Enhanced Command and Control - alanbjohnston/CubeSatSim GitHub Wiki

The Beta v1.3.2 CubeSatSim can support DTMF and APRS packet command and control by running Direwolf on the Pi Zero.

This is built into the latest beta release, but it needs some extra hardware:

• USB sound card that plugs into the Pi Zero
• OTG cable that plugs into the micro USB on the Pi Zero and the sound card plugs into it
• 3.5mm connector (just like the RBF) which has two wires that connect to the GPIO header on the Solar PCB.

The v1.3.2.3 STEM Payload PCB also has a 2.5mm jack for the audio signal. To use this, this additional part is needed:

• 2.5mm to 3.5mm jumper

When these are connected, Command and Control can be turned on by using the Pi Zero command:

  CubeSatSim/config -T

This will default to the Carrier (squelch) command and control. To select the DTMF or APRS command and control, use this command:

 CubeSatSim/config -d

Note that if no USB sound card is detected, this mode will not run.

Once running, you can check the Command and Control logs with:

 CubeSatSim/log -c

DTMF commands are sent by transmitting (pressing and holding the PTT) on the RX frequency, then pressing a number (1 - 5 for the five modes) and then '#' - you will hear two tones transmitted. For APRS packet commands, anywhere in the packet should be the message Mode=x where x is either a, f, b, s, m for the five modes, or o to turn telemetry on or off.

Here are the commands:

 To select APRS mode, transmit DTMF `1#` or `Mode=a`
 To select FSK mode, transmit DTMF `2#` or `Mode=f`
 To select BPSK mode, transmit DTMF `3#` or `Mode=b`
 To select SSTV mode, transmit DTMF `4#` or `Mode=s`
 To select CW mode, transmit DTMF `5#` or `Mode=m`
 To turn transmission of telemetry on or off, transmit DTMF `10#` or `Mode=o` where o is the Letter O.

One way to transmit packet command and control is to use Quan Sheng with updated firmware.