This directory has experimental CubeSatSim code for the Raspberry Pi Pico.  It is functionally equivalent to the CubeSatSim code that runs on the Raspberry Pi Zero, but on runs on the cheaper and easier to find Raspberry Pi Pico microcontroller.

Here's how to use it.

If all you want is a binary file to program your Pico, then go to the Releases t

You will need the Arduino IDE (Integrated Development Environment) application which you can download here: https://www.arduino.cc/en/software for different OSes. 
I am using version 1.18.19

You will need the cubesatsim code on your computer.  If you have git installed, you can clone the repository by typing:

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

git checkout pico

git pull

If you don't, you can download a ZIP file with the code https://github.com/alanbjohnston/CubeSatSim/archive/refs/heads/pico.zip

Unzip the pico.zip file

Run the Arduino IDE

In the menu, select File Open then move to the CubeSatSim-pico/cubesatsim directory and you will see cubesatsim.ino.  Select this file then click Open.

The "sketch" will open and you should see a view like this.

Next, you need to install the Raspberry Pi Pico Arduino core, called 'Arduino-Pico'. From their documentation: "Arduino-Pico is a community port of the RP2040 (Raspberry Pi Pico processor) to the Arduino ecosystem, intended to make it easier and more fun to use and program the Raspberry Pi Pico / RP2040 based boards."

Here is the documentation for Arduino-Pico: https://arduino-pico.readthedocs.io/en/latest/

Follow the installation instructions listed here: https://arduino-pico.readthedocs.io/en/latest/install.html

If you use Windows, pay attention to this: "Note for Windows Users: Please do not use the Windows Store version of the actual Arduino application because it has issues detecting attached Pico boards. Use the “Windows ZIP” or plain “Windows” executable (EXE) download direct from https://arduino.cc. and allow it to install any device drivers it suggests. Otherwise the Pico board may not be detected."

Once you have installed it, you can now select the Pico board so you can compile the code.

Under the menu Tools / Board select "Raspbery Pi RP2040 Boards(2.1.1)" then select "Raspberry Pi Pico" which is the first one in the list.  You can use a Pico W board, but select it as "Raspberry Pi Pico" anyway.

Next you need to install some libraries.

You need to download the Arduino-APRS library and the SSTV-Arduino-Scottie1 library and add to your Arduino libraries.

Go to the release page for each: https://github.com/alanbjohnston/Arduino-APRS/releases and https://github.com/alanbjohnston/SSTV-Arduino-Scottie1/releases and https://github.com/alanbjohnston/Duino-hacks/releases 

Select the latest release then download the zip files Arduino-APRS-Library.zip and SSTV-Arduino-Scottie-Library.zip and Duino-hacks.zip 

In the Arduino IDE, under the menu select Sketch / Include Library then select "Add .ZIP library" find the ZIP files you downloaded and add both of them.

Next, install some libraries by going under the menu Tools/ Manage Libraries.  At the search box at the top, type MPU6050_tockn and hit enter.  Mouse over the library desciption and click on the Install button.

Do the same for the following libraries:

Adafruit INA219

Adafruit BME280

RPI_PICO_TimerInterrupt

JPEGDecoder

FastCRC

Find the ZIP file you downloaded and select it.

Do a test compile by clicking the check in the Arduino IDE. If you get an error, click on Copy Error Message and paste it into a text editor and see which library is missing.

To compile and download to your Pico board, you need to have the Port selected.  If the Pico is mounted as a flash drive (look for a drive called "RPI-RP2" on your desktop), then you don't need to select anything for the Port.  If it is not mounted as a flash drive, look under Port for "Raspberry Pi Pico" and select it.  If it doesn't show, try unplugging and plugging in the Pico board again. If that still doesn't work, unplug the Pico, hold down the BOOTSEL button while plugging it back in and it should mount as a flash drive.  Click on the Arrow to compile and upload.  NOTE: the upload will always fail for the Pico if the Serial Monitor is open, so always close it before uploading.  If you have to plug and unplug the Pico while you develop, don't unplug and plug the micro USB connector on the Pico.  Instead, do it on the other end the cable.  The micro USB connector is weak and may fail with too many cycles.