My anytone 578 is acting up. Seems like a bad oscillator. I could do one of two things… I could take it out and try and track down the issue, that is, why the squelch almost seems permanently open, like a birdie, but only after it’s been on a while, and seemingly gets affected by vibration… or.. oh to heck with it. Going back to commercial gear. XTL for VHF, and XPR for UHF. That’s the long term plan, anyway.
One problem. Switching to these radios means I no longer have an integrated dual band radio with built-in APRS beaconing. I kind like having a tracker on for longer trips. That presents a challenge. I need a dedicated solution. The last DEDICATED APRS tracker I had was a Yaesu FT1500 with a KPC3+. I had intended on using an MCS2000 once upon a time, but I think I ran into some issues, and never actually got it functioning.
It just so happened that I stumbled on a deal on a “new in box” XPR4350. First thing I had to do was learn what the different models of XPRs were. They didn’t seem to make sense like the XTL and XTS line… well… maybe they do, and I was just not used to them. After some research, I put together a cheat sheet to ID the radio by model
Turns out it was VHF, so not of much use for most amateur DMR purposes. But the wheels were turning. Once I got the cqodeplug unlocked (that’s a whole other bit of fun), I decided this radio would be an ideal candidate for an APRS tracker. Note that I’ll be on the hunt for an XPR5550 Q split. Hamfests and prayer.
A side note (I do that a lot, but this time I’ll at least call it out). One thing that I spend the most time figuring out for this radio was a codeplug layout. I decided on the following:
| Zone 1 | Zone 2 |
| APRS- 144.39 | NOAA 1 (auto scan) |
| 146.52 | NOAA 2 (auto scan) |
| 146.55 | NOAA 3 (auto scan) |
| My local Club Repeater | NOAA 4 (auto scan) |
| Backup Repeater | NOAA 5 (auto scan) |
| Club Simplex | NOAA 6 (auto scan) |
| DMR Simplex 1 | NOAA 7 (auto scan) |
| DMR Simplex 2 |
Button 1 is Monitor (short press) / Unprogrammed (long press)
Button 2 is home channel (APRS) (short press) / Zone Select (long press)
so far this seems like all I would generally want. Now back to the project.
I picked up several rear accessory connectors from WisComm ($5 each, versus $20 on amazon). I wired one up with the cabling for a TNC, but also added an ignition sense wire, and cut the end off an old keyboard USB cable, and connected pins 1-4 to this connector for programming. I turned off the power on test tones, and pushed the codeplug (also turned on ignition sense, so now I need an extra alligator clip to do anything to it. Minor inconveniences.
On to the TNC. Wait… what TNC? Well… somewhere, I do have an old TinyTrak (2?) in an envelope. I think I can do better. I was looking at APRS.fi for the iPhone. Bluetooth would be a cool way to hook up to it, and then have some live display stuff from time to time, whether it’s on my iPad or phone. So let’s dig into what I wanted.
- KISS mode ability, so the phone or iPad can do some display work
- bluetooth because, well, expecting a physical serial port on a phone is…well.. no.
- runs on 12V
- serial port for GPS input
- has external GPS antenna input
- internal APRS functionality – acts as a standalone tracker when nothing’s connected
So there’s a few options:
- Tinytrak 4 plus Bluetooth module
- They’re expensive, I’m cheap, and the bluetooth module is out of stock
- Looking at it, the BLE module may not be fully compatible with iOS?
- Doesn’t include a GPS, so I’ll need to find one of those
- Mobilinked TNC
- No automagic APRS when no phone is connected
- Also needs a GPS
- Argent data systems Tracker3
- No built in bluetooth
- cheaper than TT4
- See the trend? This one ALSO needs a GPS.
- Chinesium APRS tracker thing on Ebay and Aliexpress
- $60-ish
- minimal documentation
- internal GPS (only?)
- Not brave enough to try.
- RPC Electronics ESP32 APRS Tracker
- https://www.rpc-electronics.com/esp32-aprs-tracker.php
- Would be absolutely ideal – includes all features
- A little cheaper than Bionics, but includes all the features, no extra parts
- …damn. he quit making them.
- ??
Decisions, decisions. Well, for $40, I ordered a Tracker3 mini (“T3M”) from Argent. I also ordered a cheap GPS module that had not only an integrated patch, but also an SMA connector, as well as a 5V power supply module, and a couple HC06 Bluetooth BLE modules.
Once it showed up, I started putting things together on a perf board. For some reason, I thought it needed RS-232 to TTL adaptors… later proved that wrong. While the T3M will generate 5V for some things, it’s not enough to provide power for the GPS and other accessories, so I will need that external adaptor when it shows up.
With a little messing around, I did finally learn a couple important things:
- HC06 doesn’t play nice with iOS. If I had android, this might not be an issue.
- AT09 marginally plays with iOS. I can find it with some tools, but not so much with APRS.fi.
- A better option to add BLE will likely be the adafruit BLE UART friend. It can be set up to comply with the BLE KISS API (listed below). I think this might be necessary to set up the appropriate UUIDs, which could explain why BLE terminal tools can see and work with the AT09, but APRS.fi won’t.
Playing with all this… I eventually smoked the 5V regulator on the T3M board. I could feed 5V from a power supply, and some things would work. I actually used an Arduino board to provide the 5V. I tried passing port B (GPS) to port A using the “SNOOP” command. At one point it worked, once I blew the regulator, I just got trash. I jumped the GPS output to the AT09 input, and saw tons of GPS traffic ($GPGGA and the like) on my iPhone BLE terminal, so I know the pieces work, just not the bluetooth / TNC interface. I think I’ve convinced myself that a BLE module alone won’t meet the “BLE KISS TNC” protocol, so that will need to move to the adafruit solution, if I can figure it all out.
At this point, I’m into the project for about half of what the TT4 would run. When I factor in buying a replacement T3M, and then the adafruit module, I’m probably at about the same price, but with ALL the functionality I want… oh… and if I needed to add a GPS to TT4, that would be another 70 bucks, if I bought his…. so I’m still ahead, though I know his stuff is turnkey and works out of the box (what about the BLE?)
As of now, the plan is to add an Adafruit Bluefruit BLE “UART Friend” – a BLE that can be set up to mimic a KISS TNC device. The T3M is on order… I think I’ll breadboard it this time. Here’s the planned interconnect thus. far.
