The $400 World Wide Mobile Me . . . Part 4: Frequently Asked Questions (FAQ)

∏This is Part 4 of a 4 Part Article.
Part 1 covers assembling the hardware

Part 2 covers provisioning the Raspberry Pi with Software

Part 3 covers Final Configuration of the hotspot

Part4 is Frequently Asked Questions

While I can’t be there to troubleshoot all your questions and problems as a community we can learn from each other.

Note: I am not going to be the general help desk for the Raspberry Pi, Raspian, or anything not directly connected to this article.  Try a Google or other search engine  to find your problem or error message, or go to stack exchange and ask them.   I reserve the right to ignore any questions that in my Opinion do not apply directly to this series how to!  Do not expect an email or call.   

If you have a problem, or a question in assembling this particular HOTSPOT send an email to:


 Frequently Asked Questions:

Q: I try using Pi Finder “Terminal” button, the screen opens up, and tells me that it can’t connect.  (Example: you get a message like, “Error: All configured authentication methods failed “)  What am I doing wrong?

A: You are having an SSH Access problem.  Check the following points:

  • Check your Pi Finder screen and make sure the SSH User ID is pi-star and the SSH Password is Raspberry  Note you should change it to something else, as someone can easily get in and use your system for nefarious purposes.
    • The easiest way to change the pi-star password is to wait until everything is done, and at the bottom of the configuration page you can change the password simply.
    •  If you want to change the password from the Raspberry Pi console enter the following commands:
      • sudo passwd pi-star
      • if this is the first time you have entered sudo you may be asked to enter the original password most likely raspberry
      • it will ask you to enter in the new password
      • it will ask you to re-enter the new password
      • if everything checks out it will inform you the password has been changed
      • do not forget to update the Pi-Finder screen with the new password!
  • The IP Address was used before with a different MAC Address or ID.  This can happen if you write new software onto the µSD Card.  On your computer (Not the Raspberry Pi) edit the file .ssh/known_hosts, find the previous IP address of the pi-star system and delete the line and save the file.  
    • On a MacOS or Linux System Open a terminal session and enter:
      • sudo nano ~/.ssh/known_hosts
      • scroll down to the pi-star previous IP address and delete the line
      • save the file
    • try accessing the Raspberry Pi with the Pi Finder Terminal button to see if it works now.
  • You skipped a step in the SD Card preparation.  SSH is disabled.  Starting in October 2016 the Raspberry Pi Foundation with the release of the new Pixel desktop shut off SSH.   They explain what they have done, and how to fix it here. Its a good lesson in Raspberry Pi Security.  To Summarize:
    • Power off the Raspberry Pi
    • Remove the µSD Card, and put it back in a card reader on your Laptop/Desktop
    • Open the drive volume:  boot
    • create a blank file called ssh in the /boot directory (i.e. /boot/ssh)
    • Note: there is no extension, if your editor created a file extension rename the file without one.
    • eject the drive
    • place the µSD Card back in the Raspberry Pi and boot it up.
    • SSH should now work

Q: I keep forgetting to type sudo before all the commands.  Isn’t there a simpler way?

A:  Yes, but it is a bit dangerous.  You could put the terminal session into administrator mode.  Understand that in UNIX like systems Administrative or root mode has very little protections and you can seriously damage you system.  For example, if you tell the system to delete a file(s) it will do so without question, including its own operating system essential files.  In other words, if you don’t watch what you are doing in this mode very carefully, you can brick the system.   If you want to easily enter root mode on the pi, simply type:

  • sudo bash

To exit root mode enter:

  • exit

another way is to enter:

  • su –

but that will require the root password.

Note: It’s probably a good thing to set the root password on the Raspberry Pi.  It is not set initially and most people never set it.  There are security considerations for this. If, however, you need to recover the disk drive during the boot sequence a program called fsck (the Linux version of ScanDisk) will ask for it.  If you have not set a root password, you will not be able to proceed further and the only alternative is to re-write the µSD card with the last backup.  Essentially you have a brick on your hands.  For this reason I always set the root password and to something very secure.  Please note that the error I have just described would not be visible as we have configured the DHAP as a headless system.  To detect this error, you would need a monitor with HDMI input and a USB keyboard connected to the DHAP.  I have such a setup at home, I just don’t take it traveling with me.  The Raspberry Pi being so  small and simple tends to make people thing it is not complex.  Hook a HDMI monitor to the Raspberry Pi and watch the boot sequence, it is pretty complex, all the programs running in the background.  But I digress…

To set the root password enter:

  • sudo bash
  • passwd root
  • set the password
  • exit
  • you should return to a pi-star prompt


= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

This concludes the 4 Part Series The $400 World Wide Mobile Me….


Happy communicationg, and having fun with your new Hotspot!


Barry, K0BSB

The $400 World Wide Mobile Me . . . Part 3: Configure the HotSpot

This is Part 3 of a 4 Part Article.
Part 1 covers assembling the hardware

Part 2 covers provisioning the Raspberry Pi with Software

Part 3 covers Final Configuration of the hotspot

Part4 is Frequently Asked Questions

Set up your Hot Spot

Everything if it has gone well is setup and should be running.  To make sure that the system and software is initialized and synchronized at this point you should reboot the system.    If you are using a Raspberry Pi Model 1 (any variant) instead it’s best to install the WiFi dongle.      Model 1’s had only two USB ports rather than 4.  The Model 1’s did not have as well designed power supply as the model 2, 3, or Zero, and so every time you put a device on the USB Bus it caused a power drop in the main supply bus which would cause the Model 1 to reboot.  If you just pull the power on any Raspberry Pi it may cause a glitch during a file I/O and the OS is writing to the files any time it needs to, so you may not be aware.  Pulling power abruptly may damage your µSD Card (Remember that is the Pi’s Disk Drive).  While all it takes is to rewrite it again, you will lose any work between the last backup of the card.

