====== Raspberry Pi ======

===== Models =====

There are several form factors:
  * A
  * B
  * zero
  * compute module

Usually you want the "B" version which is the "standard" nowadays.

==== v4 ====
The first iterations of the Raspberry Pi v4 had some problems with USB voltage regulation.

There are three models of the Raspberry Pi 4, different in RAM size: 2GB, 4GB, 8GB.

The 8GB version is thought for memory intensive tasks, usually the 4GB version is enough for most applications though.

===== Linux distributions =====

==== general purpose ====
  * [[https://dietpi.com/|DietPi]] – lightweight and easy to install Debian based OS.
  * [[https://www.raspbian.org/|Raspbian]] – "standard" or "reference" OS for Raspberry Pi, it's supported by the Raspberry Pi Foundation
  * [[https://archlinuxarm.org/|Arch Linux ARM]] – rolling release distribution for advanced users.

==== specialised ====
  * [[https://libreelec.tv/|LibreElec]] – Turn your Raspi in a home entertainment system
  * [[https://retropie.org.uk/|RetroPie]] – uses Raspbian as a base, along with [[https://emulationstation.org/|EmulationStation]] and RetroArch
  * [[https://www.lakka.tv/|Lakka]] – transforms the Raspi into a full blown DIY retro gaming console

===== Windows on the Raspberry Pi =====
It's possible, but don't do it (yet).

===== Accessories =====
  * official Raspberry Pi power supply
    * supplies 5.1 volt which is useful because the Raspi draws a lot of uneven load and shouldn't be supplied with less than 5V
    * regular 5V power supplies drop their voltage a bit when the load is high or the cable is long

==== cases ====
  * [[https://www.raspberrypi.org/products/raspberry-pi-4-case/|Official Case]] – doesn't have good airflow/ventilation, nor a heatsink, nor a fan
  * Joy-IT:
    * [[https://joy-it.net/en/products/RB-Case+09B|LEGO Case]]
    * [[https://joy-it.net/de/products/RB-CaseP4+03B|magnetic case with dual fans]]

===== Sourcing =====
Since Raspberry Pis are currently (as of 2021/2022) hard to get[(see [[https://www.youtube.com/watch?v=Krpac-MaD5s|Jeff Geerling's video "You Can't Buy a Raspberry Pi — Why?"]] (October 2022) )], here's a site which shows where they are in stock: [[https://rpilocator.com/|rpilocator.com]].

===== Troubleshooting =====

== IRQ Balancing needs to many resources sometimes. ==

<file bash crontab># Restart IRQ balancer once a day
0 0 * * * root /usr/sbin/service irqbalance restart</file>

===== Further information =====
==== Videos ====
  * Jeff Geerling: [[https://www.youtube.com/playlist?list=PL2_OBreMn7FqeHztTB3BCMGJ_dx1jEK3f|Raspberry Pi Playlist]]