APRS, Mobilelinkd TNC2, CoPilot and Tablet

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I’ve been using a Garmin RV760LMT GPS for the last year, with good results. It is a good little unit, but there are a few things I’m not thrilled with. First, the ball failed to properly hold the GPS so I had to modify the mount to hold it properly. The modified mount holds it at a strange angle to view from the driver’s seat. Second, the FM receiver for traffic updates is built into the charger, which also failed. I replaced it with a Garmin brand charger, not realizing at that time that meant giving up FM traffic updates. And last, you can still get traffic updates with the prior if you use bluetooth to connect it to your phone, but in practice this only works about half the time. So essentially I’m without traffic updates at least half the time and the mount isn’t great. The maps and routing rarely lead me wrong and overall I’m still happy with the unit. However, with the APRS support built into my TM-D710G, I wanted to look at ways to display received info on a map.

I have a hotspot I’m paying for on my Verizon account that I’m paying for and not using, since I’m leasing an unlimited data plan from elsewhere. I looked into my options and was able to upgrade this line to a new Samsung Galaxy Tab E 8″ for a reasonable price, and opted to do it. So I’ll have a 4G connected tablet on Wednesday for a one time upgrade fee and no increase in monthly charges. That also means I’m not throwing away $10/mo for nothing.

I went to Amazon and found the RAM mount specific for this tablet as well as the connectors to mate it to the dash. It is 1/2″ taller and almost 1″ wider than the Garmin, but with the assistance of RAM mounts I should be able to put it into an more usable position despite the larger size. I also ordered a Mini-to-MicroUSB adapter for a couple bucks so that I don’t have to pull apart the dash to make the change. Those panels only come apart so many times, and I’m trying to limit how many times I’m stressing them.

For sending the APRS data from the Kenwood TM-D710G, I need a bluetooth TNC and an appropriate cable. I opted for a Mobilelinkd TNC2 and their MiniDIN-6 cable, which will interface completely with the base mounted under the rear seat and not require any new cable runs. With that combo, I will be able to load up APRSDroid, and map APRS data on the screen.

This is a screenshot of the APRSdroid application I found on Google Image Search:

So it interfaces with the radio and will display received APRS beacons in your area, map them, and even allow you to send messages to other APRS users via the APRS protocol.

Next, I’m going to use CoPilot RV for GPS. When I purchased the Garmin, there were no truly size-aware options for GPS on Android, and that has since changed. I used CoPilot in the past for vehicle use, and it worked great. I am also looking at their Truck GPS software, which has some more features. Either way, I’ll end up with CoPilot GPS on the tablet, which has a built in GPS receiver. I’ll be back to getting reliable traffic updates through the 4G LTE connection, and even be able to use alternate GPS software when looking for a second opinion from the same device.

To properly interface the tablet with the vehicle, I will be using Tasker. The main reason I will be using this app is to detect power (which will be triggered by the ignition) and sleep/ wake the device accordingly. This has apparently come a very long way since I’ve last tried it, and is very usable now. I will be using bluetooth on the tablet to connect to the truck’s audio system, and will add a 128GB microSD card for Spotify’s offline playlists function as well as the CoPilot offline maps.

This solution should completely fulfill the requirements I have for GPS as well as give us a lot more flexibility to do other things, including display APRS data and manage a large media library. The install will require minimal work and should interface cleanly with everything already in the truck. And it works out to be substantially less than I paid for just the RV760LMT GPS a year ago.