The safest way is to shutdown the Model 1’s before putting any device on its USB Bus.   This is best done as follows from the SSH console on your Laptop/Desktop:

  • sudo shutdown -h

If you are using a model 2 or a model Zero without WiFi, now is a good time to put in your WiFi Dongle.

If you are using a Model 2, 3, or Zero, from your SSH console on your Laptop/Desktop enter:

  • sudo reboot

When the system reboots, this may take anywhere from 30-40 seconds to 2 minutes, go grab a cup of coffee and relax, we have done the hard parts.  If you can’t wait watch the green activity light on the circuit board, not the RJ-45 Connector, when it stops flashing vigorously the system is mostly booted.  The Pi Finder screen on your Laptop/Desktop should have reset to this:

No need to open an terminal session, but you can if you want, just incase you have some tweaking to do.  When the terminal window opens with the command prompt the system is booted.  Or you can close the Pi Finder window it’s your choice.

Make sure the system you are now running on is still on the same network as the Raspberry Pi.   Then open a browser and enter:

  • http://pi-star.local/admin

If a window opens go to the Configure the Pi-Star Hotspot Section.  Otherwise:

If you get a server not found, or other error, you may not have the Bonjour software active on your the system you are trying to access the Raspberry Pi with.

On a windows machine, you can download Bonjour & Quicktime (Apple Computer’s system locator, MP4 Video Player) from for free from Apple.

A MacOS machine should have it already installed, IOS has had software functions since IOS 4.0, and Android since JellyBean 4.1, however, they may not be active.   If that is the case a free app called Fing is available on both IOS and Google Play that will implement the nmap scan function and reveal the IP address of the pi-star server.  Then you can access it as described with Angry IP Scanner below.

If you are on a Linux Machine it can be loaded with:

  • sudo apt-get install avahidaemon netatalk -y

It was already installed on the Raspberry Pi when you pushed the Bootstrap Button. If you don’t want to install this software on your thin client machine, (makes life a bit easier, but not required) you will need to know the IP address of your pi-star server.  A highly recommended utility for your Laptop/Desktop is a freeware graphical nmap derivative called Angry IP Scanner which will scan the local network you are on and report the IP Address of all devices it finds on the network.  This can be very useful in trouble shooting your network.    As mentioned above a similar piece of software called Fing will run on mobile devices.  After you have determined the IP Address of the Pi-Star Server (computer) enter:

  • http://<ipaddress>/admin   Example:


Configure the Pi-Star HotSpot

The default user name:  pi-star

The default password:    raspberry

If you changed either of the above substitute your user name/password. After you have hit return on the local web address of the hotspot, the browser indicator will spin/flash for a short while, and then a window will open stating No Mode defined.  If you don’t see that you have some sort of network problem, or the web server is not running.  Ensure that both the system running the web browser and the Raspberry Pi are on the same network.   If they are you may try rebooting the Raspberry Pi.  If that still fails, there are so many possibilities, I can only reference you to the pi-star support pages located  on Facebook and the Wiki.  Failing that recheck the steps to this point to ensure you encountered no errors getting here.  I will continue assuming everything is fine and your browser opens to the page shown below.


After 10 seconds or so, you will see the a page asking you to sign in.  Use the appropriate username and password.  After they are entered, the initial configuration page will open

At the top of the page is the Pi-Star Banner, the broad red stripe.  In the lower right corner of the banner are links to various functions in the program.

Select “Configuration”and the following page will open:

Begin configuring your hotspot  Your choices may vary from the items below.  It’s your HotSpot and your choices:

  • Select MMDVMHost
  • Select Simplex Mode
  • Under MMDVMHost Configuration Select the modes you want to run. I was advised not to select more than two, since the processing of packets can get a little jittery if you select more.   However YMMV (Your mileage may vary).  I selected DMR & D-Star.
  • I have not created a display yet so select None
  • Set Hangtime to 20 Sec
  • For your URL set:<URCALL> & Auto
  • Fill in your personal information
  • continue on….. Some of the previous information not shown for privacy considerations but you shouldn’t need help there.
  • The Radio Modem type is either
    • DV-Mega Raspberry PI Hat (GPIO) — Dual Band
    • Or Single band —- what you are using

Page down (Most likely the form does not all fit on the screen)

  • I set the DMR Master to 3102
  • color code is 1
  • and DMR DumpTAData on
  • My D-STAR Configuration is as above (REF053A is MN Statewide on D-STAR) You could select Manual and switch to where you want to go.
  • I set Dasboard Access to Public all the rest to private
  • Select Apply Changes (any of the buttons on the page will save configuration information you have entered so far and you will see:

Now we need to set up the WiFi Connection.

  • Make sure you are on the Configuration Page.
  • Turn on your portable WiFi HotSpot or Dongle, make sure it is hooked to the internet.
  • make sure that the WiFi Dongle is attached or the Pi3’s WiFi is active
  • On the banner, of the Configuration Page is a selection marked “Power”, select it
  • a new screen will open giving you the choice of “shutdown” or “restart”
  • select “restart”.
  • After the Pi Boots again (between 40 sec and 2 minutes)
  • the system should automatically go to the Dashboard Page
    • If it doesn’t type into your browser http://pi-star.local/admin or its ip address as before
  • after you most likely will not have to sign in
    • If the sign in window appears do so
  • select Configuration from the Banner Menu
  • page down on the Configuration page to the “Wireless Configuration Section”
  • select the Configure WiFi Button
  • The screen will open up and you can select “Scan for Networks”
  • The system will scan and output identifiable Networks
  • select the one that you will use in portable operation.
  • highlight it, and choose save and connect.
  • Go back to the top of the screen and select “Power” and then “Shutdown”.
  • switch the DHAP Off
    • This is how you should turn power off Shutdown
    • then Power Off
    • Just switching the unit off may destroy your µSD Card
  • If you have charged up the 18650 batteries and installed them disconnect the external power
  • unplug the ethernet connection
  • switch the browser you plan to use to the portable internet connection you plan to use
  • Switch the unit on
  • After about 40 sec to 2 minutes, log into the system again if required
  • If you see the Admin or Dashboard Screen set your DMR Radio to the Shark Zone and select a frequency.
  • Try it out — if it works your done!
  • Again, I assume everything is working so we are done.
  • Select admin or dashboard and you should be good to go….

