If you have a CubeSatSim v1.0, v1.1, or v1.2, you can upgrade it by building a new STEM Payload v1.3 board and replacing your STEM Payload Board.

If instead you want to build a v1.3 CubeSatSim, follow these v1.3 CubeSatSim Instructions

If you already have the v1.3 STEM Payload board built and just need to install it, skip to this step.

Build the Board

Here's what you need:

• STEM Payload Board with SMT parts installed (or, at a minimum, the FM Transceiver module and 1k resistor) Note that the USB-C and the LPF do not matter if they are present.
• The attenuator resistors from Step 1
• A 20x2 GPIO female header (a stacking header can be used, although the non-stacking version is recommended)
• All the parts from Step 2 except the 4.7 k resistors and the diode D7

Start with the PCB with the minimum SMT parts installed:

There are two jumpers on the bottom that you need to bridge with a blob of solder. First, do JP5. Here's how it looks before:

And after adding a solder blob to bridge (short) it:

You should also bridge JP16 to connect the FM Transceiver to your existing antenna. If you want to use a separate antenna for your FM, install the SMA or tape measure antenna on X2. Note that you will need to modify your frame to mount this antenna since the V1 frame only has mounts for one antenna. You could, for example, print a new frame top which has two SMA holes.

Here are the first parts you need to install:

Once they are installed, the board will look like this:

Next, install all the parts in Part 2

The board will look like this:

Install

Follow these steps to Install Software on Raspberry Pi Pico

Plug the Pico and the sensors into the board:

Now, follow the steps to upgrade the software in your Pi Zero to v1.3.

Your Pi Zero will need to have access to the internet to update the software. If you haven't connected your Pi Zero to your WiFi, you will need to do so. An easy way is to run the command sudo raspi-config then select System Options and then Wireless LAN to set your SSID and password. You may also need to set your country for WiFi to work. That is under the Localization Options in this same menu.

Log into your Pi then type these commands:

cd

cd CubeSatSim

git checkout master

git pull

git checkout sr-frs-rx

./update

The new software should then be running after a reboot.

Unplug your old STEM Payload Board and plug in the v1.3 one.

The existing functionality of your CubeSatSim should still be there. You can verify this with the CubeSatSim Test Plan

Run the Upgrade Test Plan to verify the new functionality:

:white_square_button: APRS mode uses the FM transceiver board but only sends a packet every 30 seconds

:white_square_button: You can turn off the APRS packet beacon using an FM carrier transmitted at 435.0 MHz as the APRS packet is transmitted and for a few seconds after. The green LED will blink briefly when the command is received and the blue LED will go off. No further packets will be sent until another carrier is transmitted.

:white_square_button: You can turn back on the APRS packet beacon using an FM carrier transmitted at 435.0 MHz for a few seconds. The green LED will blink briefly when the command is received and the APRS packet should be sent immediately with the blue LED blinking on.

:white_square_button: You can also turn the transmit beacon on and off by logging into your Pi and using the CubeSatSim/config -T command.

:white_square_button: SSTV mode uses the FM transceiver board. Camera images (not stored) display your callsign and the battery voltage (simulated battery voltage not displayed) in black text

:white_square_button: You can turn off the SSTV image beacon using an FM carrier transmitted at 435.0 MHz after an image transmission ends and for a few seconds. The green LED will blink briefly when the command is received and the blue LED will go off. No further images will be sent until another carrier is transmitted.

:white_square_button: You can turn back on the SSTV image beacon using an FM carrier transmitted at 435.0 MHz for a few seconds. The green LED will blink briefly when the command is received and the SSTV image should be sent immediately and the blue LED blink on.

:white_square_button: CW mode uses the FM transceiver board.

:white_square_button: You can turn off the CW beacon using an FM carrier transmitted at 450 MHz after CW transmission pauses and for a few seconds after. The green LED will blink briefly when the command is received and the blue LED will go off. No further images will be sent until another carrier is transmitted.

:white_square_button: You can turn back on the CW beacon using an FM carrier transmitted at 435.0 MHz for a few seconds. The green LED will blink briefly when the command is received and the CW signal will resume and the blue LED blink on.

:white_square_button: In FSK and BPSK modes you can also turn the beacon on and off by transmitting an FM carrier at 450 MHz. You might have to transmit for up to 4 seconds before the green LED blinks and the mode changes.

:white_square_button: In FSK and BPSK modes, in FoxTelem you can see the Ground Commands count displayed in the Computer Software box. Note that it only increments with RF commands not command line commands.