Howto let gpredict talk to your Funcube Dongle

If you want to listen to signals from satellites using a Funcube Dongle, it can be nice to automatically adjust the Dongle´s frequency. This page shows you how to setup your system so gpredict sets the frequency, taking the doppler shift into account.

Configuring software to decode the signal your Funcube Dongle receives is not part of this document. Neither is controling a rotor using gpredict.

Requirements (Debian/GNU Linux)

• gpredict (gpredict)

• hamlib utils (libhamlib-utils)

• optional: qthid

Setup

To set permissions on the Funcube Dongle device and create a symlink in /dev/, use these two lines (taken from the qthid README) in a file in your system´s udev directory (/etc/udev/rules.d/ in Debian/GNU Linux). Restart udev after you added the file

# Udev rule for the Funcube Dongle to be used with libusb:
SUBSYSTEM=="usb" ATTRS{idVendor}=="04d8" ATTRS{idProduct}=="fb56" MODE:="0666", SYMLINK+="fcd"

# Udev rule for the Funcube Dongle to be used with HIDAPI/hidraw:
KERNEL=="hidraw*", ATTRS{busnum}=="1", ATTRS{idVendor}=="04d8", ATTRS{idProduct}=="fb56", MODE="0666"

rigctl

We use rigctl and rigctld from hamlib to talk to the Dongle. Test if rigctl can talk to the Dongle by issuing the following command, that attempts to read the frequency the Dongle is currently listening to:

rigctl -m 2513 -r /dev/fcd f

If you get something like rig_open: error = IO error it´s not working. If it prints a number like 97000000 it works! If things work you can use rigctld to permanently talk to your Dongle:

rigctld -m 2513 -r /dev/fcd

gpredict

Start gpredict and go to the global preferences controls. Choose the Radios tab from the Interfaces menu and click on Add New. Choose a name (Funcube) and leave the rest as is, provided you run rgictld on the same machine that runs gpredict.

Once this is done (and rigctld is running), you can tell gpredict to follow a satellite via radio. Click on Module options (usually above the right upper corner of the module window) and choose Radio Control. You should see your freshly configured Funcube in the lower right quarter of the popup. By clicking on Engage you activate the connection between gpredict and rigctld. Next choose a satellite and click Track in the lower left quarter of the popup. Check (using rigctl -m 2513 -r /dev/fcd f) if the frequency on your Funcube Dongle changes. If yes, point your antenna in the direction gpredict tells you (or use a rotor) and listen to the signal.