TeleGPS from Altus Metrum - GPS tracking with digital telemetry, APRS and RDF

Bdale and I spent the weekend at Mile High Mayhem testing our latest product, TeleGPS. With everything working great, they're now available for $200 from the Altus Metrum Web Store

• uBlox MAX 7 GPS receiver
• 16mW 70cm transmitter
• 17 hour on-board logging memory (at 1 sample/second)
• Built-in USB for configuration, battery charging and data download

Bdale wrote up a bit more about this on his blog

Very cool, guys.

Hi Keith:
Apogee is showing a 400 and 850 mAh battery for this gizmo. Your web store has both a 160 and an 850. What are you recommending for typical use?
Thanks in advance for any advice!
Best wishes,
Will

WillMarchant said:

Hi Keith:
Apogee is showing a 400 and 850 mAh battery for this gizmo. Your web store has both a 160 and an 850. What are you recommending for typical use?
Thanks in advance for any advice!
Best wishes,
Will

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I wrote up some battery life research I just did with TeleGPS https://keithp.com/blogs/TeleGPS-Battery-Life/. In that example, a nominal 160mAh battery (actually labeled as 200mAh) lasted for six hours. In a separate real-world example, Joe Bevier used TeleGPS to track pieces of the OSU project at ESRA this year. That lasted for 24 hours on a nominal 850mAh battery, although was down to 3.6V by the time they found it, which is pretty close to the limit.

Apogee is reselling 400mAh batteries that they're getting from SparkFun, and those are a really good size for TeleGPS, just slightly smaller than the PCB itself. We aren't reselling those because they come with the current limiting board which makes them unsuitable for use with our flight computers as they will shut down the flight computer when firing pyro charges. I'd estimate that these should last around 12 hours or so.

All else being equal, longer battery life is good insurance, so pick whatever fits your comfort zone and ebay the best

Thanks, Keith! And do you happen to know if the TeleGPS APRS mode plays well with the Kenwood TH-D72?


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WillMarchant said:

Thanks, Keith! And do you happen to know if the TeleGPS APRS mode plays well with the Kenwood TH-D72?

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Yup, works great with those. That was the first radio we tested our new APRS code with.

keithp said:

Yup, works great with those. That was the first radio we tested our new APRS code with.

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Very nice, thanks, Keith!


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It also works nicely with the super-cheap ($34) Baofeng UV-3R with the Moblinkd external TNC.

Just a few questions.

Has anyone used this near a Raven? I want to know if it will cause any interference.

Also where can I find the dimensions?

"yields a board that is 1.5 x 1.0 inches (38.1 x 25.4 mm)." https://gag.com/bdale/blog/posts/TeleGPS_v1.0.html

not sure if that includes the battery pack or not.

Tony

tfish said:

"yields a board that is 1.5 x 1.0 inches (38.1 x 25.4 mm)." https://gag.com/bdale/blog/posts/TeleGPS_v1.0.html

not sure if that includes the battery pack or not.

Tony

Click to expand...

https://altusmetrum.org/TeleGPS/ gives those dimensions and adds that it will fit in a 29mm coupler.


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tfish said:

not sure if that includes the battery pack or not.

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The battery is even smaller.

JohnCoker said:

It also works nicely with the super-cheap ($34) Baofeng UV-3R with the Moblinkd external TNC.

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John,
I have the Baofeng radio. Can you share some info on the Moblinkd or perhaps a link or two?

JohnCoker said:

The battery is even smaller.

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Is that the 400 mAh battery from Apogee/SparkFun, John?


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chuck5395 said:

John,
I have the Baofeng radio. Can you share some info on the Moblinkd or perhaps a link or two?

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https://store.mobilinkd.com/

Get the Kenwood cable and a ferrite bead. You'll either need to pair it to a laptop with a tracking program on it or an Android device/phone.
APRSDroid is an app that can be used.

https://aprsdroid.org/

Now if your phone has an internet connection, one can download maps in realtime. If one just has an Android device like a Nexus 7 Flo (no phone WiFi only)
a version is available for use with free OSM maps.

https://aprsdroid.org/osm/

Only thing I find a problem with APRSDroid is I have to send a position packet to get my location to change on the map when navigating "to" a target/rocket. Trying to
figure out if there is a switch in the program that will show my position in realtime on the OSM maps without having to send an Rf packet.
Not a big deal and the system is workable. The price of the APRSDroid is right (free with the capability to use free maps unless one wants to donate to the author)

I don't think to date the iPhone has a B/T capable APRS program that can pair to an external B/T TNC. Correct me if I'm wrong here. Kurt

WillMarchant said:

Is that the 400 mAh battery from Apogee/SparkFun, John?

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No, I purchased that from Bdale's web store.

ksaves2 said:

I don't think to date the iPhone has a B/T capable APRS program that can pair to an external B/T TNC. Correct me if I'm wrong here.

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PocketPacket has a software TNC; just waiting for my connectors to arrive to give it a try.

JohnCoker said:

No, I purchased that from Bdale's web store.


PocketPacket has a software TNC; just waiting for my connectors to arrive to give it a try.

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Ahhh,

Software TNC so one has to take the audio off the earphone jack and get it into the device? If so, it's like the Mobilinkd in that one has to have the volume
set at the appropriate level and not "jiggle" it or it will lose the decode on the packets. (Been there and done that too.)
If triapsing around in the field one needs to take care not to lose the setting. I scratched a mark on my radios so I can keep the setting pretty close.

Direwolf is a software TNC I've been impressed with if one would like to have a base station that just requires a laptop, tracking program, direwolf and any scanner that can receive he desired frequency. (Use YAAC or Xastir and if you have a scanner and earphone cable lying around can cobble together a free
tracking base station for receive only.)

Direwolf https://home.comcast.net/~wb2osz/site/

YAAC https://www.ka2ddo.org/ka2ddo/YAAC.html

I have an old NASCAR scanner I plugged a cable from the earphone jack to the microphone in on the laptop
and Direwolf decodes packets into a variety of tracking programs. Not easy to carry around pedestrian mobile to the landing site though.
Like I said, it might be free if you have an extra radio receiver and laptop lying around. Kurt

BLKKROW said:

Has anyone used this near a Raven? I want to know if it will cause any interference.

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Adrian has flown an original TeleMetrum right next to a Raven; that has essentially the same radio (differs in power by a couple of dB).

WillMarchant said:

Is that the 400 mAh battery from Apogee/SparkFun?

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As John mentioned, this is one of the 160mAh batteries that we sell. The 400mAh batteries from Apogee/SparkFun work great with TeleGPS and are just slightly smaller than TeleGPS itself, but the absolutely must not be used with a flight computer that will fire pyro charges as they contain a current limiter board which will shut down the flight computer while firing charges. I'm looking around to see if we can source some of that size without the current limiter board; we really don't want to sell batteries that won't work with our flight computers.