One comment and volunteer: I have already ported FreeRTOS to the TMS570 for Golf, and Rich and I have a single AX5043 running under FreeRTOS (taking advantage of interrupts, FreeRTOS task waits, etc. I make no claim that it is done the best way possible, but it's a start. I volunteer to provide a "bare-bones" version of FreeRTOS on TMS570 with the ability to talk to an AX5043. Clearly there will be more to do since there are more 5043s probably using different protocols from Golf and (maybe?) no hot-standby TMS570 like Golf has. In any case, I look forward to contributing.
73,
Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software*
On Wed, Sep 21, 2022 at 12:35 PM Bill Reed bill@brconnect.com wrote:
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@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@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-falconsa... 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
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