John's Musings

Yeah, Me Neither

New Blog Location

I am transitioning. No. Not like that. A new blog site!

Decided to transition from RapidWeaver and Armadillo blogging software to Wordpress and also decided to lock it down with https. See ya on the other side.

A Strategy For Fixing Your Own Appliances

Just fixed my dryer and I'm always a proud poppa to know I DID IT MYSELF and saved big money. My symptom this time was a massive CLICK, CLICK, CLICK sound as the dryer was running. After popping the hood I could easily see the belt was breaking and causing the noise. Then when I took it apart and removed the drum I found a seized up roller mechanism which probably caused the strain which broke the belt.

Let's talk about appliances first. If you are reading this blog you know I'm a geek. I like geeky things that can be controlled over the internet or via wireless. Even though that's my style I refuse to buy white goods (Refrigerators or Washers and Dryers) that contain computers. YOU DON'T NEED IT. A washer agitates and spins, and fills up and empties water. A dryer gets hot and goes around and around in one direction like a NASCAR Driver.

Back in the day when us Americans were 'Muricans we made our own stuff. And we made it with big wire wound motors that could last beyond the Second Coming of Christ. We made our own bearings, Washers and dryers were made of steel. Components were simple, robust and they made millions of spares.

Whirlpool made refrigerators and washers and dryers with exactly the same parts and then put them in various enclosures with different styles and paint schemes and sold them as multiple brands. Maytag, Admiral, Whirlpool, etc. But make no mistake, they were the same item.

Even today the world is full of spare parts for these things and they are CHEAP. The belt I just bought for my dryer was $8 and I paid too much. Probably could have gotten it for $3 on eBay but I bought from Amazon because I needed it fixed quick.

Don't buy something from Korea that has a computer in it. Just don't. You need your refrigerator to work for years and you need it to not blow up when the power flickers. Think about what those dimming lights then sudden surge of power back to the house does to sensitive electronics.

Now lets talk strategy. Your appliance has failed.

First get the model number of your appliance. Note the Revision number (mine is 11). That matters.

Now what is the symptom? Washer won't drain. Dryer doesn't get hot. Refrigerator isn't cold.

Then google "LNC8764A71 Clicking Sound" or whatever the symptom is. I PROMISE YOU there are a dozen or a few dozen videos on how to troubleshoot. If you watch a couple of those videos you'll be a stone cold appliance repair expert. One of my symptoms was "da belt be breaking" so I spun the tub by hand and sure enough the belt was a wreck, barely hanging on to life. So now I know I need a belt.

Go to a site like and then put in your model number and then you'll see something like this:

Scroll down to the Tumbler section and find the belt. It is item 5. NOTE: There is a tumbler section for Rev 12. Remember I told you the Rev number mattered? In my case I DON'T want Rev 12.

Now scroll down to item 5. BAM $13 and it is yours. You can order the part right there.

See the Whirlpool part number there though. Google that part number or go to eBay with it. I found it for $6 on eBay all day long. Try to stick with genuine OEM parts and please know that if you buy a GENUINE OEM PART on eBay from China..........well it probably isn't a genuine OEM part. Use your common sense. if the seller is some old appliance repair guy (as most of these are) you can have confidence.

Again find that YouTube video for changing the belt. Many of these repair web sites like have repair videos as well. Watch a video like this one below and you won't be scared to try to change the belt yourself.

In my case it was literally

  • lift top on dryer and lay it back
  • remove two screws on the frame
  • disconnect dryer door switch
  • pull off door
  • remove drum
  • remove old belt
  • reverse process

15 minute job with NO PROBLEMS at all. Except one of my rollers wasn't rolling smooth. I removed it and cleaned it and greased it.

Anyway if you call the repairman you're going to pay him $100 just to show up. He's going to replace the belt that he probably paid $3 for and charge you $150. Meanwhile you can buy a new dryer for $300 or so as long as it isn't a fancy aluminum one with computer boards in it.

Here's my dryer with a shiny new belt installed.


LimeSDR - Mini on Ubuntu with GQRX

Getting the new LimeSDR Mini working on Ubuntu with GQRX was a bit challenging. These are the rough steps

  1. Install LimeSuite
  2. Install udev-rules
  3. run GQRX with sudo (I've since noticed this doesn't seem to be mandatory.)
  4. Run GQRX as "other" with device string as "driver=lime,soapy=0"
  5. Set bandwidth to 20 MHz and input rate to 2.5 Msps
  6. Set antenna to LNAW

Install Limesuite as follows:

sudo add-apt-repository -y ppa:myriadrf/drivers
sudo apt-get update
sudo apt-get install limesuite liblimesuite-dev limesuite-udev limesuite-images 
sudo apt-get install soapysdr soapysdr-module-lms7

Install GQRX as follows:

sudo apt-get purge --auto-remove gqrx
sudo apt-get purge --auto-remove gqrx-sdr
sudo apt-get purge --auto-remove libgnuradio*
sudo add-apt-repository -y ppa:bladerf/bladerf
sudo add-apt-repository -y ppa:myriadrf/gnuradio
sudo add-apt-repository -y ppa:gqrx/gqrx-sdr
sudo apt-get update
sudo apt-get install gqrx-sdr

Download udev-rules and install OR build LimeSuite from source. Although i have downloaded the source I am ONLY installing the udev-rules.
cd LimeSuite.git
cd dev-rules
sudo chmod +x

Start GQRX as sudo. Your LimeSDR-Mini should start flashing its LED green wildly about now. That means GO!

sudo gqrx

Set up as follows:


For some odd reason if you remove the dongle and re-install it, it may or may not work again. If you do manage to try everything like 10 times and get it to load again every single time you will have to set the Antenna and Hardware AGC. Very odd behavior. The driver is still wonky. And my directions here are not foolproof. Sometimes it works, sometimes it doesn't. I've found myself having to open LimeSuite and connect to the LimeSDR-mini and hitting Default and disconnecting. Not sure if that does something or not. Again as I stated above I've noticed that GQRX doesn't have to be run as sudo. I have found that sometimes all is well the first time you run GQRX and other times you have to open and close the program multiple times before the driver loads correctly.