. . .  I am… Are You?



Continue to Part 4: Configuring the MMDVMHost Software Click Here


The $400 World Wide Mobile Me . . . Part 2: Provisioning the RasPi

This is Part 2 of a 4 Part Article.
Part 1 covers assembling the hardware

Part 2 covers provisioning the Raspberry Pi with Software

Part 3 covers Final Configuration of the hotspot

Part4 is Frequently Asked Questions


Getting Started

Now that we have assembled the hardware parts necessary, it’s time to assemble the physical package.   Next we have to load the software to run the Pi.   I am not covering  in detail physical assembly of the Mini DHAP.   For the most part Hardened Power Systems (HPS) puts together the DHAP , and you only have  to mount the circuit boards, and batteries.   If you need assistance with your purchase Bill at HPS (931) 207-0079 has always been helpful, knowledgeable, and given good support.

When you are mounting the circuit boards HPS provides Stainless Hex Head Screws to mount them.  Bill prefers them since it is much harder to strip the heads out.   To assemble the DHAP you will need a 1/16th in Hex Key.  Use proper techniques when handling the Raspberry Pi and DVMega Boards, so as not to impart a static charge and ruin the solid state components.  Also watch tightening the screws that hold the boards in place, its only ABS Plastic, so as not to strip out the built in standoffs.

Lastly, pay close attention to mounting the DVMega onto the stake pins of the Raspberry Pi.     The pins are easily bent, and straightening them out can result in breaking them off.  Also watch alignment of the female header of the DVMega Board.  It should attach to both rows starting at pin 1.   I have seen a few people shift it down one pin placing the header starting on pins 3 & 4 instead of pins 1 & 2.  It’s best to review the installation PDF published here before continuing.  Note: If using the DHAP & RasPi2 or RasPi3 you will not need to glue a stand off to the board, HPS provides a  mounting bracket.

The Raspberry Pi has anywhere from 256 MegaBytes to 1 Gigabyte of on board memory, but uses the SD card as its solid state disk drive.  The older Raspberry Pi model 1, uses the Full size SD card while the Raspberry Pi Model 2 and later use µSD cards.   The form factors are different, and the Mini DHAP requires the Model 2 or 3.  You still can use a DV Mega card with the Model 1, just not the DHAP case, so this article will also cover setting up that configuration, but Power, Packaging, and Cooling (PP&C) are left as an exercise to the student.

In fact, If you want to create an even smaller package the Raspberry Pi Zero, or better yet the Raspberry Pi Zero with WiFi should also work well.  These are actually single core versions of the latest four core Raspberry Pi3. I have thought about trying to create a version of the Pi-Star with a DVMega and a WiFi Pi Zero.  Again PP&C are left as an exercise for the student.

This variant may only require two 18650’s as the Pi 2 board draws about 500 mA, the Pi 3 Draws about 700 mA, and the Pi Zero with WiFi draws about 120 mA at 5V.  I would also suggest you add a Buck Converter to the power circuit if you intend to build one so you will need to provide 6.2 VDC to power the 5V Raspberry Pi’s.  Note the Buck converters will generally handle 6-36VDC and give you a reliable, steady 5VDC output up to about 3A.  Also you will need to put stake pins on the Pi Zero for GPIO bus, to mount the DVMega.

I will reiterate this further in the article, but most SD & µSD cards can be read an infinite number of times.  However, any one memory location can only be written about 100,000 times before data loss will occur.  Since the Pi’s use this type of memory as its disk drive you can count on them failing and the Raspberry Pi to act like it has suffered a disk failure.  It’s really no big deal, since all you have to do is rewrite the same software onto the same card and you are back in business again.   You can go through all the steps in this article, or simply read the completed file back into your computer as an .IMG file and not have to generate the software again.   The .IMG file will generally be the size of the SD Card, so rather than take up the space on your disk, you may want to copy the .IMG file to a USB Thumbdrive for backup purposes.

I always said my friend Murphy was an optimist, so if the card is going to fail, it will do so in the field when you don’t have a laptop with you!  To cover that eventuality I carry a second duplicate µSD card in it’s SD Carrier in keep it inside the DHAP case for an “in the field” backup.  Also the Raspberry Pi 2’s have a spring powered eject for the µSD Cards.  I have seen cases where they get bumped while the PI is powered up, and this can cause the data on the card to be ruined and need to be re-written again.

So with that caveat mentioned let’s generate an operating Raspberry Pi System.

Prep the Memory Card

For a multimode radio hotspot we will generate a Thin Client (Lite) version of MMDVMHost.  A thin client uses a web server to control the hotspot, and only needs a web browser as the user or client terminal to access the hotspot.  Thus, I can use my laptop, tablet, or phone for a screen, in fact,  anything with a web browser.

Note: If you do not have your DHAP Assembled yet, or you are not planning on using one, you can still proceed with generating the system with a µSD Flash card, and a bare Raspberry Pi Board with or without the DVMega Board.  If you don’t have a case for the Pi just be careful as not to cause any shorts until you can protect the bare board.

