- pacsat-dev - mailman.amsat.org

Resolution - An Ax5043 is partially working on a Launchpad board (Issue #39)
by Jim McCullers 17 Jul '24

17 Jul '24

See attached.

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Re: Next meeting is July 18.
by Fevig, Ronald 15 Jul '24

15 Jul '24

Hi Bill, I am not certain I can attend the July 18 meeting. I will be in Albuquerque involved in University Nanosatellite Program PI activities. I spoke to my student team today about the possibility of having one of them attend in my absence. If I cannot attend, would it be appropriate for me to send a UND student representative? 73 Ron N0UCV From: bill via pacsat-dev <pacsat-dev(a)amsat.org> Sent: Thursday, July 4, 2024 1:27 PM To: pacsat-dev(a)amsat.org Subject: [pacsat-dev] Next meeting is July 18. Sent from my Boost Samsung Galaxy A32 5G

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Next meeting is July 18.
by bill 04 Jul '24

04 Jul '24

Sent from my Boost Samsung Galaxy A32 5G

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Re: Pacsat dev mtg 6/27/2024
by Fevig, Ronald 28 Jun '24

28 Jun '24

Hello Bill, I apologize to you and the Pacsat group. I somehow forgot we had a meeting last night. I'll blame it on my mind getting too cluttered due to a very busy week. I now set a weekly alarm on my cell phone to remind me of our Thursday evening meetings. By the way, we flew a high-altitude balloon last Wednesday, June 26. The payload, a VHF/UHF cross-band repeater, ascended to almost 97,000' and landed in a heavily wooded area. We are still figuring out how to retrieve it. Repeater functionality was passable, but certainly not optimal. A picture of the students and balloon moments before launch is attached. 73 Ron N0UCV -----Original Message----- From: Bill via pacsat-dev <pacsat-dev(a)amsat.org> Sent: Thursday, June 27, 2024 1:27 PM To: pacsat-dev(a)amsat.org Subject: [pacsat-dev] Pacsat dev mtg 6/27/2024 Pacsat dev mtg 6/27/2024 Thu, Jun 27, 2024 7:00 PM - 9:00 PM (CDT) Please join my meeting from your computer, tablet or smartphone. https://meet.goto.com/596395037 You can also dial in using your phone. (For supported devices, tap a one-touch number below to join instantly.) United States: +1 (312) 757-3121 - One-touch: tel:+13127573121,,596395037# Access Code: 596-395-037 Join from a video-conferencing room or system. Dial in or type: 67.217.95.2 or inroomlink.goto.com Meeting ID: 596 395 037 Or dial directly: 596395037(a)67.217.95.2 or 67.217.95.2##596395037 Get the app now and be ready when your first meeting starts: https://meet.goto.com/install ----------------------------------------------------------- pacsat-dev mailing list -- pacsat-dev(a)amsat.org View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/pacsat-dev@amsat.org To unsubscribe send an email to pacsat-dev-leave(a)amsat.org Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org

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Pacsat dev mtg 6/27/2024
by Bill 27 Jun '24

27 Jun '24

Pacsat dev mtg 6/27/2024 Thu, Jun 27, 2024 7:00 PM - 9:00 PM (CDT) Please join my meeting from your computer, tablet or smartphone. https://meet.goto.com/596395037 You can also dial in using your phone. (For supported devices, tap a one-touch number below to join instantly.) United States: +1 (312) 757-3121 - One-touch: tel:+13127573121,,596395037# Access Code: 596-395-037 Join from a video-conferencing room or system. Dial in or type: 67.217.95.2 or inroomlink.goto.com Meeting ID: 596 395 037 Or dial directly: 596395037(a)67.217.95.2 or 67.217.95.2##596395037 Get the app now and be ready when your first meeting starts: https://meet.goto.com/install

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Re: Pacsat dev mtg 6/20/2024
by Corey Minyard 20 Jun '24

