MicroPeak Question: Lowest recorded altitude?

[mh9162013]

I have a MicroPeak coming my way and I'm looking forward to using it. But I know that unless the rocket hits "about 30 m in height" it won't record the apogee.

So my question is: what's the lowest valid altitude reading you've ever recorded with your MicroPeak? I understand that w/e reading you get will, depending on conditions, needs to be adjusted for temperature. But ignoring that for a moment, what's the lowset altitude the MicroPeak can consistently measure?

I ask b/c some of my launches only get to 75-95 feet (like putting a 1/2A mini engine into a BT-50 rocket), and when I log the flight, I'd like to have a better idea of whether the MicroPeak malfunctioned or if I just didn't exceed the required altitude threshold.

EDIT: If it makes a difference, I don't have the USB dongle, so I won't have access to raw barometric data.

 

[Gus]

Once you reset the MicroPeak and place it in the rocket, it will not record any altitude unless it reaches it's minimum. So if you get a reading at all, it should be accurate-ish.

Other micro-altimeters, like the adrel, allow you to set the minimum altitude lower.

Steve

 

[mh9162013]

Once you reset the MicroPeak and place it in the rocket, it will not record any altitude unless it reaches it's minimum. So if you get a reading at all, it should be accurate-ish.

Other micro-altimeters, like the adrel, allow you to set the minimum altitude lower.

Steve

But what is this minimum? The instructions gave an estimate and I'm curious as to the actual value, at least from a programming perspective.

 

[mikec]

Looking at the source code, the Micropeak detects launch when the pressure goes down by 360 pascals, which corresponds to 30 meters at sea level or 36 meters at 2000 meters (according to the comments.)

http://git.gag.com/?p=fw/altos;a=snapshot;h=refs/tags/1.9.11;sf=tgz
30 meters is about 100 feet, so I wouldn't expect a flight lower than that to be logged.

 

[mh9162013]

Looking at the source code, the Micropeak detects launch when the pressure goes down by 360 pascals, which corresponds to 30 meters at sea level or 36 meters at 2000 meters (according to the comments.)

http://git.gag.com/?p=fw/altos;a=snapshot;h=refs/tags/1.9.11;sf=tgz
30 meters is about 100 feet, so I wouldn't expect a flight lower than that to be logged.

Thanks!

 

[mh9162013]

Looking at the source code, the Micropeak detects launch when the pressure goes down by 360 pascals, which corresponds to 30 meters at sea level or 36 meters at 2000 meters (according to the comments.)

http://git.gag.com/?p=fw/altos;a=snapshot;h=refs/tags/1.9.11;sf=tgz
30 meters is about 100 feet, so I wouldn't expect a flight lower than that to be logged.

How can I view the source code? Do I need some sort of program/app installed in my computer to do so?

 

[mikec]

The link goes to a compressed tar file ("tarball") that has all the files in it. You download it and then extract all the files and look at it with whatever. You need some program that can read the tarball (on Linux that program is called tar, I'm sure there are programs for Windows but I don't use it.)

And you get the files for everything AM makes, so it can be a challenge to find anything specific. It's a maze of different files and libraries with tons of conditional compilation to adapt to specific boards.

 

[mh9162013]

The link goes to a compressed tar file ("tarball") that has all the files in it. You download it and then extract all the files and look at it with whatever.

When I click on the link, nothing happens. I can understand if it automatically downloads, but the file is not recognized by my computer, but that's not happening here. Maybe I need to download the "reader" first, before downloading it?

 

[mikec]

Sorry, if you're using Windows, I can't help you.

If you go directly to https://git.gag.com/ and follow the tree links like https://git.gag.com/?p=fw/altos;a=tree you can browse the source online, but it's extremely hard to find anything in the maze of how they set it up. For example, the stuff in "micropeak" is all for the Java ground code, not for the code that runs on the device itself.

 

[mh9162013]

Sorry, if you're using Windows, I can't help you.

If you go directly to https://git.gag.com/ and follow the tree links like https://git.gag.com/?p=fw/altos;a=tree you can browse the source online, but it's extremely hard to find anything in the maze of how they set it up. For example, the stuff in "micropeak" is all for the Java ground code, not for the code that runs on the device itself.

I'll take a look at that site, thanks!