I’m a big fan of the RaspberryPi single board computers (SBCs) and have been using them since the very first model was released. (I still have the first model even now!)
Over the years I have used RaspberryPi computers for all sorts of things. These days I use them for running services on the local LANs here at home along with a number of virtual machines providing services both locally and publicly on the internet. (Yes, you can run virtual machines (VMs) on RaspberryPi computers)
I currently have 4 x RaspberryPi 5 SBCs running 24/7 and have had them stored in a simple rack that I designed when I first got into 3D printing. The rack worked ok but, it was difficult to get access to the Pi’s without removing those around the one I wanted to access. This is a real nuisance when you have services running on them all.
I’ve now had my 3D printer for a while and decided it was time to design a better solution. Before I set about diving into the CAD software I decided to have a look on Makerworld to see if anyone else had already come up with something more suitable.
The nice thing about this design is that each Pi module connects to the other using a simple sliding, locking pin system. This means that over time you can add more and more modules to the rack as your RaspberryPi collection grows. The other nice thing is that each Pi SBC is held on its own removable sled making it possible to remove each Pi with ease and without disturbing any of the others.
I downloaded the design into BambuStudio and went through all the component parts. I was really pleased to see that there were two sizes of module available, a single board Pi only module and a tall module for housing a RaspberryPi with a HAT installed.
Since the 4 x Pi5’s that I am using have either an NVME + 2nd Gigabit Ethernet HAT or a NVME SSD Baseboard installed I will need the taller module for each unit.
To make it easy to identify each SBC in the rack I printed each module in the same colour as the hostname of the Pi, bluepi, redpi, greenpi, orangepi and a spare slot for purplepi when I get it.
My RaspberryPi rack with 4 x Pi5’s in place and operational
These 4 little Pi’s work hard and CPU temperatures can exceed 50 degrees Celsius very easily. They all have the Official Pi Cooler with fan installed however, this doesn’t come on until the CPU reaches 50c and so I decided to added some extra cooling in the form of a small USB fan onto the back of each module. This reduces the operating temperature of each Pi down to around 25c under full load.
The purple slot on the end is a spare ready to house another Pi SBC. I’d love another Pi5 16GB model but, at the current ridiculous prices it makes no sense to invest in another and so I will fit my spare Pi4 into the slot for now and find something for it to do.
This has been a fun little project to print and put together and will provide the perfect solution to my Pi management woes.
I’ve recently built another AllStarLink node to compliment my personal 70cm band SHARI node as I thought since I have a full duplex dual band handheld it would be great to have another node that I could connect to FreeStar or HUBNet at the same time as monitoring the Matrix node.
Rather than build another personal node I decided this time I would build a public node, obtain a callsign from the RSGB and make it available to the HAM’s locally on the 2m band.
Initially I thought I may be able to use my old Retevis RT85 handheld and AIOC board for the 2m node but, after a little testing it soon became apparent that it overheats during long overs (which are common on AllStarLink) and so, I needed to find another solution.
AIOC connected to the Retevis RT85.
Chatting about this in the main Matrix HAM Radio roomSteve, M0XVT sent me a message saying he had an old Key KM-4000 converted PMR radio that had been reprogrammed for the 2m band that he was looking to sell and that it might be ideal for the new node. Wasting no time, we came to an agreement and I was soon the proud owner of a converted PMR transceiver.
Key KM4000 2m Band PMR Radio
The KM4000 transceiver has a standard output of 15w, 10w more than I needed for the gateway and so I had to reduce the output. A quick search on the internet and I found the Thames Valley Repeater Group website that had all the information required to turn down the output.
I also had to reprogramme channel 1 to the frequency and CTCSS tone allocated to me by the RSGB so that in the event of a power outage when the radio came back on it automatically jumps to channel 1 which would be correctly setup for operation.
Unfortunately the software for programming the radio is only available for windows and so I had to build a virtual machine running windows 10 to be able to reprogramme the radio.
Once this was done I rewired the AIOC USB audio device to work with the KM4000 radio and built the AllStarLink node on a spare RaspberryPi 4.
For an antenna I made a simple end fed vertical dipole from some RG58 coax and mounted it 8m up on one of my Spiderpoles in the garden. Running a coax feed out to the antenna I did some tests into the Parrot to get the audio levels setup and checked that the DTMF codes were interpreted correctly and that the node switched connections without error.