The computer you use to generate the code for the hot-spot can use any OS, however I use my Apple MacBook Retina (2016) and MacOS Sierra.  However, you can use a Windows Machine (XP, Vista, Win7, Win8, or Win10), or Linux to generate the µSD Card.  That said ,you can actually use a Raspberry Pi to generate the software for the hotspot to run on a raspberry pi, since the Raspberry Pi runs on a version of Linux.

The Computer is used to download the software onto the µSD card, and then prep the RasPi for use using SSH, so not much software is required on the prep machine.  The Find My Pi Software referenced here will provide an SSH terminal for MacOS, Windows, and Linux users.  However the initial setup process will vary depending what operating system you use.    If you are using Windows or Linux, this article will assist you for the most part, but some specifics will be different.  For those operating systems, there are plenty of articles on the Web to more than cover the slight differences if you get stuck.  Just ask your favorite search engine for help.

Note: you will need a desktop or Laptop for this step, most tablet computers cannot do the µSD Card Prep.  Once Pi-Star is running you can use a tablet or phone to configure it.

  • Download the AdaFruit Raspberry Pi Finder Document[1] and Software[2] as outlined in the documentation for your Operating System, and install the Pi Finder for your operating system on your computer.
  • For MacOS Users: Transferring the Pi Software to the µSD card used to be a real pain, until I found a Great MacOS program called Apple Pi Baker[3] by Hans at Tweaking4All.  For free software he offers incredible support.  He also makes some other great utilities, so you may want to surf his site for other MacOS Utilities.  Scroll down to the most recent version section to get the download[4] (v1.9.2 at the time of this writing)
  • First download Pi-Star onto your computer[5] from MW0MWZ’s site.  You can also use the MMDVMHost Application or Blue DV Application consult the BrandMeister DVMega Page[6] for information.  Setting the latter applications up on your Pi is “… an exercise left to the student.”
  • Pick the latest version zip file for the Raspberry Pi.
    • I am using in this article
    • UnZip the file, if necessary (MacOS does this Automatically) and note where the unzipped file is stored.
  • If you are not using MacOS follow the instructions for the Windows or Linux Imaging Guide below the downloads section on the MW0MWZ site, and then go to the setup your Raspberry Pi section below.
  • If you are using MacOS
    • write the Pi-Star Image onto the µSD card you are using, with Apple Pi Baker
    • Download Apple Pi Baker DMG file on to you system.
      • Right click the file, and select open button (Tweaking 4 All is not a Registered Apple Developer, but his software is safe)
      • Close the software, mount your µSD Card and restart Apple Pi Baker.
      • Enter your administrator’s password
      • Highlight the µSD card  in the drives area, If you don’t see the µSD card mounted, click the small refresh button on the upper right hand corner of the box.  Select the µSD card, you want to write to.  (Make sure you select the correct “disk” or you could nuke your MacOS Disk! — Check the size it would be a µSD Card size like 8 or 16 GB NOT 128/256 GB disk size!)
      • select the Prep for NOOBS button this will reformat your µSD card for the Pi.  Again make sure the correct “disk” is selected, there is no turning back after you select Prep for NOOBS.
      • After the card is formatted properly according to SD Foundation Standards.
      • On the right side of the Window (Pi ingredients box) is a small button with three dots, select it.
        • A window will open to select the .img file you will write to the µSD card.
        • Navigate to where the unzipped pi-star image is on your system and select it.
        • Then select Restore Backup
        • When ApplePi Baker finishes writing your µSD card it will eject the card. Remove it from your system

Set up your Raspberry Pi

You may need a couple of cables temporarily for the next steps. An Ethernet cable, and a USB to µUSB to power the Pi (5VDC), or service power (117VAC) to 6-36 VDC with a 5mm x 2.1 mm Coaxial power connector.

A note about the Find My Pi Software.  There is nothing magic about this software, it just makes the job of setting up the Pi so much easier.  Prior to this software there was a long chain of software loads, that this does automatically.   Additionally it will put a couple of additional programs on your Pi.   It loads some development software, which may be useful in the future if you want to add some additional functions such as a display, or searching logs, etc.  It loads a piece of software originally developed by Apple, called Bonjour, that allows you to access your Pi by <computer name>.local as opposed to having to find it by IP address.   It loads a some software originally developed by Microsoft, called SAMBA, that allows you to access the Pi’s Disk drive from another computer on the network as a network mounted drive.

Lastly it loads a piece of software developed by AdaFruit Company called Occidentalis.   The name Occidentalis is a variety of a black raspberry.   The software uses a file on the boot partition (occidentalis.txt) that contains the host name, the WiFi SSID, and the WiFi Password, and sets them up when the Raspberry Pi is booted.  A disk that the Raspberry Pi uses is partitioned into two formats.   A linux format, and the boot partition which is written in the FAT format.  A FAT formatted drive is readable by almost any computer (Most Thumb drives use this format.)  While putting SSID and it’s password in an unsecured text file on the disk is a major breach of security it is convenient for headless versions of the Pi, as it allows easy switching of the WiFi (at Home, In your Mobile, Your cell phone or other mobile hotspot, or the local coffee shop) depending on operating location.   If you want to remove this security flaw, a simple one line command will remove it.   It’s documented below, and it’s use is optional as to the user’s preference.

