Altus gear not getting GPS

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DarthMuffin

DarthMuffin

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So I have a new v3.0 Altus TeleGPS and a Telemetrum. Neither one are getting a GPS lock. They are in a clear outdoor area with the GPS chip facing the sky, no metal or obstacles around. Tried reflashing firmware with the latest (they already were). Using their battery, and it's at 4.14V right now. The TeleGPS never gets a GPS Lock, I've left it running for an hour and most I get is "0 in soln, 7 in view", usually less. The Telemetrum will get a GPS lock but only after 10 to 15 minutes, which won't be reasonable to ask the LCO to wait that long. Plus if it loses lock on ascent, no way it will relock before touchdown. The Telemetrum had the same behavior at the launch site 200 miles away, so I'm relatively sure it's not some weird interference at my house.

Anyone got any ideas? I've emailed bdale but no reply. I assume he's at LDRS or something.
 
I’ve used the Telemetrum and Telemega, both of which are the newest versions.

The Telemetrum takes awhile to acquire signal on the pad, I’d say at least 10 minutes. I would run your testing in a very open space, like a ball field. I honestly thought I had a bad unit but it really needs a 180 degree view of the sky. I’ve never had it lose positioning once launched.

I think that if you give the LCO a heads up, they wouldn’t be that annoyed. I’ve thought about installing an arming pin that closes the circuit on the charges only. That way I can power up the Telemetrum before I bring the rocket to the pad.

The Telemega uses different hardware and it nails the position in less then a minute, with obstructions.
 
My Telemetrum is losing lock. After the 10-15 minutes to lock it will only stay locked for a couple of minutes, then the cycle starts again. I got to looking at it and did find some damage to the circuit board, not sure if it's related but I'm sure it wasn't my handling of it.

Still no luck at all with the TeleGPS, even with a really good open sky. Just waiting to hear anything from Altus Metrum.
 
DarthMuffin said:
My Telemetrum is losing lock. After the 10-15 minutes to lock it will only stay locked for a couple of minutes, then the cycle starts again. I got to looking at it and did find some damage to the circuit board, not sure if it's related but I'm sure it wasn't my handling of it.

Still no luck at all with the TeleGPS, even with a really good open sky. Just waiting to hear anything from Altus Metrum.
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Sorry if obvious, but have you tried a fresh battery?
 
Are you using APRS by any chance? There was a bug that I believe was never fixed to date. Keith was able to identify it with one of my units and told me how to get around it.
 
DarthMuffin said:
I don't think there's any interference. My eggtracker works, so does drone and phone GPS.
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Have you tried the Altus Metrum product with the eggtracker telemetry off? I have seen GPS receivers desensitised by other telemetry systems nearby. I have observed them taking longer to lock or not locking at all, depending on the proximity of the Tx antenna to the GPS Rx.
 
OverTheTop said:
Have you tried the Altus Metrum product with the eggtracker telemetry off? I have seen GPS receivers desensitised by other telemetry systems nearby. I have observed them taking longer to lock or not locking at all, depending on the proximity of the Tx antenna to the GPS Rx.
Click to expand...
yes, they were never on at the same time. The Metrum and telegps are both out of a rocket (telegps was never installed, decided I would test it first after having the Metrum foul a launch trip) sitting naked running by themselves.

And thanks tim for the group email link. I'll give him a few days before trying that, assuming he's at LDRS and needs a bit.
 
Bdale responded on the Altus Metrum FB group -- was obviously at LDRS but his daughter is getting married this weekend too. So I'm cool with waiting, just good to know. I just hope I'll be able to use these this summer! Will have to cancel my BALLS trip if they're not fixed.
 
DarthMuffin said:
Bdale responded on the Altus Metrum FB group -- was obviously at LDRS but his daughter is getting married this weekend too. So I'm cool with waiting, just good to know. I just hope I'll be able to use these this summer! Will have to cancel my BALLS trip if they're not fixed.
Click to expand...
I have flown many TeleMegas and TeleMetrums, but none were the latest version. They usually take five or fewer minutes to acquire GPS lock. I'm not sure how you are doing your testing, but I have one TeleMega that doesn't report GPS lock in Idle Mode, even though I'm certain it has lock. My usual testing scheme is to mount the unit on its sled, take it outside, and power on in vertical orientation so it boots to flight mode. After the power-on beeps complete, I lay it horizontal so the GPS antenna is pointing up, and connect to it through the RF link with AltusDroid on my phone.

...Fred
 

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