I had an interesting problem this weekend when launching. I would turn on
the TeleMetrum on the pad, open up the software on the computer, and get a
good signal and have no problem reading the telemetry from the board.
However, after a few minutes (5-10?) the computer appeared to quit
receiving data (the age would start to climb). I would try to restart the
software, but when I went to monitor flight, it would show N0CALL in the
callsign window. I went out to the pad, and the TeleMetrum was still
beeping as it should, so I turned off the avionics, took down the rocket,
opened up the avbay, checked everything through the USB port (all seemed
OK), put it back on the pad, turned it on, started up the software, and
regained telemetry. However, after 5--10 min I again lost telemetry and
couldn't get it back. I went ahead and launched the rocket as I was flying
with a Raven 2 and using TeleMetrum deployment as backup, and I didn't
expect the flight to go OOS. It flew very well, data file downloaded post
flight showed that all events occurred as planned (all charges went off),
and it had an accurate GPS track as well. So aside from telemetry, all
appeared to be just fine. Unfortunately, I didn't have another
computer/dongle to see if that would receive signals from the rocket.
I have flown this rocket several times now, always with a Raven/TeleMetrum
combo, and it has worked splendidly everytime (except for the flight
before it was known to need the battery mod- all my batteries have
the protection circuit removed now). Never had any trouble receiving
before. I haven't had a chance to test it at home yet. It was hot on
Saturday, but no hotter than the launchesd in June and July, both of which
were perfect.
Any thoughts on what is happening? I will update once I am able to do some
further tests at home (and get accurate time to loss-of-signal, if I can
duplicate the problem.
Regards,
David
Just flashed my 1.1 TeleMetrum and 0.2 TeleDongle to 1.2.1 firmware and noticed a couple of things. I think it was at 1.1 before.
Before the flash, it would allow me to connect even with a different call sign, now it is requiring a match. Also before the flash, the RSSI level was running at 0 with the units sitting within a couple of feet of each other, after the flash the RSSI went to -118. At the moment with the two units about 30 feet apart, I’m seeing -114 (assuming it is dB). I’m pretty sure the call sign thing is due to the new firmware but I’m surprised to see such a low signal strength reading. Was this worked on in the last couple of firmware changes?
Another question, there is an Apogee Lockout setting that is not in the current manual – is this a Mach lockout setting?
Hope to get another good workout for the TeleMetrum at our Sullivan Lake 20th Anniversary Launch this weekend.
Thanks for any help,
Eric
I just charged my TeleMetrum battery and I noticed that the
battery (silver wrapper) is bulging.
How bad is this?
It seems to be "working" and the TeleMetrum can talk to my
laptop. The software reports the battery voltage at 4.46 volts.
Is this a "normal" voltage for after a charge?
I too have lost the signal from a rocket once it has landed even when the rocket was in plain sight. I had no idea what was going on and thought that the battery or something had become disconnected. As I drove out of the parking lot to retrieve the rocket, I immediately began picking up the transmitter. After thinking about the rocket position, I believe that the problem was antenna orientation. From my viewing position the rocket was pointing away from me such that the antenna was perpendicular to plane of my antenna. By driving out of the parking lot, the orientation (plane) of the antenna changed and was now parallel to my yagi. Not surprising, I now had a full quieting signal.
Antennas don't propagate signals end-fire very well. Sometimes it pays to change your listening position when looking for a rocket after landing. For the most part antennas are not isotropic radiators.
Great seeing everyone at A.I.R. Fest.
Craig
DE K4LSU
Bdale and I tested a pile of stuff at Airfest last weekend and I wrote
up a report on my blog:
http://keithp.com/blogs/Airfest-altimeter-testing/
In brief:
TeleMega looks great! We're working to have this for sale by the end of
October:
http://altusmetrum.org/TeleMega/
TeleMetrum version 2 is working well, but GPS reception isn't what we
want. Bdale has a pile of new RF testing gear which should help sort
this out:
http://altusmetrum.org/TeleMetrum/
TeleMini v2 needs more firmware work, but the basic hardware is running:
http://altusmetrum.org/TeleMini/
EasyMini v1 saw a bunch more flights and we're going to hand-assemble a
small batch in the next few weeks to see how many people want them:
http://altusmetrum.org/EasyMini/
TeleGPS has the same GPS reception issues as TeleMetrum, and the
firmware isn't quite finished:
http://altusmetrum.org/TeleGPS/
-keith
Hello all.
Finally got around to giving my Telemetrum its maiden flight. I would like
to say everything went well, but it did not. The dangers of using older
motors.
Even worse, I have not been able to recover the rocket.
Based on the data file attached, I believe that the ejection charge did not
fire and the rocket came down ballistic. I also believe that the last
reported GPS co-ordinates were obtained shortly before impact, so you would
expect that I would have been able to find it.
I end up manually parsing the last lines of the file, and somehow came up
with a different set of GPS co-ordinates than were outputted by AltOSui. I
am not sure if this is due to an issue with my parser.
Does anyone mind having a look at the attached file and provide any
insights into where it may be, as it's is practically impossible to get
another right now. Best wishes to the operators with their rebuild.
Thank you for your time,
Anthony Kremor