  • Make sure that your Pi is powered off. Inserting or Removing the µSD card (The Pi’s Disk Drive with power on may destroy the data on it.)
    • Note: µSD cards are only good for about 100,000 writes. They can be read an infinite number of times, but writes will eventually cause the card to be unreadable.  At the end of this process we will make a backup to carry in the DHAP case.  Just in case! 🙂
  • before you remove the µSD card from your computer find it mounted on you computer.    You may need to mount it, but you will see only a small drive mounted called “boot”.  Before placing this SD Card into the Raspberry Pi you need to create a file called “ssh” with no extension, or quotes.
    • On a Mac or linux machine simply open a terminal window and type the following command
      • sudo touch /Volumes/boot/ssh
    • On a Windows machine just mount the drive and use a text editor to create an empty file.  You may have to rename the file to remove an extension from the editor.
    • Then eject the drive and continue
  • Put the prepared µSD card with Pi-Star on it into the rear Memory card slot. It will only fit one way (The gold fingers should be up).  I am using an 8GB µSD card which is big enough for this function. Use more or less as you see fit, but at least 4GB.
  • Connect the Ethernet cable to the RJ45 Jack on the Pi and the other end to an empty RJ45 Jack on your internet router. We will be doing a lot of downloading on the Pi setting it up, and this is the easiest way.  If you have to remove a device from the router because you have all the jacks used, this will be temporary for about an hour or so.
  • If you choose not to use the ethernet connection, you can set up the Raspberry Pi to connect to WiFi on boot.  However, it takes a lot of extra steps to connect a cold Raspberry Pi to WiFi and the process is not straight forward.   Fortunately, it is well documented on the web, but you will need to have a keyboard, and a monitor most likely with an HDMI input.
  • Connect µUSB connector to the RasPi (left side as you look at the front, or the 117VAC DHAP Adaptor to power the PI.  You could also use the 18650 LiON Batteries to power the Pi just make sure they are fully charged.
  • If using the DHAP turn the power switch on.
  • The rear Red led will go on, and the rear Green led will flash. wait until the Pi RJ45 connector shows both Yellow and Green leds.  It’s okay if the green is flashing, but wait until the rear green light somewhat quiesses.
  • Go to the Find my Pi application you down loaded earlier, and open the program. You will see the image below.

  • Push the Find My Pi Button when the program opens.
  • When the program finds a Raspberry Pi, the Main screen will open.
  • select the ip address of the pi from the pull down on the first line. If you have only one Pi on your network it will select it for you.
  • Enter pi-star for the user id, and raspberry for the password.
  • select Terminal, a SSH terminal should open for you on your computer’s screen.
  • If you get an authentication error, check that the correct ip address is selected and pi-star is the user-id, and that you created the ssh file on the boot partition
  • You should see a screen somewhat like below:

  • Enter the following commands at the command prompt.
    • pi-star@pi-star(ro):~$ rpi-rw                  <==Change to Read Write mode
    • pi-star@pi-star(rw):~$ sudo bash           <==SU to root mode
    • root@pi-star(rw):pi-star# df -h               <==See Disk Size — 1.7G on an 8G drive

Filesystem      Size  Used Avail Use% Mounted on

/dev/root       1.7G  1.2G  389M  76% /

devtmpfs        481M     0  481M   0% /dev

(extraneous display deleted)

  • If /dev/root size is approximately equal to µSD card size skip to Bootstrap Section, otherwise we need to resize the disk partition.
    • root@pi-star(rw):pi-star# resize2fs /dev/mmcblk0p2

resize2fs 1.43.3 (04-Sep-2016)

Filesystem at /dev/mmcblk0p2 is mounted on /; on-line resizing required

old_desc_blocks = 1, new_desc_blocks = 1

The filesystem on /dev/mmcblk0p2 is now 1892608 (4k) blocks long.

  • root@pi-star(rw):pi-star# df -h

Filesystem      Size  Used Avail Use% Mounted on

/dev/root       7.1G  1.3G  5.6G  19% /

devtmpfs        481M     0  481M   0% /dev

(extraneous display deleted)

  • reboot (wait a few moments and the Main Screen will reopen)
  • We will be installing some helper programs which will make the hotspot easier to use. If you see something you don’t like you can remove it by entering

sudo apt-get remove <program> at the command prompt

  • One of the programs we will add is called Occidentalis, a program that on boot will setup your WiFi to the RasPi for you. It uses a file in the /boot partition of the µSD card which is formatted as a FAT32 partition.  This means that you can access this partition with your laptop/desktop and edit the file on that machine to change wifi access points easily.   The text file to edit is called occidentalis.txt, and is explained in the Find My Pi documentation you downloaded.
  • Set up the Occidentalis defaults:
    • Enter pi-star for the hostname
    • Enter <Your WiFi SSID>
  • Enter <Your WiFi Password>
  • select the terminal button
    • at the command prompt enter rpi-rw to put the disk in write mode
    • close the terminal window
    • Now select the Bootstrap Button
      • this will take a few minutes while software is being loaded on your pi.
      • it will also update the software library catalog and update the software to latest released versions
    • select the terminal button again to get an open ssh screen
  • This is the potential security breach I mentioned at the start of the article.  If you want to seal it (I find the convenience factor worth the limited risk personally).  You may want to let Occidentalis set your system up to use a specific WiFi and identify itself by host name (I use K0BSB_Pi-Star) and then allow the system to be installed and run through at least one reboot.  After it has set everything up, then remove the software and .txt file.  as shown below:
    • At the command prompt enter:
      • sudo apt-get remove occi -y
      • sudo rm -f /boot/occidentalis.txt
    • this will effectively remove occidentalis from your system.
  • because of the way that pi-star sets things up we need to re-run some installs at the command prompt enter
    • sudo apt-get install -y node hfsprogs
  • Samba is installed to allow you when your pi connected to your network to see it as a remote disk and transfer files easily without having to use thumb drives or other means.
  • now restart Samba by entering sudo /etc/init.d/samba restart
  • You may be done now, or maybe not!
    • If you have a Raspberry Pi B, B+, or Raspberry Pi 2 Running Raspian Wheezy you do not have to repoint or disable the Bluetooth.
    • If you are running Raspian Jessie  on the above hardware perform the steps below to ensure the GPIO Serial Port is enabled
    • If you are running an older version of the DVMega Pi Hats, and they are running firmware 3.07 or earlier you will need to flash the latest firmware (3.14 and it is stable at the time of this writing) to the cards.  Note: this will void your warranty, and I take no responsibility for the results you get.  But Hey! It won’t work anyways so what have you got to lose.   I think you can send the cards back to Guus van Dooren ( ) read about it here
      • If you have the single band DVMega you can:
        • remove the Arduino UNO from the board, and Flash it using a Arduino Development kit as described in this YouTube Video
      • If you have the dual band radio, or want to future proof either radio to allow easy flashing of the DVMega directly on the Pi, you are not done yet.  Continue on.
  • If you are using a Raspberry Pi3 you need to disable or repoint the Bluetooth software.  This may be already done in the software you are using, Verify that these changes are made.
    • For those that want to understand what’s going on
    • For those that want to just get on with it perform the following:
      • First enable the GPIO Serial Port
        • sudo nano /boot/config.txt
        • add the following to the end of the file:
          • enable_uart=1