A Newbie's Primer for SDR Radio

I like to think I take a very common sense approach to things and I also like to think I take note of THE SMALL THINGS. So what I'm shooting for here is that you're new to SDR radio, and you see all these fancy SDR's and you wonder which one to buy but you'd like a common sense shakedown to SDR so you don't waste a ton of money (as I have. Oh boy, have I).

First of all ......... Welcome. SDR is AMAZING. You are surrounded by radio signals all day and all night, every day and every night. If it is a signal people have at least attempted to discover what it is and decode it if it is in fact encoded. So what is out there? AM and FM radio for sure. No surprise there. Short wave radio, CB radio. HF radio. VHF radio, UHF radio. that includes but certainly not limited to, Police, Fire, Ambulance, Aircraft, Airport beacons, pager traffic, ships at sea, tracking of Aircraft transponders, tracking of ships. Tracking of satellites. Wireless headphones. The baby monitor, your tire pressure sensors, your key fobs, wireless doorbells. Your smart gas meter emits a radio signal. You can tune in to the local NOAA weather frequency as in my pic below. You can use an SDR to detect whether there is a wireless transmitter SPYING ON YOU. etc, etc, etc.

I probably left off 25 other great things. Ok. You'd like to try. At the very least you can listen to FM radio and I do just that thing in my office. Radio's are cheap but an SDR is a CONVERSATION PIECE. Nobody will say "Nice Radio" if you have a table top radio in your office but if you have an SDR with GQRX streaming a big signal people will say "WHAT'S THAT?"

So you'd like to try SDR. Which one do you buy? The age old question. The first thing I'd recommend is to spend some time on which is the definitive website for SDR radio. Read the forums, browse through the really great articles and then try to answer the question.....


Well I promise you that no matter what the first thing you'll do after you get one is tune into a known audio signal that you can readily identify just to see if the thing is working. And for most people that is going to be a local AM or FM radio station. Once you master that you'll just find yourself drifting around trying to identify signals that are out there and sometimes you'll get lucky and hear audio, like from an aircraft overhead or from a Ham Radio on an analog channel.

So let's get back to the million dollar question. What are you going to do with it? Are you a HAM radio operator? Or a CB enthusiast? Are you a military geek or an airport geek? Perhaps you're somewhat of a spy and think you can listen to the neighbors cordless phone or their baby monitor............

Most folks will probably want to jump in cheaply to see if they like it. No need to spend $200 on an SDR only to figure out you have no idea how to use it.

I strongly recommend starting the hobby with this device. I call this one "The Blue One" It's almost the cheapest one out there.

Technically it is an RTL2832U and it works like a champ and even has a little antenna with it that is suitable for most very general and very local listening. The principal advantage of this receiver is that it is inexpensive. The main disadvantage of this is the frequency can vary a little bit with heat which means you usually have to provide a correction value in ppm before it is displaying perfectly accurate information. In my experience that is only an issue when you do more advanced stuff.

I have one of "The Blue Ones", take that back, I have several of the blue ones. One I use in my office to just plain old listen to FM radio and VHF radio traffic. I work at a Marine Corps Air Station and I'm a civilian tech rep that supports aircraft recovery operations. Translation: I can listen to the tower and ground controllers at the Air Station on one of these. Here's my best SDR military story. When an aircraft approaches an airport it can tune to something called ATIS. That is the robot dude voice that says what the airport conditions are, what runways are open, if there are any closures, if the radar approach systems are up or down or what frequency they are on, if the visual landing aid systems are on or off. You know, all the stuff a pilot wants to know....... I'm a Visual Landing Aid tech rep and one day I hear the ATIS call one of my systems as being non-operational when I know darn good and well that it is functioning perfectly. I go tell the Operations guys who say "Thanks......pause........hey, how'd you know?"

I also use the blue one with something called Pi-Aware. Airplanes release transponder signals on 1090 MHz called ADSB. You can track aircraft and even be a feeder station to Flightaware. It looks like this:

That's pretty cool, huh? A $35 Raspberry Pi and a $15 SDR and you're tracking aircraft. I've been running my station for a couple of years.

So the "Blue One" is all you need to have a little fun and for most people it might be enough. Now the Blue Guy won't go below 25 MHz or so and quite frankly there is a lot of cool stuff to be heard below 25 MHz. For starters basically all of Ham Radio and short wave radio. Also your AM radio is down there as well. Can't listen to AM radio on the Blue Guy. If you want to download NOAA WeFax transmissions, yep, you guessed it, that is down below 25 MHz as well. How about Digital Radio from other countries? Yep. Below 25 MHz.

To get below 25 MHz you need an up converter. This is a good one. The Nooelec Ham It Up Upconverter. Slap this between the Blue Guy and the antenna and suddenly you are listening to Amateur Radio and short wave radio in all its glory. So that costs another $40-$50 or so and it doesn't even have a case.

Isn't there an SDR that does those lower frequencies and the higher ones? You betcha there is! The RTL-SDR v3

This will go from about 0 MHz to about 1.3 GHz or so. That is huge. HOWEVER, there is a big however here...... Natively the device tunes to about 25 MHz lowest which is the same as the blue one but you can tune it down lower by doing something called "Direct Sampling" which means you apply a device string command in software such as GQRX and an LNB offset value and viola' you are listening to Amateur and Short wave radio. Another caveat here is that once you apply those values you are stuck between 0 and 25 MHz until you put your settings back to "normal".

