Has anyone flown a Telemetrum or Telemega before and have the unit go silent (quit sending packets) right at apogee? It was communicating just fine until apogee, then went silent.
Mark
Mark
Telemetrum going silent at apogee
- Thread starter HyperSonic
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Interesting. Never had that happen to mine.
Have you got it back yet? I would query anything that might have removed power at apogee. They don't transmit for long after power is removed.
Big jolt from pyro, chute snap-loading, shorted igniter, battery retention failing, miswired terminal block.
Were you using only one battery for both power and pyros?
Have you got it back yet? I would query anything that might have removed power at apogee. They don't transmit for long after power is removed.
Big jolt from pyro, chute snap-loading, shorted igniter, battery retention failing, miswired terminal block.
Were you using only one battery for both power and pyros?
plugger
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Yes, I've had this occur twice with the TeleMetrum, v1.0 and 1.2 specifically. What hardware and version were you on?
My TeleMetrum 1.0 failure was due to the lipo protection circuit issue that was not very well communicated at the time. Full vehicle loss as a result.
https://altusmetrum.org/Documents/FixBattery/
The TeleMetrum 1.2 issue was a bit more strange. It stopped talking at apogee but both the apogee and main charges fired successfully. I was able to recover the rocket by wandering in the area I suspected it came down until I found it. I'd flown it before and since without issue.
Do you have any further details regarding your issues?
My TeleMetrum 1.0 failure was due to the lipo protection circuit issue that was not very well communicated at the time. Full vehicle loss as a result.
https://altusmetrum.org/Documents/FixBattery/
The TeleMetrum 1.2 issue was a bit more strange. It stopped talking at apogee but both the apogee and main charges fired successfully. I was able to recover the rocket by wandering in the area I suspected it came down until I found it. I'd flown it before and since without issue.
Do you have any further details regarding your issues?
Actually I think I just remembers something in a recent firmware upgrade that eliminated a bug where the telemetry would go silent. Something to do with the data logging maybe? Check the altusmetrum.org site.
Found it on their website:
If you are running later hardware/firmware you should not have this problem. I think this came out about 18 months ago? Not sure.
Found it on their website:
If you are running later hardware/firmware you should not have this problem. I think this came out about 18 months ago? Not sure.
About a year ago I launched a 2.6 inch airframe with a K270 long burn to a height of 11,000 feet with a Telemetrum V2.0 on board. This rocket has flown the last six flights without incident. Everything was communicating just fine until apogee, and things got quiet. No more packets coming in, and at 11K feet you cant see a 2.6 inch rocket. Never seen it come down. Lost
3 months later..........
I never gave up on this rocket as I had the last known position of rocket at 11K, I went back looking for it a few times, and about 3 months later I FOUND IT! It looked to be untouched by anyone laying in a field right next to a tree line. Upon initial inspection, I noticed the drouge had fired (thank god for that) but the main was still tucked away in the airframe with the shear pins still holding the nose cone on. It never fired the main, and came down on the drouge.
After getting it home (and a night of drinking to celebrate finding rocket!) I noticed a dent in the edge of my coupler sticking out of the booster section. This dent was not there before the launch. The rocket landed in soft dirt, so I dont think it was caused during the landing. I rang out the switch circuit and had continuity through the switch. This tells me that the contacts in the switch are still touching together. Then it dawned on me, the contacts Bounced during the collision between the booster and the upper airframe (dual deploy) causing a brown out to the processor right when the rocket was horizontal (making its turn for home) How many milliseconds of interrupted power would it take for the processor to shut down, or try to reset itself. Either way at that point the telemetrum is just along for the ride.
I dont know if the telemetrum V2.0 has a capacitor on board like the Raven 3, to help prevent against a brown out condition. Keep the processor running for several seconds should power be interrupted for any reason.
I took apart the switch to see for my own eyes what makes it tick. This was a 2 position slide switch made in taiwan that I got many years ago from PML. The spring inside the switch (holds two thin pieces of metal together to make circuit) is so tiny, that it would not take much shock to cause things to start bouncing. This along with no brown out capacitor on board, is my theory of what happened in my case. I dont know for a fact that Telemetrum V2.0 has a cap on board for this reason. A simple question to the designers would clear that part up.
It never dawned on me to look at firmware version. Still has same firmware as when I bought it years ago.
Mark
3 months later..........
I never gave up on this rocket as I had the last known position of rocket at 11K, I went back looking for it a few times, and about 3 months later I FOUND IT! It looked to be untouched by anyone laying in a field right next to a tree line. Upon initial inspection, I noticed the drouge had fired (thank god for that) but the main was still tucked away in the airframe with the shear pins still holding the nose cone on. It never fired the main, and came down on the drouge.
