Welcome to the AMSAT® CubeSatSim Project Wiki, the CubeSat Simulator

The CubeSatSim is a low cost satellite emulator that runs on solar panels and batteries, transmits UHF radio telemetry, has a 3D printed frame, and can be extended by additional sensors and modules. This project is sponsored by the not-for-profit Radio Amateur Satellite Corporation, AMSAT®.

This page is for the new Beta v1.3 hardware.

If you have the v1.0, v1.1, or v1.2 hardware, use these instructions

Here you will find documentation about this project and detailed install instructions.

The CubeSatSim has the following features:

• Working solar panels and rechargeable batteries
• Multi-channel voltage, current, and temperature telemetry transmitted in the Amateur Radio UHF band
• Telemetry decoding using FoxTelem software or APRS software
• STEM Payload board with Raspberry Pi Pico microcontroller & sensors
• Tape measure monopole, dipole, or SMA antenna
• Integrated Low Pass Filter
• 3D printed frame and solar panels

If you don't have the time or money to build a CubeSatSim that transmits real telemetry, you can build a CubeSat Simulator Lite.

Here are the changes between the v1.2 and the Beta v1.3 hardware and software.

These improvements are available to new Beta v1.3 CubeSatSim builders or v1.0, v1.1, or v1.2 CubeSatSims which can be upgraded with a new Beta v1.3 STEM Payload board and software upgrade:

• New FM transceiver module for better frequency stability and simple command and control receiver to turn beacon on and off using radio
• More modern and cheaper Raspberry Pi Pico micro controller on STEM Payload board
• Easily connect additional sensors for the Pico using the Qwiic connector system https://www.sparkfun.com/qwiic
• SSTV camera images now display callsign and battery status overlay
• Can be modified to fly as a balloon payload with 500mW FM output for SSTV, APRS, or CW transmissions with software support on Pico for a serial GPS module

These improvements are available to new Beta v1.3 CubeSatSim builders:

• Lower parts cost and easier to source. All parts can now be sourced from electronics distributors and Amazon including easy to find solar panels. New BOM uses Octopart electronic part inventory site with one click distributor ordering
• Redesigned for blue INA219 voltage and current sensors instead of more expensive purple ones
• Battery board now has integrated voltage and current sensor and PTC fuse with better performance
• Simpler electrical power system with no boost converter or charge control circuit
• Kits can be built with through hole parts except for a few SMT parts. Fully assembled boards will be available in the future using SMT parts
• Easily connect additional sensors for the Raspberry Pi Zero the Qwiic connector system

Here are the four boards that make up the complete board stack. Left to right: Raspberry Pi Zero WH with Pi Camera, Battery Board, STEM Payload Board with FM module, and Solar Board.

Here is the built board stack:

There is a 3D printed frame, including solar panels:

Here is a block diagram of the design:

Parts List to build the CubeSatSim is available here https://docs.google.com/spreadsheets/d/1EuUqyKnXduMlDo9ghCWJu1VY-y2_TWXYRR3S3zGaw9s/edit?usp=sharing
Here is a photo of a kit of parts:

Here are the steps to build a CubeSatSim:

1. Build the STEM Payload Board Part 1

2. Install the Software

3. Build a Ground Station

4. Continue Building the STEM Payload board Part 2

5. Build the Battery board

6. Assemble the Solar Panels and Frame

7. Build the Solar board

8. Put the Board Stack together and mount in the Frame

9. Final Testing

The BOM has a sheet "By Steps" which lists the parts needed for each step in order. https://docs.google.com/spreadsheets/d/1EuUqyKnXduMlDo9ghCWJu1VY-y2_TWXYRR3S3zGaw9s/edit?usp=sharing If you have a Google account, you can make a copy of this spreadsheet ("File" then "Make a Copy") and check off each part as you install it.

Here is a set of videos showing the various steps: