September 2022 - pacsat - mailman.amsat.org

Power for RTIHU
by Burns Fisher (AMSAT) 23 Sep '22

23 Sep '22

Someone asked last night about how much power the RT-IHU (as seen in the picture) drew. I said something like 300ma. I worked on it today and was able to determine more accurately that the answer is about 200ma (198 really). I did that by turning on my whole board stack and then sending an uplink command to power down the RT-IHU and taking the difference in power use. That includes both AX5043s powered, with one receiving, but the other not transmitting. As to the speed, the oscillator crystal is 16MHz, with an internal PLL bringing it up to 160MHz, which as I read it is the max supported on the TMS570LS0914 processor on that board. It has 1Megabyte of flash program memory and 128KB of RAM (both have ECC). It also has 64KB of data EEPROM with ECC (but we have made a point not to write to flash/prom in orbit just in case it wiped the flash program memory). And finally, the MRAM is Everspin MR25H40, which is 4megabits, that is 512Kbytes. That appears to be the largest available with this model line, although they are introducing a new model line that goes up to 64megabits. I don't know anything about compatibility, although they claim to use SPI interfaces as well. 73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software*

1 0

Fwd: 9600 baud on IC-9700?
by Rich Gopstein 23 Sep '22

23 Sep '22

Some interesting info on falconsat, pacsat, and the IC-9700. ---------- Forwarded message --------- From: Mark L. Hammond <marklhammond(a)gmail.com> Date: Fri, Sep 23, 2022 at 9:31 AM Subject: Re: 9600 baud on IC-9700? To: Rich Gopstein <rich(a)ourowndomain.com>, Andrew Glasbrenner < glasbrenner(a)mindspring.com> Hi Rich, I am delighted to learn about the interest and possibility of a pacsat board! Just coordinate with me and the laws of physics (satellite orbits..) and I can certainly try to turn ON Falconsat-3 for you all. It just won't stay on for more than an orbit or two. Ideally, you all should record some of the data downlink so you can run it at will in the shack and on the bench. In fact, years ago we built an AMSAT digital archive that had recordings of AO-51, which is the same thing...just a thought. I did many modem tests/optimizations using recorded files over the years. If possible, the satellite OS and PBBS really need to be burned into memory onboard the bird, since the uploading of the files needed to run the PBBS take several passes at 9600 baud... Maybe 2 copies, in case one gets bad. Anyhow, Drew KO5MA and I have a lot experience with running AO-51 and Falconsat-3 over the years. Oh, and of course AO-16/17/18/19... The IC-97000 needs to have its FM-D mode act and perform exactly like the FM-D mode in the IC-9100. That gives us audio in and out that supports 9600 baud that be used with TNCs--hardware or software. It's stupid that they dropped 9600 support. In the end, it COULD be as simple as a firmware update for end users. Evidently, they are never going to write the code. Many of us have begged and tried to lobby for it. Here to help as needed! Copying Drew.... 73, Mark L. Hammond [N8MH] AMSAT Director and Command Station On Fri, Sep 23, 2022 at 7:19 AM Rich Gopstein <rich(a)ourowndomain.com> wrote: > There's a new AMSAT project to look at building a "pacsat" board which > will have a 9600 baud downlink. As an exercise, we were going to try > receiving Falconsat transmissions since it uses the same encoding that is > being proposed for the pacsat board. > > There are at least a couple of us who have 9700s and we weren't sure if we > be able to receive at 9600 baud. > > Just out of curiosity, what do you mean by Icom making the 9700 work "the > right way"? > > > > On Fri, Sep 23, 2022, 6:56 AM Mark L. Hammond <marklhammond(a)gmail.com> > wrote: > >> Hi Rich, >> >> Yes, it works on receive. Shame on Icom for making it work "the right >> way"....and not allowing TX at 9700 at all. >> >> It's pretty straightforward. Put the 9700 in FM mode; set the USB audio >> from AF to IF; then point your software decoding program to the 9700 >> soundcard. Pretty much all there is to it...I did this with FoxTLM to copy >> DUV telemetry on the Fox birds, too. Same idea...broadband receive to >> software. Another trick--since it's "only a soundcard" you can run >> multiple decoding software at the same time on the receiver.. >> >> What's your plan for 9600 on the 9700? >> >> Mark L. Hammond [N8MH] >> AMSAT Director and Command Station >> >> >> >> On Thu, Sep 22, 2022 at 10:59 PM Rich Gopstein <rich(a)ourowndomain.com> >> wrote: >> >>> Mark, >>> >>> Burns mentioned that you have successfully received 9600 baud >>> transmissions using an IC-9700? >>> >>> Are the details available somewhere? >>> >>> Thanks. >>> >>> Rich, KD2CQ >>> >>> >>>

1 0

FalconSat-3 Description
by James McCullers 23 Sep '22

23 Sep '22

https://www.amsat.org/getting-started-with-amateur-satellites-falconsat-3/ 58 degrees north/south