Prep the Pi to Flash the DVMega Firmware (Optional)

Update the DVMega Firmware (Optional if Greater than 3.07)   You can find an article to set your Pi up to flash the DVMega Firmware by adding a wire to the board.  Note: this will void your DVMega Warranty so solder carefully!   It’s documented here:

HOW-TO Update DVMega firmware without a programmer or an Arduino

After you have made the hardware changes the following steps will setup the pi to update the firmware, and then actually do it.

  • Ensure you can update DVMega Firmware loading the following systems software
    • sudo apt-get install git avrdude python-dev python-rpi.gpio
    • git clone
    • cd avrdude-rpi
    • sudo cp autoreset /usr/bin
    • sudo cp avrdude-autoreset /usr/bin
    • sudo mv /usr/bin/avrdude /usr/bin/avrdude-original
    • sudo ln -s /usr/bin/avrdude-autoreset /usr/bin/avrdude
  • Update the operating software and Firmware of your Raspi and clean up the queues
    • cd
    • sudo apt-get install rpi-update
    • sudo apt-get upgrade -y && sudo apt-get dist-upgrade -y
    • sudo apt-get autoremove -y
    • sudo rpi-update
  • sudo reboot
  • when the system reboots, you should be able to see the pi-star system on your shared network drives. You can copy the DVMega Firmware updates over this way as well.
  • Update the DVMega with the latest firmware it needs it (Must be 3.07 or later) with the wire mod installed

Flash the DVMega Firmware (If older then 3.07)

Your Raspberry Pi system is now generated.  Now would be a good time to power off the Pi, remove the SD Card and copy the system as an .IMG File using what ever Software you used to create the SD card in the first place.  If you capture the image of the card, it will be the size of the card.  This will be a lot of wasted space, since the actual disk used is between 2 and 4 GB.  I recommend use a thumb drive to hold the image rather than your disk drive.  Now is also a good time to copy that image on the second SD card you may have purchased as a backup incase the operating card gets clobbered/over written too many times.


The next section will cover the setup of the MMDVMHost for radio operation.  We are almost there, and the next steps are easy.

Continue to Part 3: Configuring the MMDVMHost Software Click Here


Barry, K0BSB

Links Below to help you find software:

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The $400 World Wide Mobile Me . . . (Part 1)

This is Part 1 of a 4 Part Article.
Part 1 covers assembling the hardware

Part 2 covers provisioning the Raspberry Pi with Software

Part 3 covers Final Configuration of the hotspot

Part4 is Frequently Asked Questions


A fully equipped Mini-Mega for about $300 and a DMR HT Radio for about $100 and you are ready, set, GO…

by Barry, K0BSB

A very portable mobile rig capable of working the world, and very transportable, Even through TSA.  If they object show them the LiON Batteries which you can’t pack.  It’s worked for me.  


I like taking my ham radio with me wherever I travel, by plane, train, or driving.  I love letting the civilians marvel at the ease of making contacts halfway around the world, or even several hundred miles away with a nice clear signal.  Have them chat with someone settling down for an after dinner drink in England, or chatting with someone fishing off the pier in Australia.  I just hand them the speaker mike and let them go, after all I am still the control operator with my HT firmly in my grip.  Note: If you operate outside the US be sure to register with the country whose boarders you are operating in, including the nation of registry of the cruise ship you are operating from, and get the captain’s permission as well.  It’s a great recruiting tool for Amateur Radio.

This is the Mini-DHAP opened so you can see its innards:

Here is the Mini-DHAP in travel operating mode for both DMR and D-Star.  Not shown is my Cell Phone which I use as the Hotspot and as a console for the Mini-DHAP running web based Pi-Star.

This is a Shark OpenSpot setup in Operating Travel Mode, a Brief case rather than a Grab ‘n Go.

So why this stuff rather than using the Shark RF Open Spot.  The cost is about the same.   Well I find it more flexible, if you have some parts laying around, like an older Raspberry Pi you can put it back to work.  Also the Mini DHAP is a much smaller package by the time you add power, Wifi, and other stuff.  Also, you may need to bring a laptop to change configuration in the field, I can use my phone for the MiniMega DHAP.

Packing a lot of gear, like I was going on a DXpedition is not my idea of fun though.  Besides the comments I get from the XYL about why I need that all that Junk, especially when I remind her that luggage is generally restricted to about 50 pounds.