If you are a newbie I bet you have no idea what that means and I explain it better here. Ok this is getting complicated. Isn't there an SDR that tunes to the lower bands AND the upper bands without having to be a computer scientist?

Again, you betcha there is. It is an SDRPlay RSP 1, RSP 2. As of this writing the RSP1 is discontinued however I bet you can still find them. An RSP 2 will set you back about $170 though. Suddenly it gets expensive but remember you want a device that is simple to use. SDRPlay RSP2 is an AWESOME device however if you are using anything but Windows it becomes not so awesome. Building software and installing drivers for Linux or Mac is a very involved process but nothing a geek can't handle.

The RSP 2 software is called SDRUno and it has a bit of a learning curve but it is extremely powerful once you've learned it. Another gigantic advantage of the RSP2 is it has a huge useable bandwidth of 10 MHz. That means if you are using your SDR as a scanner it can cover 10 MHz worth of frequencies. One of the most popular scanner programs is called SDRTrunk but alas the RSP 2 does NOT WORK with SDRTrunk. I'm pretty sure that it doesn't work with the other popular trunking program which is called Unitrunker.

Welcome to Suckville. Population: You.

So the RSP 2 is just as sweet a device as can be but because of the drivers and software development it doesn't play nice with all the software. My understanding is that the SDRPlay software, SDRUno will soon have scanner support. And that's COOL! But again, SDRUno is Windows only. If you are a Linux geek like me you're still kind of left in the dark.

If you need 10 MHz of useable bandwidth to make a police scanner you need to investigate getting an AIrspy R2. Looks like it is just about at the end of its support life and Airspy will be selling a newer device soon. Airspy plays nicely with SDRtrunk and Unitrunker so having an Airspy in my opinion is preferable to having an RSP 2 (for trunking scanners).

What's the bad news about the Airspy R2? You know there is bad news, right? Airspy R2 doesn't go below 25 MHz and you need an up converter to use with it. Their upconverter, the Spyverter. The price for an Airspy and Spyverter.............$250 or so. Oucheth. But by and large you can do more with Airspy and it comes with a free software program called SDR# that is probably the best SDR software out there that there is. Sadly it is Windows only and I generally despise Windows. But push come to shove if I really want to do something tricky I'll grab the Airspy and my Windows laptop.

These are all receivers. If you decide you need to transmit, well number 1 you need an FCC license and number 2 you need something called a HackRF, an Adalm-Pluto or a LimeSDR or LimeSDR-mini

I won't say much about the transmitters because this is a primer for newbies but an Adalm Pluto needs special drivers that generally have to be compiled and built and it again doesn't play with all software natively. Ditto for LimeSDR and LimeSDR-mini. I just bought a LimeSDR-mini and it is barely useable because the software and support just isn't out there yet because it is so new. HackRF works with pretty much everything and it has 20 MHz worth of useable bandwidth. If you want to dabble with transmitting but you're still a newbie do yourself a favor and buy a HackRF.

To recap briefly. An inexpensive SDR will do most things however it won't tune below 25 MHz. You need an up converter to reach those frequencies. An inexpensive SDR that will do direct sampling and reach those HF frequencies is available but it is just a little geeky to get working and once you are set below 25 MHz, you are stuck there until you undo what you did to get there in the first place. To have it all costs bigger money but having bandwidth and a giant frequency spread means little if the software support isn't available.

Buy a cheap stick, play, learn a little and THEN AND ONLY THEN, spend the money on the greater receivers.

1. If you just want to dabble pick up a generic RTL-SDR as cheap as you can. There are a bunch of different ones out there and they all work. Some better than others.

2. If you want to inexpensively listen to HF, Shortwave, and Amateur Radio buy an RTL-SDR v3.

3. If you want HF, Shortwave, Amateur radio and want to listen to VHF and UHF without having to set device strings and LNB offsets buy an SDRPlay RSP2 or RSP1A.

4. If you want to follow trunking radio systems such as your local police, fire, ambulance, city services buy an Airspy R2.

5. If you want to transmit and do cool experiments like trying to break into your own car by hacking the keyfob buy a HackRF.

6. If you want to track L band satellites and the such get the SDRPlay RSP2 or RSP1A (or Airspy).

I probably own 2 dozen SDR Radios. If I had to start fresh knowing what I know now I'd buy generic ones for long term projects like PiAware. I'd buy an Airspy and Spyverter for bigger game, and I'd buy a RTL-SDR v3 for the laptop bag for traveling.



Squix e-Paper Weather Device

Who doesn't check the weather everyday? Most have a favorite website or just check the local news. The folks at WeatherUnderground have an exportable Weather API that can be used with Internet of Things (IoT) devices. I built another device recently with a little color OLED screen and it's cool but it is a battery hog and dies frequently. Then when you turn it on it goes through this updating routine that leaves you waiting 20 seconds or so to see the weather. Heck I could check 2 websites in that amount of time.

Thingpulse sells a 2.9' e-paper display that is really neat. If you don't know what e-paper is then you're in for a battery saving treat. E-paper holds your screen image even with no power. That allows you to refresh the device at intervals and use almost no battery whatsoever. And the display is always on.

The 2.9" display costs $50 but get this.........that's all you get ............AND............alone it does NOTHING. You have to program the onboard ESP8266 IoT device with some Arduino code of some sort to make it useful. Then you have to 3D print a case for it. That's why I love this. I love projects. Anyone can buy something that already works. Give me something that I have to inject code into that I can change.

Here's the board (swiped their photos).

