Experimenting with our Pi-2 and DMR Ham Radio

   To try somthing new and to use tech from our RC car we made we decided to add a MMDVM "hat" board to out PI 2.(Nicked as a 'hat' as it mounts on top of the Pi boards)  A MMDVM(Multi-Mode Digital Voice Modem) works with several ham digital modes to make a hot-spot.  A hot-spot is a link from a DMR radio to the internet that is linked to a worldwide ham radio DMR network.  It is thus possible with DMR to talk to other Ham operators around the world while both being on a mere handheld radio.  The mode we are interested in is DMR(Digital Mode Radio).   It is the least expensive mode to get into as its technology is well established for commercial radio communications.  Even so we will not be getting a DMR radio to use right away and will wait for a used or bargain model.

   Towards this effort we plan to add the MMDVM and a 2.4" Nextion resistive touch screen($16.40) to show freq, mode, power and tx/rx to our existing Pi 2.  We purchased a clear shell for our RC car and plan to try to mount the screen under its wind screen, thus using the RC car as a base for our hot-spot.

   Right now the plan is to make the hot-spot togather as a useful electronic project.  At a later point we will get a used DMR radio, yea we can get a new Baofeng for $49 but a used TYT MD-380(new $82) or similar model would be a better radio.  Patience gets the best deals, and we're still building the hotspot so are in no hurry.  Even more patience and saving an extra $30 would get us a new and better radio than the Baofeng.

   April 23, 2019 😕 I just saw a used TYT MD-380 for $69 on Ebay without the antenna or battery,  that could only sell to someone who already has an extra battery and antenna as the cost of buying battery and antenna would cost more than a new radio.  Personally we like most, would rather buy a new one for $13 more rather than a used one and missing parts. 😕

  The reason we need to use a hot spot is that in Eugene there is perhaps only one DMR repeater(kc7rjk) although I have not got a response from the owner.  DMR repeaters are usefully hooked up to regional or national networks(ie. PNW and Oregon DMR fb group) and thus limits communications of peer to peer or specific groups of people(called rooms) you may with to talk to (for 10 minute spans).  I have made Friends with a DMR group from Germany I would like to talk to without having to be at the mercy of the common networks.  So far we have only messaged members on Skype and talked via a phone PTT app and one phone call with a member.

   Update May 9, 2019  All done and seem to work and says Idle as expected, but  I would have thought the IP-Address would get past "Logging onto network and  "Initializing  wait" would change to the current IP address.  The real test is if we ever get a radio, but it was fum making somthing useful of the old car project anyway.

Here area few pics:

Old Pi-2 powered RC car with a new clear shell as a dust cover will
 house and show the 2.4 Nextion screen of the DMR MMDVR hotspot.
"Calling car K7VIQ...." 

DMR mode screen that I like and would like to see frequently.
Screen created by G0FEA

Idle mode. We will see a lot of this screen
 until we actually get a DMR radio.
Screen created and shared with other hams by G0FEA

Nextion screen with MMDVM hat board and
70cm antenna mounts to a Pi board.

Antenna MMDVM hat board and 70cm antenna

Kathy holding our previous car project,
the foundation for its new life.

The 1/18 scale shell we hope to use with our car for dust protection
and for the project to seem a bit more finished.

Not our car but the same shell painted to show detail.

So far with our Baofeng UV82-HP ham radios

    We have both of our new Boafeng UV82-HP radios programed and working.

    For much of a day I spent trying to get a tail back from repeater and was unable.  Although our simplex tests worked, my main hangup to getting a tail back from the repeaters I found was I needed to reduce the squelch so as not to block the weaker signals of our repeaters.  I had been setting a squelch of a level of 5 as I have always used on other radios I have had, but found for this radio a level of 1 is best as programmed.  The squelch range is programmable on this radio and I had changed it as suggested by Maklor.com to a different range.  If I find I do not like the range suggested by them as I become more experienced as I use the radio with varying signals I have the opportunity to change it.
 
    A local ham operator "Matt" from the Eugene 145.45- T123.0 repeater has welcomed us to use his repeater that sits on Blanton Heights 7 miles away.   The signal is a bit weak from our HT (handhelds) and so we need to use all 7 watts to give the repeater a decent signal.  The owner reports that as long as we speak up and directly to the mic it gives an adequate signal.  As far as receiving, I do wish his signal wasn't buried in the white as it is, but it is a lower power repeater.  I do hope to get access to a repeater that does not require full power to use and has less white noise, or better antennas. This repeater will do quite nice tho for practice with using a repeater before we add a higher power repeater to our goto list.

    I am finding that I am using two of the stock 2800mAh batteries for all day listening with very few short 7watt transmissions.  I am happy that when I bought the radios I purchased an extra battery pack for each of them.  I also purchased 1(one) Alkaline battery pack for when away from power and a car power pack adaptor.  So we hope we are all set for our emergency radio power needs.

    I am considering some sort of dual band J-antenna to use with our radios to help in emergency situations to get out.  I may just set one up here on our porch for better local communications. The disadvantage of a J antenna is it would need to be stationary to use.  I would need to find one with a Male Female-SMA connector (Why can't there just be one standard so it is not so confusing) 

   For mobile use Baofeng suggests these Nagoya antennas that I am looking at.  I am considering whether an 8.5 (more mobile) or a 16" (better range, but pretty long) antenna is wanted for better mobile operation. The radio came with an 6.5" antenna which in of itself is said to be an already a good stock antenna so I don't know that 8.5 inch is much better than the stock 6.5". Will 2"antenna difference really matter that much?

