- pacsat-dev - mailman.amsat.org

Re: pacsat dev meeting 1-5-2023
by Chris Thompson 06 Jan '23

06 Jan '23

I'm unable to attend today. Sorry about the late notice. I hope to attend next time. 73 Chris On Thu, Jan 5, 2023, 15:21 Bill via pacsat-dev <pacsat-dev(a)amsat.org> wrote: > Welcome to 2023, see you at 7PM > > pacsat dev meeting 2023-1 > Thu, Jan 5, 2023 7:00 PM - 9:00 PM (CST) > > Please join my meeting from your computer, tablet or smartphone. > > https://meet.goto.com/444756509 > > You can also dial in using your phone. > (For supported devices, tap a one-touch number below to join instantly.) > > United States: +1 (408) 650-3123 > - One-touch: tel:+14086503123,,444756509# > > Access Code: 444-756-509 > > > 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 meeting 1-5-2023
by Bill 05 Jan '23

05 Jan '23

Welcome to 2023, see you at 7PM pacsat dev meeting 2023-1 Thu, Jan 5, 2023 7:00 PM - 9:00 PM (CST) Please join my meeting from your computer, tablet or smartphone. https://meet.goto.com/444756509 You can also dial in using your phone. (For supported devices, tap a one-touch number below to join instantly.) United States: +1 (408) 650-3123 - One-touch: tel:+14086503123,,444756509# Access Code: 444-756-509 Get the app now and be ready when your first meeting starts: https://meet.goto.com/install

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Satellite use of the AX5043
by Jim McCullers 04 Jan '23

04 Jan '23

Over the holiday break I did some Google searches on the use of the AX5043 in satellite service and found the following references. These two publications cover the OreSat developed at Portland State University. The Ax5043 is employed as UHF transceiver as well as IF for an L-Band receiver. As of yet, I have not received a signal from OreSat0 but as it is a telemetry only satellite the transmitter is possibly only activated for passes over the Oregon area. I've reached out to them via email but have yet to receive a response. https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=5110&context=smal lsat https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=6639 <https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=6639&context =open_access_etds> &context=open_access_etds This paper deals with detection of UHF uplink interference using the AX5042 similar to the AX5043 and makes an interesting case not to use 70cm uplinks due to interference caused by the shared services in the 70cm band. They used a single antenna and LNA into a 4-way splitter similar to what is planned for Pacsat. https://www.sciencedirect.com/science/article/pii/S0273117721007778 The final paper is an interesting study of the AX5043 capabilities. They examined the radiation resistance of the AX5043 and found it held up well. Also is an interesting discussion of LNA requirements as well as radiation resistance of various transistor types. It should be noted the original project was canceled and a follow on is due to launch in 2023. How it might vary in configuration is not published. https://core.ac.uk/download/pdf/295596877.pdf Jim McCullers WA4CWI

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Bug in TMS570 HALCoGen SPI Baudrate
by Burns Fisher (AMSAT) 19 Dec '22

19 Dec '22

One can't use HALCoGen to set the SPI baudrate. It always comes out to be VCLK1/40. So in the case of both the RTIHU and the Launchpad, this ends up being 2Mhz. It is reasonably easy to add code outside of that generated by HALCoGen, and I think there are fixes that we can make to HALCoGen in an XML file somewhere, although I have not tried it. Note that this bug was reported to TI 10 years ago and the response was that the bug would be fixed with a patch soon. Nope. I currently have the latest and greatest version (4.07.01) and it still has the problem. Note also that the way the driver on both PacSat and Golf-TEE works, it only makes a little difference for relatively small transfers. 73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software*

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Pacsat dev meeting #7
by Bill 15 Dec '22

15 Dec '22

Pacsat dev meeting #7 Thu, Dec 15, 2022 7:00 PM - 9:00 PM (CST) Please join my meeting from your computer, tablet or smartphone. https://meet.goto.com/134512253 You can also dial in using your phone. (For supported devices, tap a one-touch number below to join instantly.) United States: +1 (872) 240-3412 - One-touch: tel:+18722403412,,134512253# Access Code: 134-512-253 Get the app now and be ready when your first meeting starts: https://meet.goto.com/install Agenda: Burns will talk about his mram testing

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My Action Items
by Bob Stricklin 15 Dec '22

