Category Archives: Raspberry Pi

Raspberry Pi Shortage

Raspberry Pi Shortage

Let’s talk about the Raspberry Pi shortage.  Pi’s of just about any variant have been close to impossible to get since Covid entered our lives.   Particularly difficult to get are the Raspberry Pi 4 of any memory configuration or the Compute Module 4 (CM4).

I particularly like the CM4 for the fact that an SSD can be added to it and that it can have a Real Time Clock (RTC) depending on the Carrier Board you use.

Raspberry Pi Shortage

Server Rack Full O’ Pi’s

A few weeks ago I scoured through all my parts piles and disassembled all my old projects and found a ton of Raspberry Pi 3’s.  To my utter surprise I found I owned SIX Raspberry Pi 4’s.  But they were mostly 1GB and 2GB models.

I also had FOUR CM4’s.  Sadly most of the CM4 Carrier Boards you see out there are either lacking in functionality or are simply vaporware.  The official Raspberry Pi IO Board is almost the only real choice.

You would think this is an adequate number of Pi 4’s and CM4’s for me, but it isn’t.  I’d have a couple of Pi’s in every room, doing various jobs if I could get my hands on more.
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OP25 Revisited

OP25 Digital Decoder Revisited

About 5 years ago I was DETERMINED to figure out a digital voice decoder software program called OP25.  It literally took me a year to figure out how to do it.   I’d work on it for a day or two then give up.  Then try again a week or three later.   Then one day I heard the crackle of a police call over my speaker.   It was at that moment I decided to take what I learned and wrote a dummies guide about it.   To this day,  it is still the blog that gets the most hits, and attention.  And that blog is mostly still relevant.  It pretty much works in the same way.

Just last night I took my old OP25 installation and noticed that it was on Raspberry Pi OS “Buster”.  I tried to upgrade it to the current distribution code named “Bullseye” and things rapidly began going south.  Before I fouled it up too bad I downloaded 4 files:

  • – a script file I made to launch the program
  • trunk.tsv – a file that tells OP25 what Frequency and NAC to listen to
  • newbern.tsv – my local configuration for the police talk groups here
  • viper.tsv – the NC statewide talk groups

I decided to start fresh and within about 20-30 minutes I had a fresh installation of Raspberry Pi OS and OP25 running.  I think I can streamline my installation process a bit more.


I have absolutely nothing to do with the development of OP25.  I’m just the guy who wrote the dummies guide on it.  And I’m doing it again.
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Oh My God I Got A Raspberry Pi 4

In the last year I have bought exactly TWO Raspberry Pi’s.   They have reached the status of “Unobtanium” thanks to world wide chip shortages and supply chain issues.  It takes dedication to find one, much less purchase one.

It used to be that you could buy one whenever you wanted to buy one.  Those days are gone.  I got a Pi 4, 2GB from Adafruit on a fluke.  I really only want 4GB or 8GB Pi’s but you take what you can get.   And once you find one …….. you can only order ONE.

I guess I should consider myself lucky but every day that goes by I get more and more disgusted with Raspberry Pi.  The last couple questions I asked on their forum I got asshole answers.  One gent provided no help and told me to “Learn Python”,   He must be related to Joe Biden who told all the unemployed coal miners in West Virginia to “Learn To Code”.

I usually like having several spare Pi’s laying around so when I see a project I can just get right to business.  As it was though for my last two projects I had to take a couple projects out of service because of the lack of Pi’s I have.  I had to ditch my OP25 Police Scanner on the back of a TV and my GPS PPS clock used as a local time server.  I’ve also been replacing some of my Pi 4 Media Servers (logitechmediaserver) with older Pi 3B+ models.

Anyway, I’m +1 on Raspberry Pi’s at the moment and probably will put OP25 back together and redocument the process if it has changed.

And no, I’m not gonna learn to code.   But the hunt for next Pi is on.  This one only took 3 months.  Ridiculous.

GPS Tracker For $10 A Month With Raspberry Pi


I have a little pop up A frame camper and I’m always afraid it is going to drive away.  Camper theft is a thing.  Clearly I needed to get or make some sort of GPS tracker.