20 Jun '24

Something just came up, I will not be able to make the meeting tonight. -corey On Thu, Jun 20, 2024 at 2:06 PM Bill via pacsat-dev <pacsat-dev(a)amsat.org> wrote: > > Pacsat dev mtg 6/20/2024 > Thu, Jun 20, 2024 7:00 PM - 9:00 PM (CDT) > > Please join my meeting from your computer, tablet or smartphone. > > https://meet.goto.com/345193165 > > You can also dial in using your phone. > (For supported devices, tap a one-touch number below to join instantly.) > > United States: +1 (571) 317-3122 > - One-touch: tel:+15713173122,,345193165# > > Access Code: 345-193-165 > > Join from a video-conferencing room or system. > Dial in or type: 67.217.95.2 or inroomlink.goto.com > Meeting ID: 345 193 165 > Or dial directly: 345193165(a)67.217.95.2 or 67.217.95.2##345193165 > > > Get the app now and be ready when your first meeting starts: > https://meet.goto.com/install > > > > ----------------------------------------------------------- > > pacsat-dev mailing list -- pacsat-dev(a)amsat.org > View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/pacsat-dev@amsat.org > To unsubscribe send an email to pacsat-dev-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org

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Pacsat dev mtg 6/20/2024
by Bill 20 Jun '24

20 Jun '24

Pacsat dev mtg 6/20/2024 Thu, Jun 20, 2024 7:00 PM - 9:00 PM (CDT) Please join my meeting from your computer, tablet or smartphone. https://meet.goto.com/345193165 You can also dial in using your phone. (For supported devices, tap a one-touch number below to join instantly.) United States: +1 (571) 317-3122 - One-touch: tel:+15713173122,,345193165# Access Code: 345-193-165 Join from a video-conferencing room or system. Dial in or type: 67.217.95.2 or inroomlink.goto.com Meeting ID: 345 193 165 Or dial directly: 345193165(a)67.217.95.2 or 67.217.95.2##345193165 Get the app now and be ready when your first meeting starts: https://meet.goto.com/install

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Re: Cursory look at compression on Pacsat
by Chris Thompson 18 Jun '24

18 Jun '24

I think that looks really useful. Especially given someone else already did a Java port. I think we would use this at the file level, reading from an uncompressed file and creating a compressed one. 73 Chris On Tue, Jun 18, 2024 at 2:03 PM Corey Minyard via pacsat-dev < pacsat-dev(a)amsat.org> wrote: > The most popular library seems to be heatshrink, at > https://github.com/atomicobject/heatshrink. There is a Java > implementation at https://github.com/markrileybot/heatshrink-java/ > > However, the C implementation hasn't been updated in 9 years. Not sure > what to make of that. It has a moderate number of issues. But it still > seems to be very popular. > > Tons of other libraries are available, but this seems the most used. > > -corey > > On Tue, Jun 18, 2024 at 11:13 AM Chris Thompson via pacsat-dev > <pacsat-dev(a)amsat.org> wrote: > > > > I think this is worth pursuing. If it's a simple algorithm then we > could port to java. Or have a standalone C executable that the ground > station runs. > > > > This would mainly be to compress logs, experiment data or telemetry > before it is downloaded. Uploading compressed data that the spacecraft can > uncompress is a separate use case if we want patch configuration or code. > > > > In a third seperate use case we can already compress large files and > upload them for later download. The spacecraft just treats them as binary > data and the ground stations do all the work. > > > > 73 > > Chris > > > > On Sun, Jun 16, 2024, 18:39 Corey Minyard via pacsat-dev < > pacsat-dev(a)amsat.org> wrote: > >> > >> I spent some time looking at implementations of compression > >> algorithms. As Bob pointed out, memory can be an issue with these > >> libraries. I was hoping to say that zlib (gzip) would be suitable, > >> but its minimum memory requirement appears to be 128K. There appears > >> to be a way to reduce that, but it's still probably going to be too > >> big. Later, better algorithms like bzip are going to be even more > >> memory intensive. > >> > >> I searched around and there are a large number of compression > >> libraries that are free and designed for microcontrollers, with memory > >> requirements in the hundreds of bytes (or even less!). None are as > >> good as even zlib, but they are better than LZW (compress) and would > >> be adequate. Also, more critically, they are designed to compress > >> small amounts of data efficiently. The trouble then becomes finding > >> one with a Java implementation, if we are planning to send the > >> compressed data over the download or uplink. > >> > >> Is this something worth pursuing? > >> > >> -corey - AE5KM > >> > >> ----------------------------------------------------------- > >> > >> pacsat-dev mailing list -- pacsat-dev(a)amsat.org > >> View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/pacsat-dev@amsat.org > >> To unsubscribe send an email to pacsat-dev-leave(a)amsat.org > >> Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org > > > > > > ----------------------------------------------------------- > > > > pacsat-dev mailing list -- pacsat-dev(a)amsat.org > > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/pacsat-dev@amsat.org > > To unsubscribe send an email to pacsat-dev-leave(a)amsat.org > > Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org > > ----------------------------------------------------------- > > pacsat-dev mailing list -- pacsat-dev(a)amsat.org > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/pacsat-dev@amsat.org > To unsubscribe send an email to pacsat-dev-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org > -- Chris E. Thompson chrisethompson(a)gmail.com g0kla(a)arrl.net