MB7IBW Internet Gateway hardware at the M0AWS QTH
Once this was done I had a few test conversations with stations on the Matrix node and FreeStar to ensure all was fine and then set the gateway status to “Operational” on the RSGB website.
This worked fine for a while with myself and some local stations using the node regularly but, then the hot weather arrived and things started to overheat. The transceiver was getting incredibly hot in the 30c+ summer temperatures and the power supply was also running extremely hot and so I decided to add some cooling.
Cooling the PSU was simple, it has a perforated top panel to which I strapped a cooling fan. This worked great and brought the temperature of the PSU down considerably.
The radio wasn’t so easy to cool. It has a solid case cover top and bottom and so cooling wasn’t going to be a simple affair.
I decided to remove the covers and drill some holes into them to allow airflow through the unit and strapped a fan to the top cover to pull the hot air out. This worked well however, on both transmit and receive I now had a warbling sound on the audio that was caused by the motor of the fan when powered up.
I found that lifting the fan up away from the case of the radio the warbling audio disappeared and things were back to normal and so, I decided to design a cooling tube to fit to the top of the radio to allow full airflow from the fan but, with the fan raised up away from the radio to resolve the audio problem.
Jumping into my CAD software I quickly designed a cooling tower to fit on the top of the radio that would allow the fan to sit far enough away from the radio so as to not affect the audio whilst at the same time pulling the hot air out of the radio and drawing cooler air in through the bottom of the case.
The cooler worked great with the radio staying cool to the touch and no longer overheating and reducing O/P power.
It’s amazing how much dust and dirt is in the air from all the farming activities going on at the end of our garden and how much of it is sucked in by the cooling fan. Regular cleaning is a must!
The MB7IBW Internet Gateway has been on air since mid June 2026 and has worked well. It spends most of its time connected to either FreeStar or HUBNet with connections to the Matrix Node when we have our nets.
Details on Frequency, CTCSS etc can be found under the MB7IBW menu above.
Sadly the initial interest from local HAMs has now wained and I am mostly the only user of the gateway. I was hoping more people would use it and bring some life to the 2m band, I guess time will tell.
It’s been a fun project and was interesting to go through the callsign allocation process with the RSGB representative. It was much easier than I thought it would be.
I now have all the parts to build another Internet Gateway for the 4m band. Hopefully that may attract some more interest. It’s certainly worth a try!
I’ve recently built a new AllStarLink (ASL) node for my MB7IBW gateway that I have recently brought up on air on the 2m band.
AllStarLink 3 has a lot of changes in it when compared to the previous version and this of course impacts my Node-Red Control Dashboard that I’ve been using to manage my first ASL node for well over a year now.
To build the node I used the RaspberryPi imager and added the AllStarlink 3 image as detailed on the allstarlink.org website.
Installing the system this way makes it pretty easy compared to previous installs but, it comes with some quirks which cause issues with Node-Red.
From the outset the plan has always been to have AllStartLink 3 and Node-Red running on the same Pi4 to keep it totally self contained. This was easy enough to achieve and works without issue.
Node-Red Control Dashboard for AllStarLink 3
Installing Node-Red onto a Pi4 is really easy and is fully documented on the Node-Red Website.
Once the AllStarLink 3 operating system was installed on my SD card, booted and operational I installed Node-Red. I soon realised that there were a few things I had to do before loading the Node-Red flow.
AllStarLink 3 no longer logs connect and disconnect messages in the connectlog like it did in AllStarLink 2. To get logging working again I had to create two new BASH scripts as detailed below and put them into /etc/asterisk/myscripts.
For the connect information I created the BASH script as detailed below.
Next I disabled the temporary filesystems that are used by default for the apache and asterisk logging as it’s useful to keep the apache logs for debugging and I needed the asterisk logs for the Node-Red dashboard.
Disabling the temporary file system is very easy to do, just edit the /etc/fstab and comment out the two lines as shown below.
# Comment out the next line for persistent Apache logs
#tmpfs /var/log/apache2 tmpfs defaults,noatime,nosuid,nodev,noexec,mode=0775,size=32M 0 0
# Comment out the next line for persistent Asterisk logs
#tmpfs /var/log/asterisk tmpfs defaults,noatime,nosuid,nodev,noexec,mode=0775,size=32M,uid=102,gid=106 0 0
# Note: These lines are wrapped, should be on 1 line in the /etc/fstab
Once the entries in the /etc/fstab were commented out I rebooted the Pi4 to get persistent filesystems.