1 0

Thoughts about the FoxPac
by Burns Fisher (AMSAT) 22 Sep '22

22 Sep '22

I've been reading some of the documents and since there are a lot of references to Pacsat generically, I'm using "FoxPac" here to mean specifically the design that we are talking about on this mailing list. As I was reading the documentation, one thing stood out to me: There are lots of assumptions, and appropriately so, that the data rate and format is 9600 bps GMSK. One problem with this speed/format is that it is not supported by the most popular satellite radio these days, the ICOM 9700. Heaven knows why ICOM did not choose to support it, but they seem not to be doing anything about it. My thoughts below may be partly selfish since the 9700 is MY radio, but on the other hand, it IS very popular. One workaround: According to Mark Hammond, N8MH, the 9700 CAN be used for 9600 baud reception (by collecting the IQ (essentially IF) output) and decoding it in software. Thus the big problem is the uplink. Bill's initial design calls for 4 uplink receivers and one downlink transmitter. Suppose that the uplink receivers were designed to switch baud rates on command. We could set it by default to have (say) two receiving at 1200 bps and two at 9600 (or some other number). Alternatively, choose certain days when there were 1200 baud receivers operating. Another alternative: This is not a workaround so much as an offshoot project: Design a simple 9600 baud uplink transmitter. There already exists software and hardware for a AX5043 Raspberry Pi shield. We would "only" need to produce more shields (I believe Jonathan has that design), design a power amp for the output of the 5043, and design and write the software on the Pi. TBD whether the Pi software would do the doppler calculations, or whether it would accept commands from a traditional satellite tracking program (the latter certainly seems easier). I just wanted to send these ideas out for people to think about. It's up to Bill whether this is anything to talk about tonight or not. Maybe it is too soon anyway. 73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software*

2 1

Pacsat dev meeting #1
by Bill Reed 21 Sep '22

21 Sep '22

Pacsat Development team: I am planning the first Pacsat development meeting for Thursday, 9/22/2022 at 8PM CDT. I will send out invitations to all members of the pacsat(a)amsat.org mailing list as of 9/21. Think about the task lists and where you would like to get involved. ( and, of course, additional tasks ) Please send comments and ideas to me at nx5r(a)amsat.org Could this extract from the ground station manual be considered our first draft of a CONOPS document? THE AMSAT PACSAT GROUND STATION MANUAL: https://www.g0kla.com/pacsat/pacsat_ground_manual.pdf EXTRACTED FROM THE AMSAT PACSAT GROUND STATION MANUAL: The Pacsat satellite will run software that follows the PacSat protocols. This is a clever set of software routines that provide a delay tolerant network connection to the spacecraft. The protocols are split into two halves. The broadcast protocol and connected mode. The broadcast protocol is used to receive data from the spacecraft. The files and data available on the spacecraft are broadcast as a directory listing. This means that all ground stations can listen and record the data. Specific files are requested by transmitting a broadcast request to the spacecraft. The file is then broadcast in chunks of data and again all ground stations can receive it. Each ground station can then request the parts of the file that they missed. This makes it a very efficient way to communicate data to many stations and makes it possible to download the directory and files across fades and different passes of the spacecraft. To upload files a ground station makes a dedicated connection to the spacecraft by logging in. The spacecraft then confirms space is available and provides the file number to use. The data is then uploaded. Again, this is very delay tolerant and picks up seamlessly across fades or passes. You may think this is all very old and out of date, and perhaps using low speeds at 9600bps is, but the protocols form the basis of modern high speed, delay tolerant communications through spacecraft. It is a very robust solution for transmitting data around the world with no dependence on the telecoms infrastructure. I imagine a similar protocol will server us well when we exchange data with the moon or Mars. If you want to learn more about the Pacsat Protocols then have a look at the reference documents at the bottom of the page at: https://www.g0kla.com/pacsat OTHER INTERESTING LINKS: https://ke0pbr.wordpress.com/2020/11/06/tips-and-tricks-to-work-the-falcons… https://www.youtube.com/watch?v=Hd_8A0Lymzc https://www.youtube.com/watch?v=k6_aD0wQWxM https://www.amsat.org/falconsat-3/ https://www.g0kla.com/pacsat/ THINK ABOUT THESE TASK LISTS Hardware task list: TMS570 development kit AX5043 daughter boards attached to the dev kit Plug on modules for filters, amps and preamps file system memory power Software task list: TMS570 freeRTOS operating system AX5043 configuration and SPI interface multiple uplinks and single downlink file system w/EDAC IHU interface Pacsat protocol VERSION 2 ENHANCEMENTS: 4fsk 100 baud and other formats ???? Bill, NX5R

2 1

I'd like to join the pacsat meeitng
by Burns Fisher (AMSAT) 08 Sep '22

08 Sep '22

73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software*

1 0

I'd like to be on the mailing list
by Rich Gopstein 08 Sep '22

08 Sep '22

Thanks.

1 0

I'd like to monitor the development
by Zach Metzinger 08 Sep '22

08 Sep '22

Thanks! --- Zach N0ZGO

1 0