All the directions for programming the board are here and I won't re-invent that wheel by reposting the directions. The funny thing is that nowhere in those directions do they actually tell you to turn the board on with the switch. I tried to flash the code 3 or 4 times before I scratched my head and said "I wonder what THIS switch is".

Then this is in the directions but so non-chalant as to be easily missed. Before you program the board it must be in Programming Mode. Duh. Push GPIO 0 button, then push RESET button, then let go of RESET button then let go of GPIO 0. Now you can write the code.

In the instructions it tells you to download the Arduino program and that you must have an FTDI controller (CP2102). I bought my controller from here. You will also need some female to female breadboard jumper wires as well. So already this is a project for someone that has a bunch of electronic junk laying around. And suddenly the price creeps up if you don't have all this junk laying around.

I won't go too deep into the instructions as again their instructions are ALMOST perfect. I will say this though........they don't get specific enough about the arduino code that you program in. The code is located here and you download the zip file. Once unzipped you open the espaper-weatherstation.ino file.

Once you get that opened then go the "settings.h" tab in the Arduino Program.

In "Settings.h" insert your wi-fi credentials. Be sure to put it between the quotation marks.

Now scroll down and change the Weather Underground settings. Note that I have the WeatherUnderground API key blacked out. You have to add your API key that you created between those quotation marks.

Also notice that I have settings for "Boston". The section just above was what was enabled giving me UTC time. I wanted local time. You have to add the hash marks before the work "struct" to disable something. And also note that the # in front of the word "define" has to be there. So you have to remove some hash marks and add them to the other section. Simple as can be, right?

Lastly just below the bottom red circle notice IS_METRIC value. Mine was set to true. That means the temp came back in Celsius. Change that word to false if you want Fahrenheit.

To print a cool 3D case for the display go to this link on Thingverse.


pfSense Hardware Firewall

I am always blathering on about network security. The only real security is a firewall. Your router that you bought on Amazon or at Walmart is NOT secure. Look at the box. It says it is FAST. It doesn't say it is secure. Furthermore there is a sticker on the bottom of it with a WiFi password that looks like this:


That's awesome. It really is.

So then you plug your router into the cable modem which attaches it to the INTERNET via direct physical connection. Guess what the password is for that direct physical connection?

Answer: password

I'm not fucking kidding. Every router out there has a default WAN password that is something stupid like password or actually no password. And silly you thinks that long wifi password makes you secure.

Probably the BEST non-enterprise firewall out there is something called pfSense. And best of all it is FREE. You can download it for free. You just need some hardware to install it on. You can take an old desktop computer and put an extra ethernet port in it and you are ready to rock however the big old desktop will be on 24/7 and will probably jam your power bill up more than it is worth. What you really want to do is get a small hardware appliance that sips power.

One way to do it is to buy an appliance from pfSense. They are a bit pricey though but you are also buying support which you may need as pfSense is a bit geeky. pfSense is basically FreeBSD Unix. FreeBSD is probably the most stable and secure operating system there is. The internet backbone that you use every day doesn't run on Windows. It runs on Unix and Linux. It is rock solid stable.

One of the "gotchas" in using a computer or getting an appliance is that the next version of pfSense will require the CPU to support the AES-NI instruction set. So if you spend your money and your hardware does NOT support AES-NI you will not be able to update.

I previously had a pfSense Netgate SG-2220 (and by the way it is for sale now). It still works, it has AES-NI, etc. Just if you know me I have to have the latest and greatest is all.

One way to keep costs down a bit is to buy a mini appliance. I bought a Minisys E3845 Quad Core device from here Got it for about $230. The nice Chinese company that ships it even sends it with pfSense installed!

Uh......yeah..........I totally trust a preinstalled firewall from China. I also trust my 401K to Hillary Clinton and Mexican tap water.

Best to blast that OS to the moon and install a fresh copy. Go here to download. Also to do this you'll need a USB keyboard and a VGA cable to a VGA monitor.

Configure your download like this:

It will download a compressed file with a .gz extension. Unzip that compressed file and inside will be a file named:


Get yourself a USB thumbdrive and a program called Etcher and burn the image file to the thumbdrive. From there you set your Minisys to boot from the thumbdrive and follow the install routine. Follow these directions. I'm not going to write them out. These are great instructions.

You will have to set port assignments after it boots. Set as follows

WAN = em0

LAN = em1

that corresponds to LAN 1 and LAN 2 respectively on your Minisys.

Now plug this bad boy in directly AFTER your cable modem using the WAN port (LAN1).

Now plug your router in to the LAN 2 port.

You can access and control your firewall from going to a browser and pointing to

at first the credentails are:

user = admin

pass = pfsense

For God's sake change these. At this point you have a decent hardware firewall.

Oh yeah there is tons of configuring you can do. You can add ad blockers, and all manner of protection programs such as Snort, Squid, and pfBlockerNG. I encourage you to read up on that stuff, there are guides galore on the internet. if I can figure it out, so can you.

But just as is you're running a fairly tight ship with just the hardware firewall. You probably won't keep North Korea or the NSA out but you'll keep most of the common hacks from penetrating your network. Is it perfect? No. But it is TEN THOUSAND times better than plugging a router full of security holes and no password up to the internet.


JumboSpot DMR Hotspot

One of the latest crazes in the world of DMR radio is the Chinese iteration of the DMR hotspot. The principal attraction? Low cost. The Jumbospot costs about $45 and I've heard tales of people getting them for $35. Slap it on top of a Raspberry Pi Zero W which costs $10 and an SD card and you are on the air for about $70 or so if you factor in everything. Add a $9 OLED display and you still haven't broken the bank yet.

So JumboSpot is cheap and like it or not this is the way that a lot of people are going to go. So I ordered one.