The final thing that had to be done was to allow user repeater to use sudo without a password so that it could be used to perform reboot/shutdown/process restart as user root from within the dashboard.
# /etc/sudoers
# Allow repeater sudo without password
repeater ALL=(ALL) NOPASSWD: ALL
Once this was all done I imported the Node-Red flow, configured the SSH nodes with login credentials for the Pi4 (important to use the user repeater for SSH), clicked deploy and the dashboard was ready for use.
Node Red AllStarLink3 Control Dashboard Flow
I’ve been using the dashboard for a few weeks now and it’s running perfectly, without error.
If you want to build your own Node-Red Control Dashboard for your AllStarLink 3 node then, just download the flow using the button below and import it into your flow editor.
I’ve spent some time this afternoon modifying my Node-Red Dashboard for controlling AllStarLink nodes to work with the new AllStarLink version 3.
My original AllStarLink Control Dashboard was designed to work with AllStarLink 2 which I have running on an old RaspberryPi 3b on the 70cm band. The dashboard has worked reliably ever since deployment and is in use daily.
With the release of AllStarLink 3 and all the changes that it entails I’ve had to make a few changes to the dashboard flows in order to make it compatible with AllStarLink 3 nodes.
This entails not only flow changes but also the addition of two new bash scripts that are called by Asterisk to log connect and disconnect messages as they are not logged by default any more. (Seems a bit of a step backwards)
Node-Red AllStarLink Control Dashboard v3.0 for ASL3
The changes also entail disabling the temporary filesystems used by default in the new ASL3 build so that log files etc become persistent.
I’ll spend some time using the new dashboard to ensure it’s working correctly and then will release it into the wild for all those that are brave enough to move over to AllStarLink 3.
The articles I write for the blog are mostly technical but, I thought it was about time that I wrote this article as it’s been buzzing around inside my head for some time now.
So, what are the 5 things that I have found revolutionary in my shack that have brought new, exciting ideas and projects to life making amateur radio more enjoyable.
1: A RaspberryPi Single Board Computer
RaspberryPi 5 Single Board Computer
Ever since the first RaspberryPi Single Board Computer (SBC) was released I’ve been a huge fan. This little credit card sized number cruncher has been the base for so many projects, it has to be the first on my list.
The RaspberryPi SBC has been through a few iterations since its initial conception and is now powerful enough to take on most tasks that any radio HAM is going to throw at it.
So, what have I done with them?
Well I’ve used them to run Node-Red services for my many web app dashboards that control things like my QO-100 Satellite Ground Station, UPS power monitoring, Internet speed graphs, server and virtual machine monitoring, AllStarLink nodes, hosting websites, building an SDR shortwave receiver, running HAM Clock / Open HAM Clock, developing my own software, hosting virtual machines and a whole host of other fun and interesting things. I’m even writing this article using my RaspberryPi 500+ computer that is my daily desktop PC.
There are an endless number of things you can do with a RaspberryPi to bring new life and functionality to your radio hobby.
Want to get into Amateur TV? Want to decode digital modes real time? Want to track aircraft in the sky real time on a virtual radar screen? Want to search the shortwave bands for stations of interest? Want to host your own blog and website?
All these things and a lot more are easily within reach with a RaspberryPi.
The RaspberryPi is only limited by your imagination, the more imaginative you are the more your number crunching little friend will do.
2: A 3D Printer
Bambu Lab A1 Combo 3D Printer
Every HAM should have a 3D printer. These manufacturing marvels bring a new level of quality, design and simplicity to your HAM radio projects. I’ve found it incredibly useful since venturing into the rabbit hole that is 3D printing. When I think back to the weeks and months of my life I’ve spent making cabinets and boxes out of sheet metal, aluminium or wood for the numerous projects I’ve built over the years, a 3D printer would had made my life so much easier. 3D printing has revolutionised the making of things for the Amateur Radio home brewer.
There’s a multitude of useful things on websites like Printables, Thingiverse , Makerworld and others where you can just download the files and print high quality designs for all those things you’ve wanted to do but, don’t have the time or inclination to craft by hand.
