Beeping Altimeters

[cerving]

Just what it says... which beeps do you really need to hear when you power on your altimeter? Remember, each value adds about 15-20 seconds to the time that you have to wait before you can launch... so all three will probably add a minute to your power-to-launch time.

This is for our upcoming dual-deploy rocket/altimeter kit... seeing how thin or fat the firmware is going to have to be. Of course, if there's a continuity problem it's going to beep out the offending channel and not arm, and if everything is OK you'll get the familiar Eggtimer "I'm armed" chirping. That's why continuity/ready isn't in the poll.

If you can think of another one, let me know that too. Thanks!

Cris Erving
Eggtimer Rocketry

 

[mbeels]

My vote would be either just a "continuity good, self check ok" beep, or that plus battery voltage. I think no need for last apogee or max velocity.

 

[jhornsby3]

How about the "cha ching" sound of a cash register? For obvious reasons.

 

[cerving]

My vote would be either just a "continuity good, self check ok" beep, or that plus battery voltage. I think no need for last apogee or max velocity.

OH, you're going to get "a no-continuity" beep regardless... and the usual Eggtimer "I'm armed!" chirping too. I'll edit the original text.

 

[Charles_McG]

Is this a Wifi connected device?

 

[cerving]

No, it's a traditional dual-deploy altimeter with a built-in electronic push-button switch... operationally similar to the Quark. Uses a 9V battery (6LR61-type recommended). It draws < 10 uA when "OFF", so you can store it with the battery connected for awhile... with the energetics removed, of course.

 

[mbeels]

operationally similar to the Quark.

Ah, that makes a difference. In that case I'd like to have last altitude. Especially if it isn't a logging altimeter with data download.

 

[SolarYellow]

I'd vote for last apogee as well. I reckon I should be checking voltage with a DMM before powering it on if I have any doubt.

 

[Joel Shepherd]

If there’s a possibility of distinguishing between a long and short push, a “ready” (or not) chirp on a short push to power on, and last max altitude on a long push would be nice. Too much chirping before launch is distracting.

 

[Aeva]

Battery voltage seems like something you'd want to alert after the initial boot. Like, rather than only checking the battery voltage on start, periodically check it with each loop, and if it drops below the desirable threshold, start the buzzer with an "alarming chirp". I think last apogee and last max velocity would be the information best "beeped" at start because that's usually what people like to record.

 

[fyrwrxz]

Cris, whatever you call it, and however it beeps, I'll take one. Serial No. 0002 is fine!

 

[cbrarick]

can you make it beep out the star spangled banner?
or the horse racing call to post?

 

[Aeva]

can you make it beep out the star spangled banner?
or the horse racing call to post?

when it gets stuck in a tree it does a sad trombone sound...

 

[Voyager1]

Other than the power on beeps, for a dual deployment altimeter, I generally prefer to hear the 1, 2 or 3 beeps to confirm drogue, main, drogue+main continuity, preferably with pitch control for multiple altimeters.

 

[conneryc]

Since it should be beeping out the altitude after the flight, I wouldn't want to have to wait for it to do that again after I turned it back on. IMHO, if I'm going to use a barebones altimeter, I'm not really worried about how high it went or how fast it went, but telling me the current battery voltage just to confirm that I didn't forget to charge the battery would be nice.

That being said, I've gotten used to the wireless connectivity (and tracking) of the Quasar that I've been using, so I doubt I'll ever use a non-wireless altimeter as my primary in the future.

 

[Neutronium95]

The altimeters I most commonly use are Stratologgers and EasyMinis. The Stratologger startup sequence is quite long since it tells you so much information, including the main deployment altitude, if it has an apogee delay, the previous apogee, battery voltage, and finally charge continuity. It's somewhat annoying, since it takes a while, but for the most part I appreciate the information. The EasyMini just beeps out the battery voltage before going into continuity beeps.

I'd like to know information relevant to the flight I'm arming an altimeter for. For me that would mean battery voltage, main deployment altitude, and apogee deployment delay.

 

[cerving]

So I think I've settled on only having the new altimeter beep out battery voltage, and deployment channel error codes if they're not good. That significantly shortens the power-on to flight-ready time... it was over 90 seconds beeping out the last altitude and last maximum velocity, along with the battery voltage. Apogee is going to get beeped out after landing anyway, so you can get it then. Also, it's going to send out telemetry, so if you add an Eggtimer Telemetry Module and LCD receiver you'll get real-time altitude, velocity, and flight status, plus apogee and maximum altitude after the drogue fires. All the data is there if you want it, and if you don't want it you're not going to be penalized by having to wait for an extra minute's worth of beeping.

 

[Tractionengines]

Sounds good. One question any way to add an Open Log Datalogger to record the Flight data to SD Card? (I know the Eggfinder logs the GPS data easily. Would be nice if the altimiters could do this too.)

It's fairly easy to parse a single text file into individual flights just a little sorting of data.

 

[mbeels]

Probably this adds complexity, but if you have extra I/O pins, what about an optional configuration that could be chosen at the time of building? Since it is a kit anyway, you could offer some combination of zero ohm resistors (or whatever) and allow the builder to choose.

 

[Kelly]

Since it should be beeping out the altitude after the flight, I wouldn't want to have to wait for it to do that again after I turned it back on.

The trouble is, if you had a power loss after apogee (maybe a brownout at deployment, or maybe you didn't find your rocket until after it had laid there a while and the battery died), then you've lost all data for the flight.
I prefer max alt. Everyone should have a battery checker handy and use it before buttoning up the device.

 

[Charles_McG]

The trouble is, if you had a power loss after apogee (maybe a brownout at deployment, or maybe you didn't find your rocket until after it had laid there a while and the battery died), then you've lost all data for the flight.
I prefer max alt. Everyone should have a battery checker handy and use it before buttoning up the device.

Also, OCV (open circuit voltage) is pretty flat vs % capacity for most batteries, and just running armed, the altimiter itself is likely a pretty light load. While I've -seen- the discharge curves for 9V (which varies by supplier) and for some Lipos - I certainly don't have them memorized.

That said - cold weather dings that voltage hard, and thhat reminder while setting up at the field might not be a bad reminder.

 

[Handeman]

So I think I've settled on only having the new altimeter beep out battery voltage, and deployment channel error codes if they're not good. That significantly shortens the power-on to flight-ready time... it was over 90 seconds beeping out the last altitude and last maximum velocity, along with the battery voltage. Apogee is going to get beeped out after landing anyway, so you can get it then. Also, it's going to send out telemetry, so if you add an Eggtimer Telemetry Module and LCD receiver you'll get real-time altitude, velocity, and flight status, plus apogee and maximum altitude after the drogue fires. All the data is there if you want it, and if you don't want it you're not going to be penalized by having to wait for an extra minute's worth of beeping.

Besides the battery voltage, having the last altitude beeped out is really nice. When walking back after recovering the rocket and hearing all the beeps from dual altimeters, its sometimes very hard to determine the altitude when two altimeters are beeping. It's really nice to be able to turn one off, get the altitude on the other, then turn the first one off and the second one on so I get the altitude from the second one.

If there is one altimeter, it's not a problem, but if you can't download data, having the previous altitude beep out at power up is almost essential if you are using two altimeters.