# rsta2/circle

A C++ bare metal environment for Raspberry Pi with USB (32 and 64 bit)

Repository: https://github.com/rsta2/circle
Canonical: https://ross.abutalabs.com/products/rsta2-circle
Homepage: https://circle-rpi.readthedocs.io
Language: C
License: GPL-3.0
License Family: copyleft
Topics: raspberry-pi, c-plus-plus, bare-metal, usb, tcp-ip
Last push: 2026-08-26T08:12:11+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 4331, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2295, forks 302 (observed 2026-08-28T04:06:35.155019+00:00)

## What it is
Circle is a C++ bare metal programming environment for the Raspberry Pi, providing ready-tested classes and add-on libraries to control hardware features without an operating system. It supports 32-bit and 64-bit applications and includes a TCP/IP network stack, USB support, and sample programs.

## Use cases
- write bare metal applications for Raspberry Pi
- build an OS kernel for Raspberry Pi from scratch
- control Raspberry Pi hardware directly without Linux
- run a TCP/IP network stack on bare metal Raspberry Pi
- develop 64-bit bare metal firmware for Raspberry Pi
- access USB devices from bare metal code

## When to choose
- you need to run code on a Raspberry Pi without an operating system
- you want fine-grained control over Raspberry Pi hardware like GPIO, USB, or Ethernet
- you are building an embedded or hobby OS project on Raspberry Pi
- you need a bare metal TCP/IP stack with socket API

## When to avoid
- you want to build a normal Linux application for Raspberry Pi
- you need a full-featured RTOS with scheduling guarantees out of the box
- you target hardware other than Raspberry Pi
- you prefer a C-only environment without C++ classes

## Facets
- artifact type: framework
- maturity: active
- function: embedded, networking, sdk, developer-tools
- domain: embedded-systems, hardware, operating-systems, developer-tools
- platform: embedded, cross-platform, cpp
- tags: bare-metal, raspberry-pi, tcp-ip-stack, c-plus-plus, firmware, no-os, usb

## Member repositories
- rsta2/circle (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:35.155019+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:40:23.702735+00:00, confidence not recorded.
  - readme: https://github.com/rsta2/circle (fetched 2026-08-28T04:06:35.155019+00:00, sha e6d07c1b15e5)
- Data as of 2026-08-30T08:39:29.467469+00:00.