Also available is a 4" antenna that extends to 15.6" for transmitting. (Can not transmit when collapsed). I have used a 2m extendable antenna before with good success (It is mobile + some length for more distant reach). So many options to consider, I'll let you know if I ever pick one. For now the initial radio purchase is enough.

A couple hams that we am once again.

We had a couple of these Baofeng UV-82HP HAM HT radios that shipped in blue from Baofeng USA yesterday.

  We have been away from ham radio for many years and are getting back into it using the Baofeng UV-82HP radio's and plan to use them enough so that we are comfortable with them and review general HAM radio practice so we are ready as possible to use them just in case for emergency usage.  Their strength is in being able to reach out further, and use repeater systems in an emergency over our GMRS radios to use with our non ham friends and family. 

We also picked up a couple of inexpensive open box MSC-20C straps for them from ebay. I do not pick up a lot of open box stuff other than when it is non electronics. Update:10/25 My reason for not usually getting open box stuff was emphasized as Both pouches need some sewing repair on the stitching of the fabric holing the plastic clip to the flap cording, very repairable as it is not an electronic device but a distraction from being able to putting them to use non the less as we will need to get some heavier duty black thread to repair.

This is another part of our continued effort to update our emergency Go-Packs we have been trying to do over time.

73's K7VIQ and KD7PJW (GMRS family call - WQYS231)

GMRS Radio

  We have not been active with our ham radio hobby for years as we ran out of all but a couple locals to talk to and we could not afford all the equipment it takes to be on the HF bands that the Brothers use.  I did however just renew my HAM license that comes due soon.

GMRS - WQYS231

Whisky Quebec Yankee Sierra Two Three One

     Meanwhile, while I was renewing my HAM license that is coming due at the FCC site so I don't loose my HAM call,  I signed up for a General Mobile Radio Service license for the family.  I know it is not HAM radio, but the whole family can operate under one GMRS call with no skill learning required from non-HAM family members.  For 5 family members it comes to $14 for each of us.  While not HAM radio, GMRS is still useful in emergencies and perhaps for us, more so, as well as useful for our family's general mobile radio usage.  For Kathy and I, we are looking at getting a TALKABOUT T465 at a very excellent deal.  Paul, Kathy and Cecil and Earl already have FRS radios but there range is very limited.  These can be can be loaners to others I guess.  There have also been others in the congregation that have talked about using GMRS in emergency situations.  We look forward to having others to talk on radios again.

   I also updated our Ham Radio Page at our Family Web Site to include our new family GMRS call.

Rethinking programming and pondering guitar

   Programming was to much for us to do togather so we did a rethink on a hobby we can do togather and we both decided to try learning the guitar.  We are repairing and adding new strings to to a guitar we received from Dad that used to belong to my Uncle (Gerald).  We started a new blog as we test this new hobby at Acoustic Achord you are welcome to follow as we try a new hobby.

   We will think of somthing else to do with our Pi 2. 

PS: I since moved on from guitar to trying piano and enjoy the rudiments of it.  I will do more with music when I have a better brain.

A second visit to Makerspace and my Wiki updates

    On Feb 12 I took our car to Makerspace to show it.  It did not run much since the Motor batteries ran out of juice rather quickly.  That evening when I got home I ordered 9v power AC power block and a 9v battery clip each with the barrel plug to fit the Arduino source for the Arduino that should also easily power the L298N motor controller and its four 5v motors easily.

   I also took a few photos to bring home to show Kathy while I was there:

I have also been working on a couple Wiki pages at:  Eugenemakerspace.com/wiki/Main/PaulA  The first page is for our car proggress.  I will update it on occasion to update my progress here on occasion and learn new Wiki features over time.  I will keep a sort of a running updated blog.  Old blog posts never get read anyway.

The second wiki page will contain any progress we make towards connecting our second Rpi2 to our television set as another monitoring station for our home security cameras.  Also handy to watch the birds eat from the bird feeders and scratch in the ground under it instead of TV at the same time.

A visit to the local Makerspace and Arduino board test Skript working

  Makerspace

   I went to the local Eugene Makerspace shop tonight for 6:00pm friday open night.  There were about 11 there including women and children.  Tuesday night at 6pm is also an open access night.  For full 24/7 shop access there is a $25 monthly fee.  Four of us there were visitors checking out the environment, expertise and tools available.  It is a small but nice work space to build small wood, electronics and other projects.  Many of the tools available were contributed and even rebuilt to make usable.  They have woodworking tools: Small table saw, routers, sanders, etc.) Hand tools: Wrenches and the like are available.  They also have a laser printer that was recently rebuilt by members.  Two older 3d plastic printers are also being repaired.  Available also is a vacuum former and vinyl printer.  As can be seen here, the shop is offered for a wide variety of type of projects.

Our Car

   We have built our 4wd car and are now working on learning to program it using Python on the Rpi2 and Skript to control the Arduino Compatible Mega 2560 R3 board.

   So for all we have running is an Arduino Skript I found on the internet to make the motors run through a test routine.  I need to learn now to control the Arduino board using the Rpi2.  I will be experimenting with code I find on the internet and trying to adapt it to our particular hardware.

       Our Hobby Photo's Collection < link including videos