There are a lot of ways to do this, and some better than others and I dare say that the way I’m doing it may not be the best way, but the way I’m doing it ensures economy.  And by that I mean not consuming excessive cellular data.

I really thought I’d slap a 4G HAT on a Pi and Real Time Track with a SIM card.  It’s really not that easy and I learned a few things along the way.   The first thing I learned is that real time tracking uses data and unlimited SIM cards are generally in the $60 a month range.   So the smart play (at least for my situation) is to have the Raspberry Pi text me its position on a semi regular basis.  Remember, if it is stolen I only need to use the GPS tracker to track it down once.

Before I go into details let me preach on it.

So I started with:

This works but there is one gigantic problem.
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I’ve been on a Raspberry Pi project tear lately.  Somehow or another I stumbled into BirdNet-Pi and the best way I can describe it, is that it is like Shazam for bird songs.   It records the call and frequency and plots it on a spectrograph and identifies the bird.

Very Cool!

About a year ago I married my long time girlfriend and we bought a new home just outside of town.  We are on a 1 1/2 acre heavily wooded plot that also has a creek running along one edge.  So the birds love it here.  And my wife loves birds and keeps the feeders clean and full.  So I really did this for her but this project has got me super excited about all the different species of birds around here and their distinct calls.

It’s easy as heck to build.  You need:

  • Raspberry Pi – latest is best however I built this with an older Pi 3 B+.  It runs fine on there.
  • SD card to install Pi OS.  BirdNet-Pi says to use Pi OS 64 bit Lite.
  • USB microphone.  Initially I used an $8 USB mic  and it works but the better the mic…….the better the results you’ll get. I used a Rode mic that costs about $50.
  • OPTIONAL – if you use the better microphone you will need a USB Sound Card. to plug the mic into.  The better mic and sound card make the project a bit more expensive but I think you’ll be glad that you went that route.  if you just want to dabble then just use the cheap mic.

NOTE ON MICROPHONE:  Because the Rode mic I linked above costs $50 and it is a directional microphone I did some research and found an omni-directional mic that costs $20 less.   It is a Lavalier Clip On mic.   I’ve had it up several hours and my bird call detection is WAY up.

That’s it.  Install Pi Os 64 bit Lite with Raspberry Pi Imager.  Be sure to hit Command +Shift + X (Mac) (probably Control + Shift + X on windows) before you write the SD card. This allows you to  set up wifi and change the hostname  and change the timezone and set up SSH if you want.

Pi Imager

Lets proceed!
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Building a Fast Pi File Server

I just did a blog on booting a Pi 4 Compute Module from an NVME drive.  I’ll provide a Build Of Materials (BOM) for duplicating this project.  Here are the primary components:

Compute Module 4 Build of Materials

ComponentCost Description
CM4008000$75CM4 Lite 8GB No Wifi, No Bluetooth
NVME PCIe Adapter$11NVME Adapter
Samsung EVO 970 Plus 2TB$203NVME Drive
CM4 IO Carrier Board$35Carrier Board for CM4
SD Card$9SD Card (optional). Not required if your CM4 has eMMC.
Power Brick$9Power Brick. Just picked the first one I saw on Amazon. Any 12v , 2 amp or more will do. Get a 5.5mm connector.

So for just over $300 you can have an amazing file server.  Also if you back off the 2TB Samsung EVO970 to a 1TB drive you can save $100 roughly.  You can buy a cheaper Compute Module as well IF YOU CAN FIND ONE. A 2GB one is fine for serving files. For around $200, or a bit less you can have a solid, and adequately fast file server.
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Booting a Raspberry Pi CM4 From an NVME

This is another one of those things………..All the information is out there.  Several good sources have blogged about it, but NO ONE has put it in a Dummies Guide for the rest of us to follow.

NVME support and NVME booting is now built in to Raspberry Pi OS.  If you have a Compute Module Lite you can use the SD Card Copier program to copy your SD card to your NVME drive and boot to the NVME by removing the SD card, however if you have a Raspberry Pi 4 Compute Module with eMMC you have to change the Boot Order according to the docs


It’s not hard to do this.  And even if you use an SD card it might shave a little time off the boot to not have it looking for other boot sources first.  I recommend doing the following steps anyway so the NVME drive is first in the boot order.

