Pi In The Sky

Simply a work area and/or catch-all for miscellaneous Raspberry Pi tips, tricks, tools, tweaks, research or harebrainers - most-likely a mess, but potentially useful to others.  Initially weeding through remaining Raspberry Pi info @ ventures.tpedersen.net/errata/raspberrypi to salvage useful  info.


Earmarked for migration - will see how much of this moves to this site


(Ongoing or Solved Issues/Oddities)

RPI 4 No HDMI Output

 Oct 2021:  First RPI Hardware issue?!  SmartiePi RPI4 board from June 2021 has lost ability to emit HDMI signal.  Runs fine if I SSH into it, but cannot get HDMI output to save my life!   Pi has been used headless for past 6 months or so.  When reconnected to HDMI there is NO signal/output.

22 October:  FIXED!  It was the damn CASE!  NO hdmi cable or adapter would work (and I tested a quite a few!).  Finally removed the case and POOF!  The cable clicked in a nano farther and it came right up!   VERY bizarre, RPI 4B was mounted in that case the day it arrived, worked fine right out of the box!  I can also see the case is no longer available on Amazon.

Others w/ similar issues

Pi Power

Mini Project - A tangent while on my quest to build CamperPi that will provide low-power/offgrid entertainment.  I also have a pile of questionable RPi power supplies that need to be weeded through - I keep plugging in bad ones!  THEY NEED TO BE TOSSED!

Jan 2022 - Built a contraption to test cables and PSU's ... I had a mess on my hands!

Built new TesterPi image 

Initial tests:  Ghadzooks, this is interesting!  I knew I had some crappy cables, but many surprises here ... 



(Stuff I should remember)

Check for Installable or Installed packages

Find a specific package via apt-cache search <package>

List of ALL installed packages (pipe to grep or page thru) via dpkg -l

SSH:  Remove offending key when a IP is reused

ssh-keygen -R <ip> 

Regular Expression (Regexp) Stuff

Stuff to Research