The real satisfaction with 3D printing comes from designing your own things and making them. My first project was to design and print a fan cooling system for my Xiegu XPA125B amplifier.
From the factory the amp is passively cooled and doesn’t take long for the heat-sink to become saturated resulting in a high operating temperature. I was never happy with this and so was determined to resolve the problem.
Getting to grips with TinkerCAD was a bit of a vertical learning curve but, after a few mistakes and design mishaps I soon had it under my belt and pressed on with designing the cooler unit.
Designing the Xiegu XPA125b cooling system using tinkerCAD.
It’s not until you start designing and manufacturing things that you suddenly realise how much effort goes into them but, I persevered and over the period of about a week or so I had a perfectly fitting, operational cooling system that kept the amp super cool regardless of how long I waffled on for on the HF bands.
Once you’ve got your first design made you suddenly find yourself wanting to improve it and add things. In my case this was adding a Hermes Lite 2 holder to the top of the amp cooler and then a top shelf to hold my cross needle SWR and power meter.
Since then I’ve progressed massively with my designs and have even designed and printed things for other HAMs and family members, it’s totally addictive!
I can highly recommend the Bambu Lab A1 Combo (As shown above). It’s a quality piece of equipment that has operated faultlessly since purchase. Right now it’s printing a case for my RaspberryPi 4, just one of the many projects I’ve used it for since becoming a happy owner.
RaspberryPi 4 case from printables.com
Go on, release your inner creativity and treat yourself to a 3D printer, you won’t regret it and it’ll help you bring to life all of those radio projects you’ve dreamt of doing but, never got round to starting.
3: An AllStarLink Node
M0AW AllStarLink Node 61928 sitting on the equipment rack
Many people say that using VOIP over the internet isn’t real radio, I know because I used to be one of those people however, it has become an invaluable resource for keeping in touch with people all over the world.
Being part of an online HAM Radio Community it’s important that as a group we are able to talk to each other regardless of where we live, what bands we have access to and whether there is any propagation.
The AllStarLink (ASL) network gives global FM quality audio no matter where you are in the world. We use it daily for our breakfast net, general chatter throughout the day and even hold a weekly Matrix ASL Net on a Thursday evening.
Using our VHF/UHF handhelds (Real Radios!) and an easy to make AllStarLink Node we’re able to join in with the conversation regardless of propagation, licence type or distance, it really is great for bringing people together.
With devices like the SHARI and AIOC board now being readily available for minimal cost it really is very easy to get onto the AllStarLink network and talk to people even if you live in an antenna restricted location.
Why be alone when you can use the Matrix ASL node ( 642332 ) and join in the conversation.
4: Node-Red
M0AWS – Updated NodeRed QO-100 Dashboard with PTT button
Node-Red is a low-code programming tool for event-driven applications.
Node-RED’s goal is to enable anyone to build applications that collect, transform and visualise their data; building flows that can automate their world. Its low-code nature makes it accessible to users of any background, whether for home automation, industrial control systems or anything in between.
I’ve been using Node-Red for a number of years now and have developed a suite of web app’s that control and monitor just about every aspect of my Amateur Radio hobby and IT infrastructure.
Node-Red forms an integral part of my QO-100 Satellite Ground Station providing control of both the uplink and down link radios whilst synchronising the VFO’s, controlling filter selection and more, all from one simple to use interface using nothing more than a web browser.
It doesn’t stop there, my AllStarLink (ASL) nodes are also managed through a user friendly Node-Red Dashboard that removes all the need for technical know how and makes ASL node management as simple as clicking on a button to connect or disconnect to the many global networks.
Much of this functionality is achieved without writing a single line of code. If you can use a mouse, drag and drop objects on the screen you can develop Node-Red web app’s, it really is that easy.
M0AWS Interactive Log Flow
It doesn’t end there, Node-Red is great for presenting data in easy to digest formats.
Whether it be HAM Radio Log data presented on an interactive world map or monitoring of your server, RaspberryPi, virtual machine or UPS using gauges and graphs, this can all be achieved easily with nothing more than a mouse. There’s no need to spend hours writing thousands of lines of code, just drag and drop a few nodes onto the screen and join them up. You’ll be amazed how easy it is.
I believe every Amateur Radio enthusiast should have Node-Red available in their radio shack. It’s easy to install on your RaspberryPi 4 or 5, Linux or Windows PC and Apple Mac with the same great functionality available on all platforms.
