workaround I found is removing the contents of the AVF_INFO directory or formatting the SD card.

Sunday, November 6, 2016

Riedlingeni Séta

Őszi hangulat
Az üres főutca, szombat délután
Dőlésszögek
Lila ablakszárnyak
A Duna Riedlingennél