Packing my Toys for travel, I am down to:

  • a DMR/DSTAR Hotspot that is 4”x4”x2” weighing 14 Ounces with batteries.
  • My TYT MD-2017 (DMR) and/or ID-51A (D-STAR)  HT(s) with speaker mike(s).
  • My phone as a terminal and/or My Jetpack Hotspot, incase I want to save my phone batteries

If I want to operate for more than a day add:

  • a 1.5”x5.5”x4” battery charger.
  • 12VDC adapter with 5.5 x 2.1 mm Coaxial DC Connector for the HT & Battery Charger
  • HT Charging stand
  • 2 small square Apple style wall wart AC Adaptors, or a small 6 outlet USB power with a USB3 socket to charge my laptop that uses either a 117VAC USA power cord, or a 220V EURO Power cord.
  • 2 flat 6,000 mAh power banks[1] for our two phones and jetpack, my noise cancelling bluetooth headphones (especially if I am flying) for listening to tunes or movies.

The whole thing fits in a trim cross body messenger bag with my Laptop, or a side pocket in my DSLR camera bag.  No Muss, No Fuss!  My only outside dependency is either a WiFi Connection, or a Good LTE hotspot connection to the internet is available.

Initial Parts Shopping

You can get many of parts from GigaParts including the Raspberry Pi, the DV Mega, Memory card, and Hardened Power Case.  It’s more expensive that way, but you will get all the pieces together shipped to you.  However the cost will be about $370, slightly more than the price of the basic SharkRF OpenSpot, but you still have to add the cost of WiFi, an internet source, power etc.

However if you purchase the pieces from various vendors you can save some dollars and a bit of hassle (read that as: get out the soldering iron!).  I have included a lot of links to Amazon, It’s where I got a lot of my stuff, however that is not the only source, and the least expensive price.  Prices and availability were at the time I wrote the article, YMMV.

  • You will need a Raspberry Pi (RasPi) a credit card sized Single Board Computer, you can use any version as long as its at least the model B if you already have one laying around. If you are purchasing one, Think about the Raspberry Pi 3 Model B+, as it has WiFi and Bluetooth on the card. but you will need to disable the Bluetooth or repoint it in the setup.  It’s well documented on the here.    Note: I use Amazon Prime a lot.  You may want to consolidate the Amazon Orders to save on shipping.  I get my Raspberry Pi’s at MicroCenter in St Louis Park[2], they have convenient hours, and they are local.  They sell the Raspberry Pi for $29.99.
  • MicroCenter also sell their own branded class 10 memory cards cheap $7 or $8 for either 8 or 16 Gigabyte (GB) µSD cards respectively.  Ask for them at the register, when you checkout.  I recommend you buy at least two cards (one for backup, more on this later).  You only need 4GB for the software we are using so 8 or 16 GB is plenty.  However, 32 or 64 will let you use the Pi for other functions when not using it as a hotspot, and they are also pretty cheap.  Also you may want to buy an 8 or 16 GB USB Thumb Drive at the same time to save a backup copy and not take up that space on your hard drive as well.
  • Order the DVMega Card[3] direct from Gus in the Netherlands (or Eric Osterberg, N0NKI– Locally his prices may vary) the Single Band UHF only for €99 / US $117) or the €135 / US $159 Dual Band UHF/VHF[4].  Be sure when ordering to check the add wire option, or you will have to do some not fun soldering.  The wire allows you to flash the firmware on the DVMega Board directly from the Raspberry Pi.  It’s only one wire but the board is crowded, and you need to be careful.  I did mine, but I had to get some reader glasses about 1.0 Diopter larger than I need to read.
  • The Case, a DHAP Mini Mega, can be ordered from Hardened Power Systems (HPS)[5] for $99.  The Coaxial 5mm External power plug disconnects the batteries from the rig when plugged in, so you can run with external power without lighting the Lithium Ion 18650 batteries on fire.
  • You will need a few more items for the complete setup:
    • An sma antenna[6]. I use a Maldol MH-209 SMA antenna but it is expensive about $30. However, Amazon sells a Retevis RT20 dual band stubby which is compatible with the BOAFENG BF-UV3R, Yaesu VX-1R, TYT  TH-UV8R, or the WOUXUN KG-UV6D for about $12.  If you have an extra stubby antenna that will fit the above radios you can save some bucks.  Optionally a 90 degree SMA connector, however, finding one is an exercise left to the student.  I ordered some from Amazon, but watch the sex of the connectors and pins.   I ended up ordering another whole set because the connecting pins were the wrong sex.
    • Battery Charger[7]. LiON Batteries have to be charged carefully and properly or they can catch fire.  You need a proper charger, one available at Amazon is $32. One positive is the 12V power adapter can be used to power the DHAP.  You may want to get a plastic case for them as well since if the short they can cause a fire as well — i.e. the case of the Samsung 8 Cell phone.
    • 2 or 4 Lithium Ion (LiON) 18650 batteries.[8]  It’s your choice the Mini DHAP will hold 4, required is two in series to get 6.8VDC or more. Four simply connects two series pairs in parallel for greater operating time.  There is a link on Hardened Power Systems’ MiniMega Page at the bottom to Amazon to order the batteries.  The ones he shows are the correct size for the enclosure and are reliable.  I strongly recommend you order these, as 18650 LiON Batteries vary in size and top profiles, and may not fit in the case or the contacts.  These will definitely fit the DHAP enclosure, and should give 8 to 10 Hours of operating time.  A Four pack of 18650 batteries runs $18.99.  LiOn Batteries can be dangerous!  Do not dispose of them in the Trash, use a safe and environmentally safe disposal method.
    • A 117VAC adapter[9] to run the DHAP can be purchased for about $8, a useful but not a required accessory. Also, any power source with a 5mm coaxial plug that delivers between 9 and 36 VDC will work, if you have an old laptop brick laying around that will work.
    • Having an adapter cable with Anderson Power Poles on one end and a 5 mm x 2.1 Coaxial connector is handy as well[10] for about $1
    • A 12VDC Plug also known as a cigarette lighter adapter on one end, with a 5 x 2.1 coaxial adapter on the other allows you to run the DHAP mobile without using its batteries.