Once you’ve developed your first web app you’ll suddenly find a million more ideas will come into your head and before you know it, you’ll be where I am today with Node-Red at the centre of your radio hobby.
5: A Hermes Lite 2 HF SDR Transceiver
For years I used black box HF radios from the big 3 manufacturers along with the odd radio from the smaller enterprises like TenTec but, they all had their foibles and there was often nothing I could do about it.
My last acquisition from the big 3 was a Yaesu FTDX10, a competent hybrid SDR radio with a good receiver however, the menu system is terrible, the button layout not much better and the user experience not as good as it could be. Of course the software is closed source so there is nothing you can do about it. The radio did its job but, it wasn’t fun to use, it wasn’t what I really wanted and it didn’t put a smile on my face.
I looked at moving to software defined radios (SDR) but, with prices in the many thousands of pounds bracket and the software being closed source I came to the conclusion that they wouldn’t give me what I really wanted either.
So what was it that I was searching for?
Thinking long and hard about it I came to the conclusion that what I really wanted was a radio that gave me the same satisfaction that OpenSource software has given me for decades, namely an HF radio that I have complete control over, from the hardware through to the software and everything in between.
I wanted something that I could tailor to my exact needs. Something that was built using open hardware and open software, something where if I wasn’t happy with it I could change it, improve it and do the things I wanted with it.
At this point my search for the ideal radio headed in a completely different direction.
Xiegu XPA125b Cooler with Hermes Lite 2 cradle – front view
The Hermes Lite 2 SDR HF Transceiver (HL2) has been around for a number of years. I was first introduced to it by Michael, DK1MI and then Roger, G8VLR via the Matrix. Both Michael and Roger use the HL2 on a regular basis and have often waxed lyrical about how good it is.
Being designed by radio amateurs for radio amateurs it’s based on an open architecture from the ground up. Being an OpenSource junky this really appealed to me and as I looked deeper into it from both a hardware and software point of view I soon realised that it had the potential to be exactly what I was looking for.
It wasn’t long before I found myself on the Makerfabs website placing an order for the HL2 mainboard, filter board, I/O board and case. A couple of weeks later it arrived and I dived head first into the SDR rabbit hole.
2 years later and the HL2 has become my main HF radio in the shack. Partnered with a Xiegu XPA125B amplifier and PiHPSDR software running on my Kubuntu Linux PC it is everything I have been looking for in an HF radio.
I’ve made modifications to the software to suit my operating style and needs with the user interface being exactly how I want it, no unnecessary buttons or knobs, just the controls that I use on a daily basis cleanly placed in a logical, easy to use layout, the way I want it.
My understanding of software defined radio and how it works has improved a hundred fold. Having access to the software and being able to go through the code and understand the architecture has been an interesting journey and one that has enhanced my radio enjoyment considerably. I now have a smile on my face every time I go on air.
Do I miss the FTDX10?
No, not in the slightest!
So, those are the 5 things that I feel have revolutionised my radio amateur hobby and made it a more enjoyable experience. I’m sure over time I will add to this list as I venture down future rabbit holes in our wonderful radio hobby.
I’m sure there are many radio amateurs around the world today who have an old handheld radio sat on the shelf that works perfectly but, has been replaced by a new, shiny, all singing, all dancing model that gets used on a daily basis. I for one have fallen into this trap with the recent purchase of a very nice Wouxun KG-UV9K full duplex 2m and 70cm handheld.
On my shelf there is a cheap Retevis RT85 that gave sterling service for a number of years and even today is ready to continue that service, if only I had a need?
Well now I do!
Currently I have an AllStarLink node running on a RaspberryPi 3b connected to a SHARI device that operates on the 70cm band. This node works great and gives me the ability to chat with people all over the world from my trusty handheld. It does of course also give me access to the weekly Matrix AllStarLink Net that happens on our Matrix node ( 642332 ) every Thursday evening at 20:00 UK time, a great way of bringing the Matrix HAM Radio community together regardless of propagation.
For some time I’ve been wanting to bring another AllStarLink node online so that I can have a connection to HUBNET/FreeNet whilst keeping my current node connected to the Matrix node for our regular daily chats. Since my new Wouxun handheld is a full duplex unit it makes sense to bring a new node up on the 2m band as I can then monitor both at the same time easily. I do have a spare SHARI node however, it’s a UHF only unit and I don’t want another node on the 70cm band. This is where the old Retevis RT85 comes in to play.