To tell you the truth I didn't expect much, heck I even expected that it might not work but I was up and running in 20 minutes and much of that time was spent soldering the firmware header pins on and the antenna connector. I had read several horror stories on the internet regarding Jumbospot (which many call "ChinaSpot") and they are downright scary. Then after working through it myself it is fairly apparent that the problem here is the Linux and Raspberry Pi aspect of it. Many people just don't know or understand Linux, Linux networking, etc. And it is a bit daunting if you have never been exposed to it before. And plan on doing a little soldering. They don't even come with the antenna connector on them. At least mine didn't.

Also it seems to me that there are Jumbospots on eBay that have subtle differences. You might be best served to buy one from where at least you can send it back if it doesn't work. I bought mine from eBay and paid $45 for it. So lets take it out of the anti-static bag and lets prepare the hardware. Bust out the soldering iron.

NOTE: If you intend to solder an OLED display to the JumboSpot beware that some OLED pin arrangements are GND, VCC, SCL, SDA. The OLED's that I have here have this arrangement. Be sure your Vcc (Voltage) and GND are not reversed before you install and solder.

Also mine came with no ceramic antenna soldered on the board. This is good because most folks are removing them anyway.

Solder a 2 pin header to Pins 38 and 40 of the Pi. Your Jumbospot will work fine without these two pins but you will NOT be able upgrade the board firmware without it. I don't want to get too technical here but pins 38 and 40 are the corresponding Pi GPIO 20, and 21 pins. Here's one of the lines from the script file that update the firmware.

(sudo stm32flash -v -w 7021_HShat.ino.bin -g 0x0 -R -i 20,-21,21:-20,21 /dev/ttyAMA0)

You might notice there a lot of 20, and 21's in that command. That's where the action happens folks. No 2 pin firmware write.

Okay.......We have a 2 pin header on pins 38 and 40 and our SMA connector is soldered to the board. Lets prepare the software. We're going to use Pi-Star OS which is basically Debian Linux or Raspbian Raspberry Pi OS. Go to the Pi-Star download website It will download a zip file. Here's one of the big problems with burning the image.

UNZIP THE FREAKING FILE! Inside the zip file is a file with a dot img extension (.img). That is what goes on the SD Card. Make sure to Download the RPi file (if you are using a Raspberry Pi. If you have no clue how to burn the image look down the page and there are guides for WIndows, Mac, and Linux.

I'm going to make it easy for you. I have a Mac and the command is called "dd" . That is the old Unix/Linux command called "Disk Destroyer" so since many folks reading this page will undoubtedly be angry if they follow this guide and wipe their hard drive on their computer I'm not going there here. I'm serious. If you put the wrong device number down for your device you'll wipe and re-write your hard drive, back up drive, whatever. a program called Etcher Point it to your Pi-Star Download image file. FOR GOD'S SAKE UNZIP THE FREAKING FILE. DON'T BURN THE ZIP FILE. DID YOU HEAR ME?

Then select your SD card reader and hit the flash button. Takes 5 minutes or so. And then you are DONE.

Now..............before you remove that card go back to the Pi-Star website and go to the WiFi Builder page Insert your credentials and hit the "submit" button.

LEAVE THE SD CARD IN .........find it in the file manager and stand by to add a file to it.

Once you hit submit it will download a file called


SIMPLY DRAG AND DROP THAT wpa_supplicant.conf FILE TO YOUR SD CARD. At the first boot up your JumboSpot / RPi combo will connect to your wifi. I hope you know by now the Pi Zero W has to have a 40 pin male header soldered to it as well.

Install the JumboSpot on the Pi

Now you can get on the SAME wifi network with a computer, open a browser and scroll to pi-star.local/

Be sure to include the dash. If for some reason THIS DOES NOT WORK, clear the cache in your browser and try again, especially if you've had other pi-star devices connected before. If that doesn't work open a terminal (in Mac it is called terminal, in Windows it is called CMD for command prompt) Then type

ping pi-star.local (this time WITHOUT the trailing dash)

You'll notice that it answers WITH THE IP ADDRESS. So in this case just point your browser to (your IP address is going to be different).

At this point you need to configure Pi-Star. I'm not going to go too deep here. Initially you will be asked for a password. The default user name and password is:

user = pi-star

pass = raspberry

I'm not going too deep here but to configure Pi-Star for DMR essentially just add the following at the configuration page:

Select MMDVMHost

Simplex Mode

DMR Mode

If you have an OLED soldered on add it here by using the drop down box

Your host name can be anything. Just leave it at pi-star

Add your Callsign

Add DMR ID (initially this will not be on the first configuration page. It will have you reset the modem then you can add it)

Add your Simplex Frequency

Lat/Long/Altitude is optional but nice to add.

Hit auto for URL and it will add your callsign

Use the Radio/Modem type I have selected

Set Time Zone

Set your BrandMeister server. I use 3102 most of the time.

Color Code is 1


OK! Congrats! You should be talking to people by now. Now lets upgrade that firmware. This is tricky stuff.

Navigate to Expert mode in the browser using this address:


Then select SSH Access and login using your credentials. (pi-star, raspberry)

Once logged in follow the directions on the screen and type in this command


That lets you in write mode so you can update the firmware.

Now issue these commands to upgrade the firmware:

cd /usr/bin 
sudo wget 
sudo chmod 755

after the last command it will write the firmware and re-boot the JumboSpot/Rpi. Here's something not mentioned. Once you download that firmware file ( the next time you go to download a firmware upgrade Linux will probably name it hsfw(1).sh or something like that. I'm not positive but that's probably what will happen. At any rate you do not need the file after the firmware is flashed so for general housekeeping and tidiness (not Tide Pods) let's get rid of it. Again log into SSH ACCESS first.

cd /usr/bin
sudo rm -r

You are good to go and running the latest firmware. And be sure and call for KN4FMV on TG 3100 USA if this helped you at all!.