15 Dec '22

All, Attached is a Excel/PDF outlining the current needs of the Pacsat system. The is based on the previous Fox design concept with some adjustments to match our needs. This is a first pass and the best information will come from testing since this is a dynamic system. In the sheet I indicate the possible modes the TMS570 may operate in. I have not looked at the details of the two principal modes. The mode that requires the most current is the mode with Built In Self Test (BIST). After launch testing may not be useful to us as we will limited ability to correct for problems. The modes can be changed by changing register values. I can see a lot of development time may be needed to understand these modes and test the results of making any changes between modes. I would like to hear some comments regarding the earlier development for this device. We will want to know the impact of making any changes before firming up launch code packages. In the PGE package we can operate the TMS570 up to 160 MHz in the pipeline mode. We can also reduce the clock rate and obtain a savings of 0.85 mA for every 1 MHz reduction in clock rate. Most of the current consumed by this part is provided by the 1.2 Volt supply line. If we drop the clocking rate to 100 MHz we can realize a savings of 51 mA or about 61 mW. This clock rate reduction will be limited by the ability to collect and process the data from the radio modems and memory devices. Testing with software in place will probably be needed to get an idea of what is required. I am attaching a set of drawings for the first pass at a design for the AX5043 system. This includes 4 receivers and 1 transmitter. The transmitter is the same as the design used in the Fox program. The receivers are changed to to use a single antenna, filter with a bandwidth to cover the 2m operating band, preamp, and power divider. More work is needed on all this as well but I wanted to show some progress. There may be enough flexibility in the AX5043 chips channel selection to allow us to program four different receive frequencies while using a single reference oscillator. We may also need a clock reference generating system and I have started laying this into the design to be sure it is covered. I have not yet included in power requirements for these devices. Bob N5BRG

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Trying to write filesystem document
by Corey Minyard 15 Dec '22

15 Dec '22

I don't appear to have write access to AMSAT-NA/pacsat on github. Do you want to do this with clones and merges? -corey

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Summary of Pacsat basic software
by Burns Fisher (AMSAT) 14 Dec '22

14 Dec '22

The master branch will now work with 2 mrams as I said before. It also can successfully talk to a serial line at 32k8 (and you really have to have that to do anything useful) as well as an AX5043. I have managed to get the 5043 to see a carrier on 2m (the RSSI goes way up) but not to get it to decode anything or transmit anything. I may try that more, but I'm not the 5043 expert by far! After talking with Jim McCullers, I converted all the connections to use inner pins (Booster Pack connectors) rather than the outside pins. Here are all the connections that the software is setup to use. You can also use the equivalent pins on the outside of the Launchpad (J10 and J11) but I wanted to make sure it would work with the inner pins. (J2/3 means header J2, pin 3. Pins are counted from 1 on the USB connector end) Power out (to MRAM and AX5043 board) 3.3V Output J2/1 Gnd J5/1 Console serial line: Rx-J2/3 Tx-J2/4 Gnd-J3/2 (Or any other --there are lots) SPI1 (to both MRAMs): Note that the common term for the data lines is MISO and MOSI. TI calls them SOMI and SIMO, the MRAMs just call them SO and SI. MISO: J9/7 MOSI: J9/6 CLK: J67 NCS0: J9/3 (For MRAM 0) NCS1: J9/8 (For MRAM 1) SPI3 (for AX5043--probably for all if we have more than 1) MISO: J5/7 MOSI: J5/6 CLK: J2/7 NCS1 J5/3 (Additional 5043s could use other NCS pins on SPI3. IRQ goes to GIOB[0] J8/8 (I hope I have all that right, but you can double check from the signal names against the Launchpad data sheet). I attached a picture of my setup on a previous mail, but it is hung up waiting for Bill to release it. 73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software*

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One more change to Pacsat basic software
by Burns Fisher (AMSAT) 14 Dec '22

14 Dec '22

The master branch will now work with 2 mrams as I said before. It also can successfully talk to a serial line at 32k8 (and you really have to have that to do anything useful) as well as an AX5043. I have managed to get the 5043 to see a carrier on 2m (the RSSI goes way up) but not to get it to decode anything or transmit anything. I may try that more, but I'm not the 5043 expert by far! After talking with Jim McCullers, I converted all the connections to use inner pins (Booster Pack connectors) rather than the outside pins. Here are all the connections that the software is setup to use: (J2/3 means header J2, pin 3. Pins are counted from 1 on the USB connector end) Power out (to MRAM and AX5043 board) 3.3V Output J2/1 Gnd J5/1 Console serial line: Rx-J2/3 Tx-J2/4 Gnd-J3/2 (Or any other --there are lots) SPI1 (to both MRAMs): Note that the common term for the data lines is MISO and MOSI. TI calls them SOMI and SIMO, the MRAMs just call them SO and SI. MISO: J9/7 MOSI: J9/6 CLK: J67 NCS0: J9/3 (For MRAM 0) NCS1: J9/8 (For MRAM 1) SPI3 (for AX5043--probably for all if we have more than 1) MISO: J5/7 MOSI: J5/6 CLK: J2/7 NCS1 J5/3 (Additional 5043s could use other NCS pins on SPI3. IRQ goes to GIOB[0] J8/8 (I hope I have all that right, but you can double check from the signal names against the Launchpad data sheet). Attached is a picture of the whole thing in my shack. (Ha ha--what a mess!) 73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software*

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Power fail-safe embedded file system for FreeRTOS
by Rich Gopstein 12 Dec '22

12 Dec '22

I found this while poking around. They have both GPL and commercial options. https://www.freertos.org/FreeRTOS-Plus/Fail_Safe_File_System/Reliance_Edge_…

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