The AIOC board really is tiny but, beautifully put together. The four large solder pads on the top and more on the underside are positioned such that the TRS plug solder lugs line up perfectly for soldering. Attempting to do this by hand would be impossible as it’s critical that the spacing between the two connectors matches that of the spacing of the sockets on the radio.
AIOC Solder Jig.
Searching online I found a very handy soldering jig on Github that enables you to hold both the TRS connectors and AIOC board in the perfect position for soldering.
Downloading the .STL file I quickly printed off a solder jig on my Bambu Lab A1 Combo 3D printer and fitted the components into place ready for soldering.
Fitting TRS connectors into the AIOC solder jigFitting AIOC board into the solder jig.
Everything fitted rather snugly into the jig and I soon had the board and connectors soldered together. Test fitting to my Retevis RT85 I found the TRS plugs lined up perfectly and it slid into the sockets with ease.
I then thought about designing a case for the AIOC board so that the bare circuit was nicely protected but, quickly searched online and found that NA6D has already designed a case and made the .STL available publicly for download on Printable.com. I quickly grabbed a copy of the file and punted it off to my 3D printer to get to work on.
3D print NA6D AIOC case.
Once the print was complete I fitted the AIOC board and snapped it together ready for testing.
Fitting the AIOC into the 3D printed case.AIOC case with 2 x TRS connectors in place.AIOC case USB-C view
Now that the AIOC was production ready I moved on to getting the latest version of AllStarLink onto my RaspberryPi 4 that I had taken out of my RadioBerry based shortwave receiver that I am going to upgrade to a Hermes Lite 2 in a later project. The RaspberryPi 4 is perfect for AllStarLink 3, a 64bit app and operating system.
Using the RaspberryPi Imager I pulled the image down onto an SD card and slipped it into my Pi4. ( Instructions on how to do this are on the AllStarLink website here )
Booting the Pi4 for the first time I found that it went through a number of reboot and configuration cycles before it was ready for use.
AIOC connected to the Retevis RT85.AIOC connected to the Retevis RT85.
Once ready I went through all the normal configuration of the Pi4 namely, static IP assignment, timezone config, security, port forwarding etc etc.
Having configured an AllStarLink node for myself and only just a few days ago for another HAM I was pretty familiar with the setup. Wanting to make sure there were no “gotcha’s” I also watched a couple of KM9G’s videos on Youtube to make sure I wasn’t missing anything.
Using the asl-menu command line app as user root I set about configuring Asterisk to work with the AIOC board. Much to my frustration I could not get Asterisk to recognise the AIOC board as an available sound device. I checked and double checked all the settings ensuring that I had selected “AIOC” in the available devices menu but found that Asterisk constantly errored saying it could not find the selected audio device. This went on for a whole day without success and so, I decided to put it to one side and come back to it later, a method I found that often worked.
A couple of days later I revisited the problem and had decided to take a different approach. Rather than continue going through the asl-menu app I decided to drop down to a lower level and go through the asterisk config files in the /etc/asterisk directory.
It wasn’t long before I found a file called res_usbradio.conf. Inside this file was the config for the AIOC board however, it was all commented out which meant it was disabled.
I’m guessing here but, I imagine this is what should get enabled when selecting AIOC in the available devices menu in the asl-menu command line app but, for some reason it doesn’t happen.
[general]
;usb_devices = 1209:7388 ;comma delimited list of usb
;descriptors to allow.
;format vvvv:pppp in hexadecimal
;vvvv=vendor id, pppp=product id
;
;1209:7388 = AIOC (all in one cable)
Above is the disabled configuration which is easily edited to enable the AIOC device as shown below.
[general]
usb_devices = 1209:7388 ;comma delimited list of usb
;descriptors to allow.
;format vvvv:pppp in hexadecimal
;vvvv=vendor id, pppp=product id
;
1209:7388 = AIOC (all in one cable)
Once the updated file had been saved and I restarted Asterisk using systemctl the AIOC burst into life and Asterisk recognised it immediately. The Retevis RT85 switched between TX and RX and I was ready to check out the audio.
