# oresat/oresat-c3-hardware architecture

> Architecture diagram of the GitHub repository oresat/oresat-c3-hardware, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-09-30). It is an AI-made overview: check details against the source.

- Interactive diagram: https://gitdiagram.com/oresat/oresat-c3-hardware
- Repository: https://github.com/oresat/oresat-c3-hardware

## Overview

This repository is the KiCad hardware design for OreSat’s C3 command, communication, and control card—not its Python flight software. The documented user-facing workflow is receiving ground commands and providing telemetry; the README does not identify which radio implements each path. The graph preserves the board’s major documented hardware capabilities, using schematic paths as component evidence. No source excerpts were provided, so internal wiring and control relationships are omitted.

Main entry points: [`oresat-c3-card/oresat-c3.kicad_sch`](https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3.kicad_sch) (C3 control card)

## Diagram (Mermaid)

```mermaid
flowchart TD

subgraph group_compute["Onboard computing"]
  node_processor["OSD335x processor"]
  node_watchdog["Watchdog timer"]
end

subgraph group_radio["Radio communications"]
  node_lband["L-band receiver"]
  node_uhf["UHF transceiver"]
end

subgraph group_storage["Storage and timing"]
  node_emmc[("eMMC storage")]
  node_fram[("FRAM storage")]
  node_rtc["Backup RTC"]
end

subgraph group_interfaces["Power and interfaces"]
  node_opd["OPD controls"]
  node_antenna["Antenna deployment"]
  node_power["Power circuitry"]
end

node_ground(("Ground station"))
node_c3["C3 control card"]

node_ground -->|"sends commands"| node_c3
node_c3 -->|"provides telemetry"| node_ground

click node_c3 "https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3.kicad_sch"
click node_processor "https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-osd3358-sip-e-f.kicad_sch"
click node_watchdog "https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-watchdog.kicad_sch"
click node_lband "https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-l-band.kicad_sch"
click node_uhf "https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-uhf-band.kicad_sch"
click node_emmc "https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-osd3358-sd-emmc.kicad_sch"
click node_fram "https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-opd-and-i2c.kicad_sch"
click node_opd "https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-opd-and-i2c.kicad_sch"
click node_antenna "https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-opd-and-i2c.kicad_sch"
click node_power "https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-power.kicad_sch"

classDef toneNeutral fill:#f8fafc,stroke:#334155,stroke-width:1.5px,color:#0f172a
classDef toneBlue fill:#dbeafe,stroke:#2563eb,stroke-width:1.5px,color:#172554
classDef toneAmber fill:#fef3c7,stroke:#d97706,stroke-width:1.5px,color:#78350f
classDef toneMint fill:#dcfce7,stroke:#16a34a,stroke-width:1.5px,color:#14532d
classDef toneRose fill:#ffe4e6,stroke:#e11d48,stroke-width:1.5px,color:#881337
classDef toneIndigo fill:#e0e7ff,stroke:#4f46e5,stroke-width:1.5px,color:#312e81
classDef toneTeal fill:#ccfbf1,stroke:#0f766e,stroke-width:1.5px,color:#134e4a
class node_processor,node_watchdog toneBlue
class node_lband,node_uhf toneAmber
class node_emmc,node_fram,node_rtc toneMint
class node_opd,node_antenna,node_power toneRose
class node_ground toneIndigo
class node_c3 toneTeal
```

## Components

### Onboard computing

- [OSD335x processor](https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-osd3358-sip-e-f.kicad_sch): `oresat-c3-card/oresat-c3-sch-osd3358-sip-e-f.kicad_sch`
- [Watchdog timer](https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-watchdog.kicad_sch): `oresat-c3-card/oresat-c3-sch-watchdog.kicad_sch`

### Radio communications

- [L-band receiver](https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-l-band.kicad_sch): `oresat-c3-card/oresat-c3-sch-l-band.kicad_sch`
- [UHF transceiver](https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-uhf-band.kicad_sch): `oresat-c3-card/oresat-c3-sch-uhf-band.kicad_sch`

### Storage and timing

- [eMMC storage](https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-osd3358-sd-emmc.kicad_sch): `oresat-c3-card/oresat-c3-sch-osd3358-sd-emmc.kicad_sch`
- [FRAM storage](https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-opd-and-i2c.kicad_sch): `oresat-c3-card/oresat-c3-sch-opd-and-i2c.kicad_sch`
- **Backup RTC**

### Power and interfaces

- [OPD controls](https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-opd-and-i2c.kicad_sch): `oresat-c3-card/oresat-c3-sch-opd-and-i2c.kicad_sch`
- [Antenna deployment](https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-opd-and-i2c.kicad_sch): `oresat-c3-card/oresat-c3-sch-opd-and-i2c.kicad_sch`
- [Power circuitry](https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3-sch-power.kicad_sch): `oresat-c3-card/oresat-c3-sch-power.kicad_sch`

### Other components

- **Ground station**
- [C3 control card](https://github.com/oresat/oresat-c3-hardware/blob/master/oresat-c3-card/oresat-c3.kicad_sch): `oresat-c3-card/oresat-c3.kicad_sch`

## Connections

- Ground station → C3 control card: sends commands (evidence: `README.md`)
- C3 control card → Ground station: provides telemetry (evidence: `README.md`)