*****************************UPDATE 12 FEB 2018*****************************

Finally received the proper OLED and soldered it in. Works as advertised.

Also got one of the aluminum cases that they sell on eBay. Looks nice and professional.

You can say or think anything you want about the JumboSpot but this simple fact remains. They cost $45. Because of the price of competing hotspots people are going to buy these. They work. The OLED and case are cheap and look GOOD.

Before you jump too deep in my some people have already, look around my blog page. I own an OpenSpot, a DVMega, and a Zumspot (so far). I'm buying the other ones with my own money and I am writing about them too.

Building The Perfect DMR Beast

Thanks Don Henley for the Subject Line inspiration.

Decided to transition my Raspberry Pi / DVMega combo into a proper enclosure. I had previously just printed a Pi/DVMega Case which was fine and all but a proper enclosure is a completed project and a conversation piece.

I've included a Build Of Materials (BOM) but only included major items. There are a few things that you'll also need to include some hook up wire, a USB cable with a micro-USB connector on one end that you use to power the Pi. You'll have to cut it and wire it to the Output on the Power Supply. Also i didn't include an SD Card for the Raspberry Pi.

Also I've left off a small kit of stand offs. These are invaluable for a variety of projects.

Ok, so here is the Build Of Materials. You don't have to use these exact parts. Almost everything can be substituted including the DVMega. You could use a Zumspot or the dreaded JumboSpot (Chinese Clone of MMDVM_HS board).




Raspberry Pi 3


Can substitute Raspberry Pi Zero W. To utilize older Pi variants you will require a USB WiFi Dongle

USB to TTL Conv.


There are others you can use but this one is inexpensive



UHF only

Buck Power Supply


There are multiple power supplies that can be utilized to power the Raspberry Pi. Pi Requires 5v and 2 amp minimum (recommended)



Shipping costs $16.40. Hey, still cheap for this enclosure

D.C. Input Connector


Bag of 25. Hard to find just one. Can order singles from Mouser or Digikey

Ant. Panel Mount Connector


SMA male to SMA Female

Power Switch


Pack of 10. Mouser or Digikey for single panel switches.

Nextion 2.4


Must program screen for DRM with HMI file.



Must 3D Print

Optionally, since the box is so freaking big you could add a panel mount ethernet connector on the back to just hook it up to your home network and not rely on wireless. If you go this route realize that you'll need a short hunk of Cat 5 or better cable. I have a spool of cable and connectors and an RJ-45 tool so I can make my own cable that is the perfect length.

Wow! Where to start. Probably the first thing you want to do it program the Nextion 2.4" screen. I have directions to do this here. Once you have it programmed you'll have to cut a hole for the screen in the front panel and fit the bezel into it. It's not too hard. I did it by tracing the bezel, drilling holes on the inside of the lines and cutting with a hacksaw blade in a handle. It's not rocket science and the bezel is wide enough to cover tiny mistakes.

Then you need to mount the Raspberry Pi on 4 stand offs. Make sure to give yourself access to the SD card, the Pi power micro USB connector and leave plenty of room for the FTDI USB to TTL Converter.

Before mounting the power supply take a micro-USB cable and cut the appropriate length to reach between the Pi and the place where you intend to mount the power supply.

A micro-USB cable has 4 wires (and 5 pins). The wires are as follows:

  1. Red - Vcc 5 volts
  2. White - Data Transmit
  3. Green - Data Receive
  4. Black - Ground

We only need the red and black wire to carry power to the pi. So prep the cable like this and tin the ends of the red and black wire with solder.

We're not transmitting data or doing any mode detection here, we're just sending 5 volts to the Pi.

Before you connect this and plug it in make sure your power supply output is 5V

Hook the red wire to the + side of the output on the power supply and hook the black wire to the - side of the power supply.

The pic below shows the output side of the power supply. Again lets not power this up just yet.

Ok now lets wire up the power supply. Right for the moment let's keep it simple. We can add a switch later. On the DC input jack are two legs. Place the red wire on the short leg and the black wire on the longer leg. Apply the red wire to the IN+ and the black wire to the IN-

DO NOT have power routing from the output terminals to the Raspberry Pi at this point. We need to adjust the output voltage first. You'll need a power brick with a 5.5 mm connector on it. The power supply goes from 4-32 volts DC. Obviously you need something more than 5 volts. Tons and tons of old electronics hardware around the house probably have 12 volt or 18 volt bricks on them. You probably have 10 laying around the house on stuff you don't use anymore.

Once the proper voltage is obtained you can connect the Raspberry Pi.

Essentially this is all you really need to do to be up and running. Once you plug it in it should power up beautifully and function.

At this point you can wire in a switch and fuse if you want. To add a switch just take the red wire from the DC input plug and put it on one terminal of the switch. Continue the other leg on the switch to the IN+ on the power supply board. The black wire still goes from the long let of the DC input plug to the IN- on the power supply board.

An external antenna cable can be added at this time as well. I swiped that small antenna off of another radio I have laying around the house and it may just be that this project remains with an internal antenna. Haven't made my mind up yet.

Since this thing occupies a lot of space no real reason for it to be using WiFi. Might as well hard wire it. Ordered that panel mount ethernet connector and installed it. Works great.

And just for a nice finishing touch I added a dust cap to the ethernet port.


A Newbie's DMR Primer

Bear in mind that I am a DMR newbie of sorts and this is a blog from the new dude discussing his opinions on DMR goodies and gotchas. I may get a technical detail or two wrong but I bet if I have this impression many other newbies would too.

There are two ways to connect to DMR.