Setting the volume levels for both RX and TX via the command line tuning app I connected the node to my already existing node. Sure enough the two nodes connected without error and I was able to send and receive audio between them via the AllStarLink net.
Connecting the new node to the parrot I checked the audio levels to ensure it sounded ok and then connected it to the Matrix node where I had a brief chat with Ben, M8TKK.
All that is left to do now is to 3D print a case for the Pi4 so that it isn’t left naked and at risk of being shorted out on conductive surfaces and it’ll be ready for service.
I also plan to build another AllStarLink node using a 4m band handheld and another AIOC board and then will apply for MB7Ixx callsigns for the two new nodes. This will hopefully help to bring some life to the 2m/4m bands locally and introduce HAM’s both to the weekly Matrix Net and HUBNet/FreeStar via AllStarLink.
Living in a rural area we have a very unreliable mains power supply and so I have to protect all the IT equipment in my home lab with an uninterruptible power supply (UPS).
Over the years I’ve found APC UPSs to be super reliable and use them extensively around the house to keep important services running during power outages.
Running a combination of Debian and Ubuntu operating systems on my servers and virtual machines (VMs) I’ve always used the apcupsd daemon to interface with the UPS for automated shutdowns etc.
The apcupsd daemon does have a very simple web interface that can display 3 items of information at a time but, I decided it would be nice to have a view showing all the information on one dashboard.
Node-Red APC UPS Flow
The Node-Red flow is pretty simple and is based around the apcrequest node that connects directly to the apcupsd service on port 3551.
Note: You must configure the apcupsd service as a NIS server in the /etc/apcupsd/apcupsd.conf config file.
Most of the info is collected via the apcrequest node however, I found that getting the events information via the node to be unreliable and so I used a BigSSH node to connect to the computer to get the UPS events information directly from the log file.
The simple flow collects the data, formats it into a useable format and then passes the data on to the dashboard GUI objects for display, it really is very simple.
Node-Red APC UPS Dashboard
The resultant dashboard clearly displays all the information needed including line voltage over time. I was surprised to see such a swing in the incoming voltage but, now understand why I get so many low line voltage and over voltage events on the UPS.
The events log is displayed in a scrolling text area on the dashboard with colour highlighting.
If you’d like to create a dashboard for your APC UPS then the flow can be downloaded below.
Following on from my previous article on using Node-Red to build interactive log maps I’ve now reworked the flow to make it more efficient with less Javascript.
The original flow had a function that handled the issue of FT4 contacts being recorded in two different ways depending on which app you use for your FT4/8 operations.
<mode:4>MFSK <submode:3>FT4
or
<mode:8>MFSK FT4
The code I wrote to handle this wasn’t particularly elegant and so I decided to remove the code entirely and just use a simple change node.
M0AWS New node to handle FT4 more efficiently
This is the great thing about Node-Red, there’s always more than one way to do something.
With this fix in place and the old code stripped out of the format generic payload function, the new flow is much tidier and easier to comprehend.
M0AWs Updated ADI Log Map flow
With testing complete and the two maps now live on my website the flow is finally ready for release into the wild.
If you fancy presenting your ADIF logs in a more visual, interactive format then just download the flow below and import it into your Node-Red flow editor.
Don’t forget that you will need to change the path to the log files in the file read nodes to suit your setup and change the location data in the My QTH trigger to match your callsign and location. Other than this the flow should just work.
I’ve not been on the radio much over the last few weeks as I’ve had my head down other radio related rabbit holes.
One of the rabbit holes is a Node-Red project to make my online logs a little more interactive. For sometime now my logs have been displayed on my website as nicely formatted, searchable HTML pages however, they don’t really allow the viewer (myself included) to see the global coverage of all the contacts so, I decided to write a Node-Red flow that would do just that.
M0AWS Interactive Log Flow
The flow itself isn’t too complicated and basically consists of reading in the individual ADIF formatted log files, processing the data and then sending the data in the correct format to the map node for display.
I’ve had to write a few functions to handle the processing of the ADIF formatted data but, these aren’t particularly complex and are fairly easy to understand even if like me, you’re not a Javascript programmer.
The flow is working perfectly however, I’m in the process of reworking the format generic payload function to reduce the amount of code and make it more efficient.
