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®.

There are several hardware versions and software branches to go with them - see below for information.

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 (doesn't work on Pi 4 since rpitx doesn't work on it yet): 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 /boot/config.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

dtoverlay=pi3-miniuart-bt

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

Edit the cmdline.txt file by typing:

sudo cp /boot/cmdline.txt /boot/cmdline.txt.0

sudo nano /boot/cmdline.txt

Remove the following text in cmdline.txt to prevent a console from running on the serial port:

console=serial0,115200

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 two I2C buses:

i2c-1 i2c-3

Continue the install by typing:

cd

Then type:

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

cd CubeSatSim

git checkout master

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

echo "callsign" >> sim.cfg

Compile the code:

make rebuild

cd

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 (you may get an error such as this "ln: failed to create symbolic link '/home/pi/Desktop/direwolf.desktop': No such file or directory make: *** [Makefile.linux:727: install-rpi] Error 1"

cd

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

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, tune your radio or SDR to 434.9 MHz FM, and you should receive telemetry from the CubeSatSim!

You can stop the service:

sudo systemctl stop cubesatsim

After rebooting, it will start unless you disable it:

sudo systemctl disable cubesatsim

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

Older Versions

There are several versions of the hardware and software to go with them:

• The original design used a Digital Transceiver Board for the Raspberry Pi (DigitalTxRxRPi) and APRS AFSK 1200 bps telemetry only. Use the aprs-digitaltxrx branch for this and the vB2 wiki page https://github.com/alanbjohnston/CubeSatSim/wiki/vB2-Home
• An updated design that used the Transmitter/Filter Board (TFB) instead of the the Transceiver Board. For the same APRS AFSK telemetry, use the aprs-rpitx branch and the vB3 wiki page https://github.com/alanbjohnston/CubeSatSim/wiki/vB3-Home. Note that this hardware can still use the master code branch.