AMSAT CubeSatSim STEM Payload Pico firmware v1.3.2.3 (beta)
===========================================================

WHAT THIS IS
------------
Beta firmware (UF2) for the Raspberry Pi Pico on the CubeSatSim STEM Payload
board, version 1.3.2.3, built from stempayload/Payload_BME280_MPU6050_XS. It
is attached to beta release v1.3.2.3 (2024-03-29) and again, byte-identical,
to beta release v1.3.2.4 (2024-08-01), whose notes say "there are no updates
with this release" for the Pico. The notes add that the previous v1.3.2.2
payload firmware "will work since the updates are minor." Superseded by
payload firmware 2.0.1 (release v2.0).

The CubeSatSim software is released under the GNU General Public License
version 3 (the repository's LICENSE file, formerly gpl.txt). The source of
this firmware is in the repository at the release tag named in PROVENANCE. The
board designs are separately licensed CC-BY-NC-SA by AMSAT.

APPLIES TO
----------
The Raspberry Pi Pico or Pico W on the Beta v1.3.2 PCB boards
(https://github.com/alanbjohnston/CubeSatSim/tree/beta/hardware/beta-v1.3.2),
used with the v1.3.2.x beta Raspberry Pi software. The release notes say the
beta Pi software also runs on v1.2 boards.

Not for the v0.x Pico-only port.

BEFORE STARTING
---------------
  - A computer with a USB port and a micro-USB data cable.
  - Access to the Pico's BOOTSEL button.
  - The v1.3.2.x beta software on the Pi Zero (git branch beta).

CONTENTS OF THIS ZIP
--------------------
The zip published on fubsypoly.com wraps the vendor file byte-for-byte,
unmodified.

Payload_BME280_MPU6050_XS.v.1.3.2.3.rpipicow.uf2
    702,976 bytes
    SHA-256 d297be2cd8e28941c4b5be6a6935c80a11167ae6358f13ee68a08123bdc4764e
    UF2 firmware image for the RP2040 (Raspberry Pi Pico).
README.txt
    This file.
SHA256SUMS
    SHA-256 checksums of the files above.

INSTALLATION
------------
 1. Plug the Pico into a computer through the Pico's own micro-USB port
    while holding down the white BOOTSEL button on the Pico.
 2. The Pico mounts as a USB drive named RPI-RP2.
 3. Drag (copy) the .uf2 file from this zip onto the RPI-RP2 drive. The
    Pico reboots into the new firmware when the copy completes and the drive
    disappears.
 4. Optionally open the Pico's USB serial port in the Arduino IDE Serial
    Monitor or a terminal program such as PuTTY to watch the log and make
    configuration changes.

Steps 1-4 follow the project's release notes. The release notes do not give
a baud rate for the serial log; this could not be confirmed.

VERIFYING
---------
Watch the serial output as above; where the version string is printed could
not be confirmed. The v1.3.2.x notes give 434.9 MHz as the transmit frequency
and 435.0 MHz as the command receive frequency.

IF SOMETHING GOES WRONG
-----------------------
  - The RP2040's BOOTSEL USB bootloader is in the chip's mask ROM, so a
    failed or interrupted copy is recovered by holding BOOTSEL, reconnecting
    and copying the .uf2 again.
  - If RPI-RP2 does not appear, the cable is probably charge-only; use a
    data cable.
  - Kits ship with the Pico already programmed; reflashing is needed only
    to update or to recover.

DOWNGRADING
-----------
Possible: any release's .uf2 can be copied onto the Pico in BOOTSEL mode in
the same way, older or newer. Match the firmware to the board and to the
Raspberry Pi software version it is meant to run with (see APPLIES TO).

PROVENANCE
----------
- File: Payload_BME280_MPU6050_XS.v.1.3.2.3.rpipicow.uf2
- Downloaded from:
  https://github.com/alanbjohnston/CubeSatSim/releases/download/v1.3.2.3/Payload_BME280_MPU6050_XS.v.1.3.2.3.rpipicow.uf2
- Identical asset also attached to release v1.3.2.4.
- Retrieved: 2026-09-18
- Official page: https://github.com/alanbjohnston/CubeSatSim/releases/tag/v1.3.2.3
- Status: verified (the project's own GitHub pre-release, unmodified)

MORE INFORMATION
----------------
  - CubeSatSim deep dive: https://radios.fubsypoly.com/cubesatsim/
    (build and software loading: vol-3; operation and modes: vol-5)
  - Project releases: https://github.com/alanbjohnston/CubeSatSim/releases
  - Project wiki: https://github.com/alanbjohnston/CubeSatSim/wiki
  - Project site and downloads: https://cubesatsim.org/download/
