port: /dev/serial/by-id/usb-1a86_USB_Serial-if00-port0



====== 2.5 Gigbait ======


https://thepihut.com/blogs/raspberry-pi-tutorials/how-to-install-the-realtek-rtl8125-2-5g-ethernet-driver-on-ubuntu?srsltid=AfmBOooGJb8Sc3k2x5gR3bfxkXeYAa9Tace47M7JcipCYUn8ZHb12UhV

====== POE PI4 ======

https://botland.de/gpio-erweiterungen-und-hats-fur-raspberry-pi-4b/19593-power-over-ethernet-hat-d-poe-stromversorgung-und-8023af-netzwerk-fur-raspberry-pi-3b-4b-waveshare-19532-5904422364632.html

====== boot usb ======

https://raspberrystreet.com/learn/how-to-boot-raspberrypi-from-usb-ssd

====== buy Raspberry PI ======

von Uwe

https://buyzero.de/blogs/news/raspberry-pi-reservation-tool-auf-picockpit

====== killed processes check ======

 dmesg -T | egrep -i 'killed process'

 oom

====== Water automated ======

https://community.home-assistant.io/t/automatic-motorized-water-shut-off-valves/173501/48

====== control-usb-powered-devices ======


https://funprojects.blog/2021/04/26/control-usb-powered-devices/

====== backup options ======


  dd bs=4M if=/dev/sdd of=/mnt/hdd/backup/raspberry-pi/pi4-iptv-`date +%d%m%y`.img
  dd bs=4M if=/dev/sdd of=/mnt/hdd/backup/raspberry-pi/pi4-has-`date +%d%m%y`.img

or 

  dd bs=4M if=/dev/sdb | gzip > /mnt/hdd/backup/raspberry-pi/image`date +%d%m%y`.gz


====== Headline ======

  cat /sys/class/thermal/thermal_zone0/temp

  echo ">> CPU Freq:" $(($(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq)/1000))MHz


  https://www.raspberrypi.org/forums/viewtopic.php?t=252115