This guide describes on how to setup DigiLink Nano on a Raspberry Pi running the latest version of Raspbian (Buster). DigiLink Nano does not require a driver on Linux since Linux supports USB's Audio Device Class natively.
Plug DigiLink Nano into any USB device on your Raspberry Pi. After a few seconds, the device should be automatically detected and registered with the system. Please run the following command in a shell window to check that the device has been properly identified:
You should see an entry named CODEC [USB audio CODEC]. Should you not see this entry, please unplug DigiLink Nano, wait a few seconds and plug it in again. After a few seconds, run the following command and check if you see the output below:
If you don't see this in the output of dmesg, DigiLink Nano is not detected correctly. Double check your USB cable and try again, maybe use a different cable just to be sure. If you still don't see DigiLink Nano recognised by the system, please get in touch with me.
If the device has been registered properly, open Audio Device Settings. You will need these to adjust the output and input levels as needed, so it's best to have them visible at all times.
In the new window, please select the following sound card: USB audio CODEC (Alsa mixer). Then press Select Controls and select all checkboxes. Click Close.
CAUTION: Do not make this sound card default to keep system and other applications' sounds away from your radio.
With the new controls, please separate left and right Speaker channels by clicking the chain symbol so it shows an open chain. Set the right channel to full volume since it is used for DigiLink Nano's VOX circuit. If you would rather like to use your radio's VOX control, set the right channel's volume to zero.
Use the left Speaker channel to change the output volume to your radio, or set it to a convenient level for your radio and use your radio's control's to fine-adjust the level as needed (this depends on your radio, as for myself I use full volume for the KX2/KX3 and fine-adjust with the MIC button but for my FT-897 I set radio to a 50 and fine-adjust in Raspbian's Audio settings as the radio's sensitivity setting is hidden in its menu and not conveniently availably on a know as on the KX2/KX3).
IMPORTANT: The Microphone in the Playback settings is not really a microphone but the loopback from input to output on DigiLink Nano's audio codec (it feeds back the the signal received by the radio back into the radio's microphone input). This has to be muted, otherwise you will see signal distortions making your transmissions unreadable by receivers and it might even spuriously key your transmitter.
Please select the Capture tab. Here, you can adjust the input sensitivity of DigiLink Nano. Again, it might be easier to set this level to a convenient level and fine-tune the right level on your radio or vice-versa.
A general word on these levels: it is recommended to work with the highest reasonable levels on the line, i.e. the cable between your DigiLink Nano and your radio to maximize signal to noise ratio on the line (there will always be noise induced into the connection, therefore having a high signal on the connection increases signal to noise ratio. Please still make sure not to overdrive your transmitter or DigiLink's input and always maintain some headroom on the input to account for RF signal variations).
Your are now all set to use DigiLink Nano to make contacts with digital Ham Radio modes. There are two more optional sections below explaining how to install and configure the most popular Ham Radio software packages on your Raspberry Pi, so please read them if you haven't done so already.
Open Add / Remove Software in your preferences.
In the new window, enter fldigi into the search field in the top left side and press enter. Select all search results and press OK to install these packages. You will be prompted for your password.
Enter your password and press OK. The selected software packages should now be installed.
You should now have a new menu entry Hamradio and see the installed software packages in there. Select Fldigi.
Please follow these instructions to setup fldigi now.