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Re: Cursory look at compression on Pacsat
by Corey Minyard 18 Jun '24

18 Jun '24

The most popular library seems to be heatshrink, at https://github.com/atomicobject/heatshrink. There is a Java implementation at https://github.com/markrileybot/heatshrink-java/ However, the C implementation hasn't been updated in 9 years. Not sure what to make of that. It has a moderate number of issues. But it still seems to be very popular. Tons of other libraries are available, but this seems the most used. -corey On Tue, Jun 18, 2024 at 11:13 AM Chris Thompson via pacsat-dev <pacsat-dev(a)amsat.org> wrote: > > I think this is worth pursuing. If it's a simple algorithm then we could port to java. Or have a standalone C executable that the ground station runs. > > This would mainly be to compress logs, experiment data or telemetry before it is downloaded. Uploading compressed data that the spacecraft can uncompress is a separate use case if we want patch configuration or code. > > In a third seperate use case we can already compress large files and upload them for later download. The spacecraft just treats them as binary data and the ground stations do all the work. > > 73 > Chris > > On Sun, Jun 16, 2024, 18:39 Corey Minyard via pacsat-dev <pacsat-dev(a)amsat.org> wrote: >> >> I spent some time looking at implementations of compression >> algorithms. As Bob pointed out, memory can be an issue with these >> libraries. I was hoping to say that zlib (gzip) would be suitable, >> but its minimum memory requirement appears to be 128K. There appears >> to be a way to reduce that, but it's still probably going to be too >> big. Later, better algorithms like bzip are going to be even more >> memory intensive. >> >> I searched around and there are a large number of compression >> libraries that are free and designed for microcontrollers, with memory >> requirements in the hundreds of bytes (or even less!). None are as >> good as even zlib, but they are better than LZW (compress) and would >> be adequate. Also, more critically, they are designed to compress >> small amounts of data efficiently. The trouble then becomes finding >> one with a Java implementation, if we are planning to send the >> compressed data over the download or uplink. >> >> Is this something worth pursuing? >> >> -corey - AE5KM >> >> ----------------------------------------------------------- >> >> pacsat-dev mailing list -- pacsat-dev(a)amsat.org >> View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/pacsat-dev@amsat.org >> To unsubscribe send an email to pacsat-dev-leave(a)amsat.org >> Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org > > > ----------------------------------------------------------- > > pacsat-dev mailing list -- pacsat-dev(a)amsat.org > View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/pacsat-dev@amsat.org > To unsubscribe send an email to pacsat-dev-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org

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Re: Cursory look at compression on Pacsat
by Chris Thompson 18 Jun '24

18 Jun '24

I think this is worth pursuing. If it's a simple algorithm then we could port to java. Or have a standalone C executable that the ground station runs. This would mainly be to compress logs, experiment data or telemetry before it is downloaded. Uploading compressed data that the spacecraft can uncompress is a separate use case if we want patch configuration or code. In a third seperate use case we can already compress large files and upload them for later download. The spacecraft just treats them as binary data and the ground stations do all the work. 73 Chris On Sun, Jun 16, 2024, 18:39 Corey Minyard via pacsat-dev < pacsat-dev(a)amsat.org> wrote: > I spent some time looking at implementations of compression > algorithms. As Bob pointed out, memory can be an issue with these > libraries. I was hoping to say that zlib (gzip) would be suitable, > but its minimum memory requirement appears to be 128K. There appears > to be a way to reduce that, but it's still probably going to be too > big. Later, better algorithms like bzip are going to be even more > memory intensive. > > I searched around and there are a large number of compression > libraries that are free and designed for microcontrollers, with memory > requirements in the hundreds of bytes (or even less!). None are as > good as even zlib, but they are better than LZW (compress) and would > be adequate. Also, more critically, they are designed to compress > small amounts of data efficiently. The trouble then becomes finding > one with a Java implementation, if we are planning to send the > compressed data over the download or uplink. > > Is this something worth pursuing? > > -corey - AE5KM > > ----------------------------------------------------------- > > pacsat-dev mailing list -- pacsat-dev(a)amsat.org > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/pacsat-dev@amsat.org > To unsubscribe send an email to pacsat-dev-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org >

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