The PROVES Prime Mainboard

Trying out a single board implementation for the PROVES Kit again!

Design Objectives

The core goal of the PROVES Kit is to provide a low cost and accessible means of getting working hardware and software in outer space. We interpret that goal as the following:

Having a satellite architecture that:
- Costs approximately $1000 
- Can be built in one day and 
- Will die when it deorbits. 

Depending on how the Pleiades - Orpheus mission goes, V1.5 of the kit may have already acomplished that! There is a big problem with V1.5 though, technical debt from patchwork development over the last year has made it rather complicated and not easy to replicate outside of the Bronco Space Lab. As a result, here we are trying to semi clean sheet a V2 design of the kit for much quicker and easier builds!

Planned Changes From V1.5

Major Updates: - Returning to a PyCubed Style Mainboard / Battery Board Scheme - Removing the secondary microcontroller - Reworking the electrical power subsystem - Adding options for multi-radio setup - Rework of the connectors and harnessing system - Designing for scalability with larger and more complex payloads

Dev Logs

This section is for a running log of development activities! The goal is with regular "dev diary" sort of updates to be able to track the logic behind alot of the PROVES Prime Design Decisions.

February 9, 2025 | Expanding on the Minimum Viable Satellite

It has been a couple slower than expected weeks for development! The main thing we have to share at this point is that we've slightly refined what we are thinking of when we talk about the MVS. The attatched block diagram helps explain what our current thinking is.

The general concept here is that the MSP430RF used at the core of the MVS system will have the ability to monitor and manipulate the overall power distribution to the rest of the satellite system using its GPIO. In a way, this chip is now going to be the supervisor that ensures all of the satellite's subsystems are behaving. Having this be a seperate chip rather than rolling it into the RP2350 frees up I/O and simplifies the software that needs to run on the RP2350 so it can focus on the mission needs rather than satellite oversight.

January 26, 2025 | The First Devlog!

Okay so this is where we're starting with trying to actively track the development of this board! Currently the two design contributors are Michael Pham, Rachel Rakushkin, and the Hacker LMBFAO. At this stage we have some preliminary component select and schematic migration from the existing PROVES boards complete.

Overall Architecture Plan

Right now our thought is to run a hybrid architecture where there is a ultra-low power microcontroller (the MSP430FR line most likely) that runs a "Minimum Viable Satellite" (MVS) alongside an RP2350 microcontroller that will run most of the satellite systems and interface with payload data collection. The attatched block diagram reflects the thinking here.

The big idea here is that we have a somewhat modular MVS section of the board, that is able to support the most essential satellite systems in the safest and simplest way possible, running alongside the core systems connected to the RP2350, which will do all of the mission data collection and satellite management. The thought is that we can rely on the MVS at all times to provide a satellite beacon with the most important satellite metadata while allowing the core systems to run a little more fast and loose with the RP2350.

The MSP430 (despite being a pretty ancient microcontroller) has plenty of proven heritage in spaceflight and industrial applications. Particularly the FR varients use FRAM which lends an increased resistance to radiation upsets and permits the microcontroller to run a very low power. As a center of the MVS, this microcontroler will have access to the 435Mhz band UHF radio, the system and solar power monitors, and GPIO that connects to the enable pins of the 3v3 and 5v regulators. That last element giving the MVS the ability to "turn the sateliite off and on again" if it is ever needed. This system will then interface with the RP2350 core through a UART connection.

LT8610 Switching Voltage Regulator Designs

One of the other big changes from all previous PROVES Kits is that we leaving behind the TPS5422X series of switching voltage regulators and instead using the LT8610 series. We get a minor improvement in efficiency and compactness by doing this, but one of the biggest reasons we are making this switch is because there seems to be pretty promising raditation data from ESA on these chips!

Link to ESA Radiation Database

Rachel led the design of both the 3.3V and 5V switching regulator schematics. The preliminary schematics are attatched here.

!Rachel's Schematics

Quick References

This is a section for storing quick reference images and notes regarding the design of the PROVES Prime Mainboard.

RP2350 Pin Definitions

!!! "Source" https://datasheets.raspberrypi.com/rp2350/rp2350-datasheet.pdf