Project ALTDuino - A homemade altimeter

Yoehahn said:

Ill be interested to see what you come up with. I already modified one to make it MD, dual deploy, and have a timer to light the sustainer. its crazy hard! good luck.

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That's fantastic! Please show some pictures of your Elliptic and the electronics used.

My version will be straight forward; Small e-bay in the upper section of the rocket with break away and main streamer recovery.

Leo said:

The Teensy is also a very nice alternativ. It has a reset button which I will be needing later on in the development.

Teensy website

I do plan on releasing the software at some point and time but I still have a lot of work to do to make it user friendly.

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Great news. I've been following your project page. Great results and great write up.

I have written a setup window so that the altimeter can now be configured conveniently from within the UI.



I'd like some comments on the main deployment altitude heights. Are the available selections satisfactory for mid and high powered flights?

Those look similar to what my Adept22 provides. I'd say that's good. Is there any reason you can't have it be a user-entered number?

Also, This may be premature but how does one set the points where the other pyro channels fire?

Looks great to me.

Thanks guys.

"Is there any reason you can't have it be a user-entered number?"

I want to make it safe and simple for now. Analyzing faults with fixed parameters makes it a little easier for me for now.


I don't quite understand what you mean by "how does one set the points where the other pyro channels fire?" Could you please elaborate.

Essentially, does the user have control over when the Sustainer Firing and Auxiliary Pyro channels fire?

I should have said before, looks GREAT! This thing really tickles my fancy. The Software just makes it that much better.

Thanks.

The sustainer ignition is done at thrust cut-off. No other options are available and as far as I can determine are needed. E.g. I can't see putting in a delay of any use.

The "Optional channel" is undefined. Many options available but I have no idea what I could use it for atm.

A delay is useful to keep the speed down and maximize altitude.

That is very interesting. I had always thought that stage ignition should occur at maximum acceleration cut-off for maximum altitude.

What kind of delays are we talking about? 0.5 sec, 1 sec or more in addition to the delay caused when the igniter is set off and till the time the rocket motor actually fires?

Really sweet project! I hope you'll keep us posted as you develop it.

Often, you want to go as slow as you can before lighting up the second stage, with the main limitation safety (due to possible instability). The savings in drag much more than make up for the reduction in kinetic energy extracted from the sustainer propellant by moving it faster before burning.

Depending on the burnout speed of the first stage, this might be 2 seconds, or it might be 10 seconds (!).

The Featherweight Raven lets you set a velocity threshold, as well as other conditions: light it once the integrated speed drops below xxx value, assuming it has reached yyy altitude and the time is greater than zzz. This lets you input simulation parameters that can help prevent sustainer ignition in the case of a non-nominal flight (weathercocking, instability).

Leo said:

I have written a setup window so that the altimeter can now be configured conveniently from within the UI.

I'd like some comments on the main deployment altitude heights. Are the available selections satisfactory for mid and high powered flights?

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All the easy stuff covered, lets tackle those annoying spiral grooves in the body tube now.:bangpan:

SPECTACULAR work Dude! Thank you for sharing.

CarVac said:

Often, you want to go as slow as you can before lighting up the second stage, with the main limitation safety (due to possible instability). The savings in drag much more than make up for the reduction in kinetic energy extracted from the sustainer propellant by moving it faster before burning.

Depending on the burnout speed of the first stage, this might be 2 seconds, or it might be 10 seconds (!).

The Featherweight Raven lets you set a velocity threshold, as well as other conditions: light it once the integrated speed drops below xxx value, assuming it has reached yyy altitude and the time is greater than zzz. This lets you input simulation parameters that can help prevent sustainer ignition in the case of a non-nominal flight (weathercocking, instability).

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Extremely interesting! Something I will have to look into at a later date and it should be fun experimenting with aswell! Thank you.

Scott Evil said:

All the easy stuff covered, lets tackle those annoying spiral grooves in the body tube now.:bangpan:

SPECTACULAR work Dude! Thank you for sharing.

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Thanks.

If you're referring to my rocket, the Estes Mongoose, well... it comes prefabricated like that.

However, I'm near completion of a new rocket that I will be using for ongoing altimeter flight tests. You should be happy with the finish on that one (will post it here)

I love where this is going! I have an Arduino, and have often wondered about making it into my own altimeter. When I get around to it I figured I would fly it as a data recorder only with another altimeter to fire the charges until I was satisfied that it was working properly.

Keep up the good work!!

Leo,
I'm very impressed with your work, thanks for sharing that with us. What's equally amazing is the fact that you are still flying the same rocket since 1981!

Thanks guys.

Flying my altimeter on it's maiden voyage with my '81 Estes Icarus made it even more special

CarVac,

Because of you I did some programming and it's now possible to select the velocity to the point at which the sustainer should be ignited. The setting "Max" means sustainer ignition is at max velocity. It should be fun experimenting with this feature.

Pyro 1 and Pyro 2 delays can now be changed in 1 second intervals.

A quick post to show my new ALTDuino altimeter carrier rocket

I call it ALTDuino-Rocks!



All it needs is some decals. Gordy will get an order soon

Very good work, Leo!
I too am interested in the software you have developed. I am interested in building Arduino devices for rocketry and radio control models.
I have used Arduino boards to build motion control devices for machining. The tough part for me has always been the software.

I have updated the rocket picture as it is now blessed with decals

Sometimes a build just doesn't want to come together. Building the lower (black) portion of this rocket has been a nightmare. Starting with an uneven body tube that needed a lot of sanding, white glue warping the body tube, primer that just didn't want to fill the holes as I had liked it to.
To compound everything I had to find out that paint and soap doesn't mix! What happened was that after I gave the rocket it's first black paint job I wet sanded it to get rid of the last blemishes.
When done I cleaned my hands with soap to get the black paint residue of them. Then I cleaned up the rocket unknowingly contaminating it with leftover soap that was still on my hands. When I put on the second black coat of paint I had huge craters all over. That meant I had to sand down the rocket to it's first black coat and redo the second layer. Even that wasn't picture perfect. Since I already had so many coats on the rocket I let it be. And to top it off the top portion of the body tube is starting to show cracks in the paint, something that never has had happen to me before.

Nonetheless, I think it still looks great and I can't wait for it's maiden flight.

Looks Great Leo.

One problem. I hope you don't need more decals 'cause i just cannot find the file I drew...:blush:

I'll keep looking. I'm sure it's somewhere on my computer.

Gordon, I don't understand. I drew up the decals and sent them to you as pdf file for you to print out.

If I need more I can always send you the pdf file again.

Leo I've got a couple of well powered hybrid taxis for your altimeter...any chances?

Leo, Oh I have them.

With decal file topping over 600 separate files I just don't know where I put them.:blush:

They are here someplace.

I'll find them.

Leo said:

Gordon, I don't understand. I drew up the decals and sent them to you as pdf file for you to print out.

If I need more I can always send you the pdf file again.

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I didn't mean to scare you.

I found it.

It got put into the wrong folder is all.

Today was the maiden flight of the ALTDuino-Rocks! including further developed firmware.



It flew straight and high



Of course the nose cone wasn't tight enough and the main parachute opened up prematurely. I guess I'll never learn

Nice work Leo!

Are the graphics something that you created for the data? If so, it is one of the best representation of the data I've seen.

Greg

Thanks Greg.

Yes, I created the program specifically for the altimeter data.