After getting it home (and a night of drinking to celebrate finding rocket!) I noticed a dent in the edge of my coupler sticking out of the booster section. This dent was not there before the launch. The rocket landed in soft dirt, so I dont think it was caused during the landing. I rang out the switch circuit and had continuity through the switch. This tells me that the contacts in the switch are still touching together. Then it dawned on me, the contacts Bounced during the collision between the booster and the upper airframe (dual deploy) causing a brown out to the processor right when the rocket was horizontal (making its turn for home) How many milliseconds of interrupted power would it take for the processor to shut down, or try to reset itself. Either way at that point the telemetrum is just along for the ride.
I dont know if the telemetrum V2.0 has a capacitor on board like the Raven 3, to help prevent against a brown out condition. Keep the processor running for several seconds should power be interrupted for any reason.
I took apart the switch to see for my own eyes what makes it tick. This was a 2 position slide switch made in taiwan that I got many years ago from PML. The spring inside the switch (holds two thin pieces of metal together to make circuit) is so tiny, that it would not take much shock to cause things to start bouncing. This along with no brown out capacitor on board, is my theory of what happened in my case. I dont know for a fact that Telemetrum V2.0 has a cap on board for this reason. A simple question to the designers would clear that part up.
It never dawned on me to look at firmware version. Still has same firmware as when I bought it years ago.
Mark
You need a seriously big cap to keep transmitting for any significant amount of time. I fitted a 1F cap because it is what I have lying around. It would help for momentary dropouts but not much else.
Yes I agree with the physical size of cap. I dont see one on my telemetrum V2.0. That is why I dont think they have one on the board. Do you think the protection circuit on the lipo battery itself has something to do with shutting down the power, because it (the protection circuit) thought high current or over voltage was going on? Im using separate batterys for pyro and altimeter power. I never removed the protection circuit on any of my lipos. And I have flown the telemetrum or mega a total of 9 different times, without problems. I very much like the products from AltusMetrum. I need to stay up with the firmware updates and such. But when things are working correctly, why look for problems.
Mark
Sorry for your total loss of rocket and everything on board. I never knew about the protection circuit causing a problem until you said something. My telemetrum and telemega have both been working fine except for this freak incident. And the protection circuits are still on my lipos. I think I better remove them before something else happens. I think a combination of shock (bouncing contacts) and the protection circuit not removed combined for my issue. If I only knew for sure!
Mark
plugger
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Situations like this are part of the many reasons why I no longer use Altus Metrum products for deployment duties (other than the TeleMini). I'm a huge fan of the TeleGPS but I've had enough "head scratching" experiences with other Altus Metrum products that combine deployment and tracking to steer clear of them.
I have not had any anomalous behaviour from the TeleMegas I own.
I do run a separate battery for power and for the eMatches.
I would be very wary of protection circuits on LiPos, and have heard of people that have had them trip out and cause problems. That's why I use separate batts for deloyment.
I do run a separate battery for power and for the eMatches.
I would be very wary of protection circuits on LiPos, and have heard of people that have had them trip out and cause problems. That's why I use separate batts for deloyment.
plugger
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I don't nor have ever owned a TeleMega so I can't pass judgement on them specifically. But I've helped multiple people (THUNDA for instance) with comms issues regarding connecting their TeleMetrums to their Laptops. My solution has always been to shut down everything and try again. It's frustrating that works, but it does.
That's a feature specific to the *Mega family.
After the total loss of my first Blackhawk 38 and TeleMetrum 1.0 I'd have to agree with you there.
This is a learning experience for me.
1. If you like to fly high as I do and want to find your rocket the same day that you launched it, you better have more than one tracking system on board. (I should already know this!)
2. I use screw switches now. Better for shock on a rough and physical flight. They can still back out, but if you tighten them enough, you will be OK
3. Remove protection circuit from lipo's
4. Download newer version of firmware
Thank you for sharing your experience with the Tele family. I usually have the TeleMega paired up with a Raven 3 for backup. I run THREE totally separate tracking systems. (TeleMega is one)
If I lost a rocket that cost me hundreds of dollars and months of my time to build because of altimeter problems, I would reconsider my choices for the future.
For me, I plan on pushing my TeleMega to 40K one day, with backup of course!
Mark
1. If you like to fly high as I do and want to find your rocket the same day that you launched it, you better have more than one tracking system on board. (I should already know this!)
2. I use screw switches now. Better for shock on a rough and physical flight. They can still back out, but if you tighten them enough, you will be OK
3. Remove protection circuit from lipo's
4. Download newer version of firmware
Thank you for sharing your experience with the Tele family. I usually have the TeleMega paired up with a Raven 3 for backup. I run THREE totally separate tracking systems. (TeleMega is one)
If I lost a rocket that cost me hundreds of dollars and months of my time to build because of altimeter problems, I would reconsider my choices for the future.
For me, I plan on pushing my TeleMega to 40K one day, with backup of course!
Mark
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