Bluetooth Module for Kenwood D710

dreadlocks

Well-known member
How to build a Bluetooth Module for the Kenwood D710, plugs into the COM port on back of Remote Head Unit (NOT THE GPS 2.5mm PORT) and passes on raw aprs packets onto APRSDroid, this gives you full (READ ONLY) information in APRSDroid while your 710 is doing all the APRS Stuff.. You can switch the 710 into a simple TNC and APRSDroid will do full two way control of the radio, sending position packets, messages.. etc.

Amazon Parts List:
Assembly:
IMG_20190726_180134.jpg

You need a good wire stripper that wont destroy the fine wires.. tin all the wires, put the power for the BT and VReg together w/solder and then solder everything into the holes on the TTL Converter.. pretty self explanatory.. RX goes to arrow pointing towards BT, TX goes to arrow pointing away.. VCC to + and GND to -

Configuration of APRSDroid:
Screenshot_20190727-181645.png


Screenshots in action, using APRSDroid OSM version for offline maps.
Screenshot_20190726-182143.pngScreenshot_20190726-182123.png
 
Last edited:

DaveInDenver

Middle Income Semi-Redneck
How did you make APRSdroid read-only? I'm only able to get it to listen for packets by starting tracking, which seems to be what initiates the Bluetooth stack. That's fine I suppose but it seems to enable the TX logic, which I set to manual but it'll still burp out the occasional packet for some reason. And since I've set position to manual (e.g. it's not using the location from the phone nor Smart Beacon nor periodic beaconing) I end up with a few beacons at the default location, which seems to be the Equator on the prime meridian.
 

dreadlocks

Well-known member
nice, I dont think argent sells those w/the radio anymore.. I always wanted one of them.

I see your hamshackle APRS setup, and raise you my trailers GMRS Repeater + APRS Tracker.. but dusty but its all tested ready for its final install I'm working on now. .

IMG_20190728_114444.jpg

and for more cock waving, here's my home hamshack.. right now mostly running an APRS iGate/Digi for all denver metro..

IMG_20190728_115541.jpg

Now I'm saving up for a nice Dual Band APRS Handheld w/Bluetooth built in so I can carry it on my dirt bike/backpacking.
 

DaveInDenver

Middle Income Semi-Redneck
My point was just to show the BT dongle I tripped across, which has the 5V regulator and RS232-TTL level interface built-in. Byon sells them for I think about $40 and it reduces cabling very significantly since it's designed to work with the quasi-standard ham APRS TNC DB-9 pin outs.

IOW, pin 4 is +5V, pins 7 and 8 are port B, etc. It can also pass-thru port A if you (or maybe just me) want to send/recv NEMA/waypoints from an external GPS receiver. I actually could remove the 'Y' cable but I use the BT dongle with my TT4 sometimes and also have no access to a 3D printer to make a decent housing for the thing, so it's pretty exposed and hanging another cable on it just screams "Break off PCB-mounted DB9s" to me.
nice, I dont think argent sells those w/the radio anymore.. I always wanted one of them.
Friendcom stopped making the radio because it will overheat if you push it. Running very infrequently it settles at about 95°F to 100°F but with even modest Smart Beaconing settings it'll sit at near 150°F. I'll usually see about 10% duty cycle over an arbitrary 10 minute period with a lot of heading changes, so it's not excessive relatively. So it's actually not a great APRS radio since it's intended use was very infrequent data, like sending a temperature reading once an hour or something similarly undemanding.

They replaced it with the FC-302 with a proper die cast case but I haven't seen any for sale. So I have been stockpiling Maxon/Midland SD-125V2 radios when I see them for a decent price to eventually replace the FC-301s I have. Won't be as easy to stuff a TNC inside, though.
Now I'm saving up for a nice Dual Band APRS Handheld w/Bluetooth built in so I can carry it on my dirt bike/backpacking.
I broke down and bought a Mobilinkd. I gotta say that plus an HT is really hard to beat. His newer TNC3 is BR/EDR+LE so can be used with iOS and the aprs.fi app on it can pair with for over the air APRS. It's not as well developed as APRSdroid but it works alright.
 