If you have to purchase everything the total is about $305 complete for all the parts, including Batteries and chargers, portable 12V power, antenna, and $316 with optional Power Pole Cable.  You may not want some of the accessories, or have stuff laying around in your junk drawer which will save additional funds.

Note: I had older DVMega which needed the firmware updates to work with Brandmeister instead of just D-STAR.  To upload the firmware into the DVMega requires an extra step, and a patch to the DVMega Board adding a wire from the Flash Memory Write enable to an unused GPIO pin (GPIO4 pin 7 of the RPI Bus).  If you order the DVMega from the link provided they will solder the wire to the board for you if you check the option box (at no additional cost).

Continue to Part 2: Programming the Raspberry Pi Click Here


Barry, K0BSB

Links Below to help you find parts:

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[1] I use this $18.99 @ Amazon

but this one by PowerJuice has captured my interest for $19.99










Breakfast Time again – August 26th 2017

Hello from your host’s Dave – KE0NA and John KA0KMJ

It’s been another two weeks, so it’s time to get together at Fat Nat’s Eggs in St. Anthony Village for DMR breakfast!

Enjoy some delicious food, get your DMR questions answered, arrange to have a code plug loaded onto your radio.

It’s the best way to catch up on the dynamic world of DMR in Minnesota while socializing with a friendly group of guys and gals.

The earlier birds will be there at 7:30 AM (or even earlier) but the official start time is 8:00 AM.

Next breakfast will be August 12th 2017.

Hello All,

Next breakfast will be August 12th 2017.

Enjoy some delicious food, get your DMR questions answered, arrange to have a code plug loaded onto your radio.

It’s the best way to catch up on the dynamic world of DMR in Minnesota while socializing with a friendly group of guys and gals.

The earlier birds will be there at 7:30 AM (or even earlier) but the official start time is 8:00 AM.
See you then.

Magic Yard Sale

The Magic repeater club is having it’s annual yard sale this Saturday July 10th at 8am. Sellers should be onsite at 7am for setup.

Location: Galilee Lutheran Church, 145 N McCarrons Blvd,  Roseville, MN 55113

Free admission for buyers. Sellers pay $5.00 which will be donated to the Church. Please bring your own table and chairs.  Talk in on 145.170. 100.0 tone or DMR MNStatewide(3127) – Give a holler for K0GOI or 444.050 PL 114.8Hz

See you there.  You may have a chance to play with the new TYT MD-2017 dual-band DMR radio. Terry plans to have one on display.

Maximum Coverage from DMR systems

So recently heard on the air was a discussion about working DMR systems from an airplane; During that talk, there was a claim the repeater was able to be worked with a full bi-directional conversation from a couple hundred miles away.

I was really surprised. I’m fairly sure reception is possible over tremendous distances, but you would be unable to hold the proper time-slot with a TDMA network like Tera and DMR.

Here’s a discussion I found online:  And here’s an FAQ from Tait:  and:  and:

I thought I’d toss this out there to see what others may know or think about this?

I wondered if maybe its possible but you risk stomping on the other time-slot had there been two time-slots in use towards the repeater?

I’m quite certain that with DMO mode aka a Simplex radio connection where there is no need for syncing or precise timing, there would be no problem. This impacts only repeater operation where both time-slots are in use.

For anyone wanting to claim D-Star and Fusion are better than DMR, this might be one example of where they may be. But I’m happy with DMR and it’s ability to carry two conversations from one pair and it’s lower power consumption. The world is full of trade offs.

I love Brandmeister – Easy as Pie to manage Talk-Groups

I’ve uploaded a video to show you how easy managing talk-groups is for repeater owners/operators.
You can make changes in mere seconds and any hour of the day or night without bothering anyone with your request.
I do hope other repeater owners in Minnesota will consider moving over someday. If you as a user prefer Brandmeister connected repeaters, please mention that to the repeater owners you talk to.
Check out this video.

Minnesota Statewide Talk-Group 3127 moving on many repeaters to Time-Slot1


In an effort to make the repeater network available to all users, many of the repeaters in town are moving Talk-Group 3127 (Minnesota Statewide) over to Time-slot 1 and thereby opening up Time-slot 2 for Push-To-Talk (PTT) activity. This clears the way for QSO’s to move to TAC channels or Local9/Local2 without conflict from MN Statewide. The Brandmeister network supports thousands of other talk-groups too. Anything can be brought up on either Time-slot PTT.

The following repeaters have Minnesota Statewide on Time-Slot 1 Full time…
BLM(Bloomington), (CSK)Chaska, MTK(Minnetonka), CTV(Centerville), STP(StPaul)

For the next 10 days or so… CSK and MTK also still have 3127 on TS2 full time… Yes 3127 is full time on both time-slots. This was done to support users of roaming and those who have not yet updated their code-plugs.

All of the above repeaters also support PTT for 3127 on TS2, again, so if you have not yet updated your code-plug, you still have Talk-Group access. Galen has already released code-plugs for the TYT radios and he expects to have the other radios done tonight too.
Dave will be releasing updates for the Motorola repeaters shortly.
Thank you to all the site providers, repeater owners, code-plug and cbridge/network maintainers.

There are a few other repeaters also likely moving, so I’m expecting a couple code-plug changes in the near future.
73 – NØNKI – Eric Osterberg