First and foremost I will assume you have a booting Raspberry Pi CM4:

  • Raspberry Pi CM4 either with eMMC booting or via SD Card. (This example will be from SD) I have an 8GB with no WiFi or Bluetooth.
  • NVME PCIe Adapter – This one works fine.
  • SSD NVME – Bang for the buck I recommend the Samsung EVO 970 Plus I’ll be using the 2TB version of this card.
  • A micro USB to USB cable.
  • Power supply of 12 volts and probably a minimum of 2 amps.  I am using an old router brick that is 12v. 1.5 amps with no issues so far.  I do recommend around 20 watts of power for the board, adapter board, and SSD.

Once booted up normally with the adapter and nvme drive connected let’s check to see if it is recognized with these two commands:


lspci and lsblk results (click pic to enlarge)

You can see the nvme drive is detected.  Good!

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Is It Time To Abandon Raspberry Pi?

The Raspberry Pi is a single board computer that came out in 2012 and cost $35.  The intent was to teach computer science and coding to school age children.  The program and the Pi itself  is (or was) a raging success.  Hobbyists flocked to the low cost board that ran Linux and created myriads of projects that were fun, useful and educational.   I’ve been raving on them since 2012.

I’m ready to stop raving.

Why?  Because you can’t get them anymore.  To exacerbate things even more the CEO of Raspberry Pi (Trading) Ltd. came out on April 4th on their website and said that current production was going to businesses that have their livelihood dependent upon Raspberry Pi.

I’m sure a more reasonable translation is “these are our biggest money producing customers and phooey on the individual consumer”.  That is of course my quote.

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Raspberry Pi Compute Module 4 Boards – Where Are They?

Pi Compute Module 4

The Raspberry Pi Compute Module is an interesting concept mostly designed for embedded solutions.

A regular Raspberry Pi gives you an HDMI slot, a camera slot, GPIO Pins, USB, audio, etc. but a CM4 with the proper board can give you a PCIe slot, onboard SATA, or onboard NVME M.2

But where are those boards?

I’m looking for a board that will do NVME M.2 natively for a 3.15″ SSD.  I simply can’t find one.

You can take the official Raspberry Pi IO Board and add a PCIe adapter to achieve this but it is kind of a kluge the way it sits in the slot and to date I’ve seen no specific cases that would hold the board securely.

Plus if you give up that PCIe lane to the adapter you can’t use it for other cool things.

What’s a geek to do?

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Raspberry Pi Compute Module 4 NAS With SATA Card

I got the inspiration to build up this Raspberry Pi NAS with a Compute Module and SATA adapter from Jeff Geerling.  His blog page is here (linked with permission).  If you like Raspberry Pi even a little bit this guy pushes the Pi to the extreme.  His computer, networking, and Linux skills are exceptional and his delivery is easy to understand.  If you visit his blog click the YouTube icon on the right side of the page and visit his channel.  

Decided to turn my Pi Compute Module 4 into Network Attached Storage (NAS).  A real NAS.  While a Raspberry Pi NAS won’t light the networking world on fire it is more than adequate to serve up files.  I want to put this NAS out in my Shed for two reasons.

  • Redundant backup in case the house burns down
  • Use Squeezelite client to stream audio to my shed stereo, a circa 1980’s Technics Receiver.

I have a mini-ITX case and guts to put a “real” server out there but my shed is a woodworking shop and push come to shove I’d rather gum up the fan and overheat  $100 worth of Pi and Compute Module IO board than to blast a $450 server motherboard.  Besides lots of sawdust it gets wicked hot and wicked cold in the shed too. This computer is going to get dirty and this is a choice of economics as much as anything.

Making a Pi NAS is easy but it also ends up being a spaghetti mess and unless you design and 3D print a custom case the Compute Module just isn’t organically designed to fit any standard case out there.  We gotta get creative.

My cheap case is a Mini ITX case.  How I dealt with the installation was to keep the 500 watt power supply intact and to 3D print a case for the Compute Module IO board.  Then I just double side taped that to the inside of the enclosure.  Here’s a quick video of the build with details to follow.

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