Last edited:

dreadlocks

Well-known member
I have an original MobileKind here, they are neat.. but I want something all in one for field use.. that has the GPS/Bluetooth all bundled in so my phone can sleep and not burn its battery too.. want dual band so I can mod it to talk to my son on his bike via GMRS without carrying multiple radios and dongles and parts to break on me.. The FT3DR is what I'm eyeballing. Mamma is back at base camp, out of cell phone coverage going to monitor us for piece of mind and meet up w/us if we need assistance (fuel/flat tire/mebe lunch).. something like a sat beacon wont reach her.. but N0AUX there and AC0VP do a really good job of covering alot of the Rampheart trail network.. and if we're somewhere else without such good coverage I'll use my tow vehicle as a fill-in digi and park it someplace high between the trails and our basecamp... I MIGHT get a PicoAPRS unit to put on my son's bike, and make its first hop my bike then set up its display to always point to my position, just incase we get separated on the trail.

Didnt know about that Bayonics BT module, looks like it'd still require making a custom cable for.. but ya that'd be nice and clean.

73's
November Four Yankee Romeo Echo
 

dreadlocks

Well-known member
How did you make APRSdroid read-only? I'm only able to get it to listen for packets by starting tracking, which seems to be what initiates the Bluetooth stack. That's fine I suppose but it seems to enable the TX logic, which I set to manual but it'll still burp out the occasional packet for some reason. And since I've set position to manual (e.g. it's not using the location from the phone nor Smart Beacon nor periodic beaconing) I end up with a few beacons at the default location, which seems to be the Equator on the prime meridian.

Sorry I just saw this, going through the COM port on the back of the 710 is read only while the 710 is in APRS mode.. at that point it basically just spits out a TNC log over serial so APRSDroid can send all it wants but its ignored by the unit.. If you reconfigure the 710 to be in TNC mode vs APRS, then the serial port is bi-directional KISS Console and APRSDroid does everything... I dont want my phone to be a requirement to be powered and in the vehicle for it so I'm not using that.. the only benefit I see is I could type out messages on my phone instead of with my DTMF mic.. which if I got into heavy msg traffic I could just switch over too.. usually messages are just: here/okay/coming home and I can handle typing it out like I have a flip phone.

Suppose you could always snip the TX wire, tha'd make it Read Only :p
 
Last edited:

DaveInDenver

Middle Income Semi-Redneck
Sorry I just saw this, going through the COM port on the back of the 710 is read only while the 710 is in APRS mode.. at that point it basically just spits out a TNC log over serial so APRSDroid can send all it wants but its ignored by the unit.. If you reconfigure the 710 to be in TNC mode vs APRS, then the serial port is bi-directional KISS Console and APRSDroid does everything... I dont want my phone to be a requirement to be powered and in the vehicle for it so I'm not using that.. the only benefit I see is I could type out messages on my phone instead of with my DTMF mic.. which if I got into heavy msg traffic I could just switch over too.. usually messages are just: here/okay/coming home and I can handle typing it out like I have a flip phone.

Suppose you could always snip the TX wire, tha'd make it Read Only :p
So APRSdroid isn't RX-only you're just dumping its TX attempts in the bit bucket. What I've done is set Location Source to Periodic with 999 minutes between beacons. It still pukes out one packet when I hit Start Tracking but doesn't attempt one again for any practical length of time.
 

dreadlocks

Well-known member
You tried Manual Coordinates and then uncheck Automatic Posting? Though I do see your issue, I dont think you can 'Connect' without hitting that "Start Tracking" and that might force a position beacon out.. though I think I only had to press that once and since its been auto-reconnecting when I get in the car.. might not after a reboot though.

Screenshot_20190729-163730.png
 

DaveInDenver

Middle Income Semi-Redneck
I have tried Manual Position and that does the job, but it still dumps out a packet when you start and being manual position it'll either use the default or the last one it has. So your track gets a random location. It's of course just an annoyance since the next beacon gets your location corrected.
 

Forum statistics

Threads
185,529
Messages
2,875,555
Members
224,922
Latest member
Randy Towles
Top