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Beep-Sat is a complete software example for a simple beaconing satellite that performs a handful of tasks and runs forever.

Highlights

(top ⬆)

⭐ Software architecture that is easy to understand & build-upon

A simple asynchronous state machine schedules and runs routine spacecraft tasks

• Each task definition is contained within a single plain-text file
• Task files are easily added, removed, or modified

⭐ Well documented code with real-time debug messages

Entire code base includes thorough in-line commentary & insight

• During operation, descriptive messages are printed to the USB serial terminal
• Helpful coding patterns are discussed and software decisions are justified

Overview

As introduced in Hands-On Quick Start, whenever a PyCubed board is powered, it loads and runs main.py from the board's root directory.

• For this Beep-Sat example, all main.py does is automatically load each task file found within the /Tasks/ directory into a state machine and then runs the state machine indefinitely.
• Each task file defines its priority and frequency attributes to inform the state machine how often to run the task.
• This demo relies on a lightweight asyncio library called Tasko to achieve pseudo-asynchronous behavior. But remember there are countless other ways of achieving this functionality!

Installation

1. Download the latest Beep-Sat code from its GitHub Repo (either download the zip or if you're familiar with git, fork & clone the repo)

2. (Optional) With your PyCubed board plugged into your computer, backup your PYCUBED drive by copying its contents to a directory on your computer.

3. Copy the files from /software_example_beepsat/basic/ to your PYCUBED drive, overwriting any files when prompted

4. Open a serial terminal and observe the output as the beep-sat conducts its mission.

   Refer to Accessing the Serial Console for help opening the REPL

5. After observing the output in the terminal for a few moments, start working through understanding each task by stepping through the code breakdown discussion (below) while opening and playing with its respective file in /Tasks/task_filename.py.

Required Hardware

• [ ] PyCubed Mainboard

Code Breakdown & Task Explanation

1. Blink LED task

Priority: 255

Frequency: twice per second (2 Hz)

Very simple task to blink the onboard RGB LED. With a priority of 255, Blink has a very low priority and will be preempted by most all other tasks.

2. Report IMU data task

Priority: 5

Frequency: once every 10 seconds (0.1 Hz)

This task demonstrates an important spacecraft function: how to perform routine sensor data collection over common serial buses such as I2C, SPI, or UART.