  1. Digital Repeater
  2. Hotspot

Let me briefly discuss my understanding of connecting via a repeater. First of all your radio must be in range of the repeater. Once in range the repeater will have certain talkgroups that can be programmed into your radio. Here is an example from the repeater list. So if you are in the range of this repeater on Hoosier DMR these are the talkgroups that you can talk on when connected to this repeater.

Here's the closest repeater to me below. By the way I cannot reach this repeater from my home but can connect to it from in and around my office. This connects to the PRN DMR network.

So just for comparison if I want to talk to someone on the repeater in Muncie Indiana I'd have to do it on TAC 310. So simply you are a bit limited in talkgroup channels if you key in through a repeater.

The 2nd way to connect to a DMR network is via a hotspot. You use the internet to get into the DMR network. The most common way to do it is via the Brandmeister network. The Brandmeister network has some crossover with the DMarc network and such local networks as PRN which is the one closest to me. But Brandmeister has the MOST talkgroups. They are segregated dozens of different ways. If you want to get on DMR, and your goal was to talk to someone in Wyoming about the weather your best bet is Talk Group 3156, Wyoming Statewide. Here's the US BrandMeister talkgroups. Don't forget they have groups in other countries, and world wide groups etc. There is seemingly no limit to the groups you can listen in on or talk on.

The biggest problem with hotspot is that it is only as good as your internet connection and won't work at all if the internet breaks, gets hacked, EMP burst, etc.

That being said I think that most of us newbies are going to go the hotspot and Brandmeister route. So now you need a hotspot. I'm going to list some pros and cons of some of the more popular ones.

SharkRF Openspot

This might be the most popular hotspot out there (for the time being). And for good reason. It just works.

I bought one of these and initially didn't like it and I'll explain more about that here in a bit. I've grown to love it now though.

OpenSpot Pros:

  1. Attractive and well constructed
  2. Easy to connect
  3. Boots and connects fast
  4. Built in operating system already installed
  5. Easy to find on the network (sometimes)
  6. Can calibrate it for best modulation between your radio
  7. SharkRF has a opensource server program for Linux you can run to create private channels. (Very cool) I set one up here.
  8. Can cross platform between DMR and Fusion. You don't need two separate radios.

OpenSpot Cons:

  1. Expensive
  2. No Wifi. Ethernet Only.
  3. Web interface only. Cannot add OLED or Nextion screen.
  4. If set to DHCP it changes its IP address frequently
  5. Supposed to be able to find it in a browser at Openspot.local/ (doesn't always work on my network)
  6. Mine has reset itself a couple of times. Poof. Reset. (I do run the beta firmware though)

So you'll notice my first con is that it is expensive. It runs about $230 on a good day. That's steep but $230 plus a $90 radio will allow you to talk to anyone in the world. Back in the day $320 would barely pay for your coax, and antenna. Forget about the transmitter, tower, etc. $300 is a bargain to open the whole world up to you.

One of my pro statements was that it has a built in operating system. All of the other hotspots (almost) are boards that connect to a computer of some sort (i.e. Raspberry Pi, Orange Pi Zero, etc). I'm going to say this in bold for emphasis. While some the other hotspots are considerably less expensive essentially the operating system on the hardware board (i.e. Raspberry Pi) must be installed and configured by the end user. The OS used is Linux. Also if you opt to use a Raspberry Pi Zero W you better know how to solder because the header pins don't come installed.

So yeah, you can save some money but you have to know Linux well enough to install the OS, ssh or VNC into the OS, configure the wifi, etc. Then you have to possibly hand configure system files to get your hotspot to actually connect to the network.

Me. I love Linux. Been using it since the late 90's and man do I love to solder. So let's tackle the Pros and Cons of another board, shall we?


The DVMega is a HAT device which sits atop a Raspberry Pi or other small board computer. It comes in a UHF only or VHF/UHF board. Cost is about $129 for the UHF only and $169 dollars for the VHF/UHF board. Now consider this. Get the dual board, add a $35 Raspberry Pi, and a $10 SD Card and you're rapidly approaching the cost of the SharkRF OpenSpot. And there is no attractive case either. Just the boards.

Add a Nextion screen and it costs more than an OpenSpot however having a Nextion screen displaying all the necessary information that you as a Ham operator want to see is worth the extra expense.

DVMega Pros:

  1. Cheaper than OpenSpot
  2. Can utilize wifi from the Raspberry Pi 3 or Pi Zero W board.
  3. Can easily be used as a portable device in the car or camper. Use your cellular data for hotspot.
  4. Uses Linux! Yes that is a Pro for guys like me. Can tweak under the hood.
  5. Can easily connect an exterior OLED or Nextion LCD display screen.
  6. Raspberry Pi uses SD card. You can make up cards with various OS's and MMDVM instances and pick your favorite.

DVMega Cons:

  1. Uses Linux (yeah I know that bullet was a Pro as well) If you know nothing about Linux it is a Con.
  2. To upgrade the firmware requires soldering and mad Linux skills with one method.
  3. To upgrade the firmware with another method requires additional hardware and the removal and replacement of the IC chip on the DVMega.
  4. No case. Must make or 3D print one.

The DVMega is a sweet little board. Firmware programming is weird and the easiest way to program it I've found is just to program the chip in an Arduino R3 Uno. There are several nice cases that can be 3D printed for it. My favorite OS to use with it is Pi-Star. And just above I talked about the ability to add an external screen to the device. Having a Raspberry Pi underneath the DVMega allows for this. With a FTDI controller and a properly programmed Nextion screen attached you get access to all kinds of cool information. This feature is the OpenSpot killer in my opinion.

Let's move on to the Zumspot. Right at this moment there is no real link for Zumspot. Zumspot sits ideally on top of a Raspberry Pi Zero W.