M0AWS SSB / CW / FreeDV Interactive Log World Map
M0AWS Interactive Log Map Layers Menu
The flow generates two maps, one for voice / CW /Satellite contacts and the other for WSJT-X FT4/8 contacts. Every pin on the map is colour coded by band with satellite contacts being denoted by a satellite icon.
Each pin / icon on the map is clickable and reveals the data of the QSO being displayed.
In the top right-hand corner of the map there is a drop down layermenu that allows the viewer to filter by band thus reducing the number of icons on the screen at any one time.
Seeing the data presented on a map really brings my logs alive. An example of this is that I had no idea I’d worked so many stations in India on the QO-100 Satellite.
The small icons in the pins show a microphone for SSB/FM/FreeDV contacts and a downwards pointing triangle in a box for CW contacts. Sadly I couldn’t find a Morse key icon in the collection available.
M0AWS filtered view of QO-100 Satellite contacts
I only use FT4/8 for testing new antenna designs however, it’s interesting to see the global coverage accomplished with this weak signal mode.
M0AWS WSJT-X FT4/8 Interactive Log World Map
Once I’ve finished rewriting the format generic payload function I will make the flow available for download here so that others can also create an interactive view of their radio logs.
If you want to have a look at the maps and try them out for yourself, they are available under the Logs menu above.
This Node-Red instance is running in a virtual machine (VM) on a 16GB RAM RaspberryPi 5 that is also running a number of other VMs at the same time so, it’s safe to say it’s not heavy on CPU and will run on the older Pi4 as well.
RaspberryPi computers are now moving into the realm of being powerful enough to replace the traditional desktop PC. My most recent purchase, a RaspberryPi 500+ is proof of this as it has been my daily desktop PC since it’s arrival.
One of the things I use heavily are virtual machines. They’re great for developing, prototyping and running new services. With the ability to snapshot, rollback and backup in an instant, virtualisation helps to reduce the development and test time for many of the programs and services that I’m playing with.
With RaspberryPi computers now supporting 16GB of RAM and M.2 SSD drives there is no reason for not taking advantage of virtualisation.
To this end I decided to test running some virtualised loads on my new 500+ with the plan to deploy to 16GB Pi5’s with SSD drives in place of more expensive Intel based computers.
On my Intel based machines I use QEMU, KVM and Virt-Manager to manage the multitude of virtual machines (VMs) I have running here. Since this is a solid, high performance platform for running VMs I decided to take the same route on the 500+
Installing the necessary packages is extremely simple, just one simple apt command:
# Main ethernet
# Setup Bridge called br1 on eth0
allow-hotplug eth0
iface eth0 inet manual
auto br1
iface br1 inet static
address 192.168.0.100
network 192.168.0.0
netmask 255.255.255.0
broadcast 192.168.0.255
gateway 192.168.0.1
dns-nameservers 192.168.0.5
bridge_ports eth0
bridge_stp off
#
#
Once this is done reboot your RaspberryPi and check you have access to your local LAN and of course the internet. You will now also inherit the two new groups that you added yourself to above.
Note: If you are using NetworkManager open the network settings app and create a bridge on eth0. You can also use the nmtui copmmandline app if you prefer.
At this point you’re ready to create your first virtual machine.
It’s important to have an arm64 version of Linux in ISO format that you can use to install into your VM. My preferred distro is Debian and so I downloaded the Debian 13 Arm64 netinst ISO from the debian.org website.
From the main menu start “Virtual machine Manager” or on the commandline type:
virt-manager
QEMU Virtual Machine Manager
Click the Create new VM button and then navigate to where you saved your ISO file and select it as the installation media.
Virtual Machine Manager – Local install mediaVirtual Machine Manager – Select ISO file
Once you’ve chosen your ISO you’ll need to configure the actual VM. Start by setting the amount of RAM and number of virtual CPUs you want the VM to have.
Virtual Machine Manager – Configure RAM and CPU
Next set the size of the virtual disk that the VM will use.
Virtual Machine Manager – Create virtual disk
Finally, give the VM a name and set its network device to br0 as created above. Click finish and your VM will boot.
Virtual Machine Manager – Name VM and select bridge interface
Now it’s just a case of going through the standard Debian install process to build your Debian VM.
Once the installation is complete and the VM has rebooted you will have a functional Debian computer ready to use for whatever you like, just like a physical PC but, in virtual form. You’ll find that the VM runs as fast as the actual physical machine thanks to the kernel based virtualisation.
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