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.
Sub-Pages
Putting Raspberry Pi Monitor to Sleep (DPMS). HowTo: Turn OFF RPi Monitors (backlight too!)
GPIO Breadboard Worksheet - Used to document some of my projects. Breadboard contention!
RPi OS Alternatives - experiences and notes from tests of alternative operating systems & distributions
Earmarked for migration - will see how much of this moves to this site
Random, but occasionally useful RPi Links and Resources
Benchmark Comparisons on my fleet of PIs - CPU, IO & browser on RPI0, RPI1, RPI2, RPI3, RPI3B+ & RPI4
Harebrainers (potential recipes)
OccuPi - Remote controlled kiosk-like gizmo for my parents TV - Stalled
PanelPi - Integrate hardwired home security sensors into our IoT - Stalled
SmartiePi - Grandbaby is all grown up (4!) - her first computer! - In process
Struggles
(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
Watching this chatter: https://www.reddit.com/r/raspberry_pi/comments/qc4jad/did_i_damage_my_raspberry_pi_4_hdmi_issues/
Firmware could do this? https://github.com/raspberrypi/firmware/issues/1548. Have now worked with fresh SD/OS, updated/upgraded everything including eeprom. https://jamesachambers.com/raspberry-pi-4-bootloader-firmware-updating-recovery-guide/
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!
Stumbled upon ....
Article/Script to test power supplies AND CABLES:
@ https://bia.is/2019/02/02/raspberry-pi-check-your-power-supply/Some VERY GOOD background info:
@ https://ownyourbits.com/2019/02/02/whats-wrong-with-the-raspberry-pi/Another good article (and script):
@ https://jamesachambers.com/measure-raspberry-pi-undervoltage-true-clock-speeds/Official Power Supply Requirements:
@ https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#power-supplyBreakdown of vcgencmd output:
@ https://harlemsquirrel.github.io/shell/2019/01/05/monitoring-raspberry-pi-power-and-thermal-issues.html
Built new TesterPi image
Raspberry Pi Imager: Download/burn Raspberry Pi OS Light
Configure, install & boot
Raspi-Config: Hostname, WiFi, password, localisation & turn on ssh
apt-get update, then apt-get full-upgrade
installs (editor and sysbench): apt-get install joe sysbench
sudo reboot
via ssh:
Created ps-check.sh using script @ https://bia.is/2019/02/02/raspberry-pi-check-your-power-supply/
Sysbench 1.020: Slight mod to CPU syntax in script. Now looks like this:
sysbench cpu --cpu-max-prime=10000000 --threads=4 run &May as well bring in my tester2.sh over too ... script I used for Pi benchmarking
Also created picheck3.py python3 code using sample script from jamesachambers and the code from page on harlemsquirrel site. Stuck it on github to see how that works too @ https://github.com/tped/PiPower
Initial tests: Ghadzooks, this is interesting! I knew I had some crappy cables, but many surprises here ...
The Legrand Wall Outlets* I had installed in my work area are worse than I thought ... periodic undervoltage on RPI3B+ w/ known good cable
My USB Tester/Multimeter* sucks power (of course it does! :facepalm:) ... one step forward, two steps back!
Most of my USB-2 to Micro USB cables were pretty bad ... BUT worth saving for RPi 1B, 2 and RPi 0W
Canakit 3.5amp PS w/ PiSwitch* is probably my favorite for RPI 4 projects. Good price ($10) & solid
Argon ONE Raspberry Pi 4 USB Type C Cable Power Supply | 5ft 5.25V/3.5A*. Works great, little more $$ and no on/off switch
Smraza 5.1V 3A Power Supply for RPi 4 with ON/Off Switch & USB-C->MicroUSB adapter*. Doesn't look durable, but works fine w/ 90 degree plug to fit in a tight spot!
Throttling is not necessarily a problem: $h1t does happen! Example, our HomePi is rock solid, it runs and has done it's job for years ... a few reboots/year for updates and such. Over the course of months, vcgencmd reports that it has had at least one Under-Voltage, Arm Frequency Cap and has been Throttled ... the Pi is doing its job!
RPI 0W seems like it would run kodi videos using a hamster & wheel for power! Quite amazing ... everything seems to power it! Primary finding of this testing - CamperPi is now a RPi 0W and plays HD movies and Duke Nukem using a 5v 550mA power supply!
Unforgettables
(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
I will always need all the help I can get here ....
This month's fav tool @ https://regex101.com/
Python Regex @ https://www.w3schools.com/python/python_regex.asp
Regular Expression Analyzer @ http://xenon.stanford.edu/~xusch/regexp/
Regexp builder @ https://regexbuildertool.com/
Interesting Regexp Generator @ https://regex-generator.olafneumann.org
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Cheatsheet
Stuff to Research
WiFi Bootstrapping : Comitup+Dietpi [Works!], Comitup+Q4OS [TBD]
I often make Pi's for others - pre-configuring them for WiFi in someone else's home is a pain in the drain!
Gave Comitup a quick once over - there was a downloadable image @ https://davesteele.github.io/comitup/. It looks to be JUST what I need AND it WORKS!
Posted experiences with the downloadable image (RaspOS that boots up with Comitup) in Raspberry Pi OS Alternatives.
I am currently exploring installing/incorporating Comitup packages into my projects as opposed to starting with the image because I use a variety of OS underpinnings - Q4OS, DietPi, Manjaro ... it (comitup-1.15-1) seems to be in latest RaspOS which should allow me to apt-get install on everything except Manjaro. I don't see it in Manjaro or Arch AUR
Dietpi+Comitup:
Downloaded Dietpi ARMv6 32-bit. Uses the Raspbian package repository which provides comitup for install!
Booted on RPi4 to start with ... usual blow-by-blow
Auto updates itself & reboots - now at v8.3.1 - ~5min
Forced PW changes, disabled serial console
Dietpi config/software
Audio: Enabled, Sound card usb-dac (I'm going to mess with CutiePi enhancements)
Language/Regional: Locale en_US.UTF8, Timezone & us keyboard
Security: Set Hostname
Network/Adapters: Enable Wifi
Network/Other: Turned Off Boot wait for network (just to be safe)
Dietpi Software (season to taste: I installed stuff I want to live/play together): Shairport, Murmur, Raspotify, RPI.GPIO, python3, go, ALSA, GIT
Stuff I had to install by hand ... via ssh
My editor: good old joe - apt-get install joe
comitup from https://davesteele.github.io/comitup/ - apt-get install comitup
// Whoops! WiFi was disabled by default in Dietpi, comitup choked during install - Make sure you add Network steps in dietpi-config above //Whoops AGAIN! I forgot to RTFM @ https://github.com/davesteele/comitup/wiki/Installing-Comitup ... and I quote:
Allow NetworkManager to manage the wifi interfaces by removing references to them from /etc/network/interfaces.
Rename or delete /etc/wpa_supplicant/wpa_supplicant.conf.
The systemd.resolved service should be disabled and masked to avoid contention for providing DNS service.
The line dns=dnsmasq should not be in /etc/NetworkManager/NetworkManager.conf.
also changed default ssid in /etc/comitup/comitup.conf - now ap_name: <hostname>-<nnn>
I also added comitup to dietpi-services (right or wrong?)
comitup-cli is a useful command line tool here
Hey! It works!
Q4OS+Comitup
<next in queue ... I'd think it would work, raspos-based>