CubeSatSim

The CubeSat Simulator https://github.com/alanbjohnston/CubeSatSim/wiki 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®.

Requires:

• wiringpi
• libcurl4-openssl-dev
• git

See the Wiki Software Install page for more details: https://github.com/alanbjohnston/CubeSatSim/wiki/Software-Install. To build and run the software on a Raspberry Pi 3B, 3B+, or Pi Zero W: Requires:

• Raspbian Stretch or Buster, full desktop or Lite
• wiringpi
• git
• libasound2-dev
• pi-power-button
• Direwolf
• rpitx

See the Wiki Software Install page for more details: https://github.com/alanbjohnston/CubeSatSim/wiki/Software-Install. To build and run the software on a Raspberry Pi 3B, 3B+, or Pi Zero W (Does NOT work on a Pi 4 since rpitx does not work on it yet):

sudo apt-get install -y wiringpi git libasound2-dev i2c-tools

Run raspi-config and enable the I2C bus by selecting Option 5 Interfacing Options and then Option 5 I2C and selecting Y to enable the ARM I2C bus:

sudo raspi-config

Select Finish at the bottom to exit raspi-config. Then type:

sudo cp /boot/config.txt /bootconfig.txt.0

sudo nano /boot/config.txt

Use the down arrow key to go down in the file until you find this line:

# Additional overlays and parameters are documented /boot/overlays/README

Add the following two lines under it:

dtoverlay=i2c-gpio

dtparam=i2c_vc=on

Press Ctrl-X then type y then hit Enter to save the file and exit the editor. You should back at the pi@... prompt. Reboot by typing:

sudo reboot now

after logging back into the Pi, type:

ls -a /dev/i2c*

you should see three I2C buses:

i2c-0 i2c-1 i2c-3

Continue the install by typing:

cd

Then type:

git clone http://github.com/alanbjohnston/CubeSatSim.git

cd CubeSatSim

Where is the name of this branch of the software, type:

git checkout <branch>

Create a sim.cfg configuration file with your amateur radio callsign by typing:

echo "callsign" >> sim.cfg

Compile the code:

make rebuild

git clone https://www.github.com/wb2osz/direwolf

cd direwolf

make -j

(takes a while)

sudo make install

make install-rpi

Note that this last command may fail if you are using Raspbian Lite since there is no Desktop.

cd ~/CubeSatSim

git clone https://github.com/F5OEO/rpitx.git

cd rpitx

./install.sh

(Takes a while). It will prompt you if you want to modify /boot/config.txt file. Type a y and the script will complete.

cd ~/CubeSatSim

git clone https://github.com/alanbjohnston/pi-power-button.git

cd pi-power-button

./script/install

To make the demo.sh script run automatically on boot:

sudo cp ~/CubeSatSim/systemd/cubesatsim.service /etc/systemd/system/cubesatsim.service

sudo systemctl enable cubesatsim

Now reboot for all the changes to take effect:

sudo reboot now

After rebooting, to hear AFSK telemetry (X.25 data), tune your radio or SDR to 434.9 MHz FM, and you should receive telemetry from the CubeSat Sim:

This code uses the Brandenburg Tech Digital Transceiver, based on DigitalTxRxRP https://brandenburgtech.wordpress.com/ If you don't have the SPI Interface enabled and the board plugged in, you will get an error.

This repository contains:

• afsk - Code that sends telemetry in 1k2 AFSK X.25 format
• arduino - Sample Arduino sketches to show how payload sensors can be interfaced to CubeSat Simulator
• ax5043 - Source for a library of functions to communicate with the AX5043 and configure the AX5043.
• cw - Code that sends telemetry in CW (Morse code) using AO-7 format
• libs - External libraries
• python - Python code for reading I2C sensors for current and temperature
• spreadsheet - Spreadsheets for decoding and analyzing the Simulator telemetry (see https://github.com/alanbjohnston/CubeSatSim/wiki/Decoding-Telemetry for details)
• wav - Wave audio files of CW or AFSK telemetry for listening or transmitting usng a CubeSat Simulator Lite
• demo.sh - a shell script to run the Simulator on boot using systemd (see https://github.com/alanbjohnston/CubeSatSim/wiki/Software-Install#autoboot-configuration for how to configure the Pi)

See the Wiki for more details https://github.com/alanbjohnston/CubeSatSim/wiki