Time for the Pros and Cons:


  1. Small. Small. Small. Can be used on Raspberry Pi Zero W (or Pi3)
  2. Portable. Perfect for the vehicle or camper
  3. Does P25.
  4. Like the DVMega you install Linux on the Pi.
  5. Easy to add OLED or Nextion.
  6. Comparatively inexpensive compared to the others ($99).


  1. If you buy just the Zumspot board you'll have to solder header pins on the Pi Zero.
  2. Zumspot is UHF only.
  3. Zumspot seems to ship with original firmware. Mine came with 1.01 and is currently up to 1.13.
  4. Currently there is no "Official" Zumspot website. Got firmware off a message board.

If I had this all to do over again I'd just buy 2 Zumspots. I'd slap one on a Pi Zero W and put it in the truck armrest console (I'm doing this now) and the other one I'd build up in a big fancy enclosure with a Nextion screen on it. (I'm doing this now with a DVMega). But think of the money I'd have saved with 2 Pi Zero W's, two Zumspots, and 1 Nextion screen. The Zumspot currently does all the digital modes to include P25 whereas most of the others don't do P25. If you aren't scared of Linux and even better not scared of running Linux completely headless.........get a Zumspot. They are awesome.

And lastly you have to figure that if something works well the Chinese will copy it and sell it cheaper. Such is the case of the JumboSpot or as some call it, the ChinaSpot.

$45 gets you a Jumbospot on eBay. I have one on order but don't have it yet. I've heard the gamut on the internet from "These work great" to "they are complete crap". I'll add to this blog and let you know as soon as mine comes in. There are multiple sources on eBay. I found one that had a lot of sales of the Jumbospot with good Feedback. One assumes there are multiple sources copying and selling these. Probably some are better than others.

JumboSpot Pros:

  1. Cheap. If you get a good one and it works you end up dropping about $65 total for your entire setup. That's awesome.
  2. Very easy to add an OLED display.
  3. Alum high quality enclosures available for just a few dollars. Fits the added OLED display perfectly.

JumboSpot Cons:

  1. Expect that once you drop your $45 for one that that's it. Don't expect a warranty. Pay extra for all the Paypal and eBay protections if $45 is painful to lose for you.
  2. From China. You spend your money, you take your chances.
  3. Many users are removing the ceramic antenna (labeled AE1 in the drawing above) and reporting lower Bit Error Rates having done so.
  4. Some horror stories with firmware updates.

Received my JumboSpot and added an OLED and fancy case. What can I say? It works. It works fine. Nobody says "Your other hotspot SOUNDS BETTER" or anything like that. For the amount of money I paid and what I received I'm extremely happy.


SharkRF IP Connector Protocol Server

Here's a cool little trick that took me a bit to catch on to. I kept hearing about people buying 2 SharkRF OpenSpots (at $240 a piece) and doing something cool with them. Never quite caught on. Then one day I'm reading around the internet about OpenSpot and found out that SharkRF had created a Linux Server for SharkRF.

In the name of simplicity it works like this. You run the server, then connect to it. Then you give someone else with an OpenSpot your IP address and port that you are running the server on and they can also connect to it. The two of you are in a private talk group that no one else can hear because they aren't connected to the server. No one can hear. NSA and FBI proof (ha ha, probably not).

The server stats are viewable on a web page as well so you can see who you are talking to, etc. Thanks to W4EKG for helping out with the testing.

So, it's a bit geeky to install. Way geeky but really just a series of cut and paste commands. Start here at the Project Github page.

fire up a terminal on your linux machine. Yep, you need a linux machine. Clone the following 3 repositories

mkdir /var/sharkrf
cd /var/sharkrf
git clone
git clone
git clone

Then Compile.

cd srf-ip-conn-srv/build

SRF_IP_CONN_PATH=/var/sharkrf/srf-ip-conn JSMN_PATH=/var/sharkrf/jsmn ./

First you need to install Apache2 and PHP. Then configure it.

On his web page though he directs you to a web page to configure Apache2. When you open this page though it is a problem someone had. The solution however is further down the page. This was a head scratcher for me. Scroll down until you see this part. Don't do what the person who had the original post did. The screenshot below shows what you need to do.

Now go to this web page for configuring the server. Follow HIS directions. He did this. Not me.

So essentially you need to

- Follow the Github

- Install Apache2 and PHP

- Follow the directions I just posted above to configure Apache2

- Follow the directions on this page

I would have love to have cut and pasted his directions and added mine in but I think it is a little disingenuous to just cut and paste without attribution.

Once the server is working you can connect to it locally on your own network. Configure like this on the OpenSpot Connectors page. Obviously use your own IP address and whatever simplex frequency you want to use:

Now to let someone in internets land connect to your server you probably have to open some ports in your firewall or router. You will probably have to open port 65100. In the case of my server my ISP blocks servers on Port 80 so I moved my Apache2 instance over to port 90 and then went to my ISP configuration page and set an URL redirect up. So if you type (I'm making this up) in your browser it redirects you to and you never even know it. So in addition to opening port 65100 up I also had to open port 90 up. With your firewall just close them when you aren't actually using it. Security first.

Once connected both of you need to be on the same "Channel" you can use any pre-programmed talk group. It doesn't matter the folks on that talk group can't hear you, you are talking on a private server only.

Ok admittedly this install is a little tough. If you don't know much about Linux nor have ever configured Apache2 it might really suck and when you crack that code then you have to be a network guru to open ports and forward traffic to them, but the payoff in the end is pretty cool. Your own your own private Digital Radio Chatroom that only you can talk on. Got a buddy on ham you have long winded conversations with? Perfect place to move to once you connect on TAC 310 or something.