The following steps are taken if you want to run the simpleusb radio driver rather than usbradio. Why would you want to do this? The simpleusb driver is less CPU intensive and requires less resources. So if you have an older computer that is bogging down, running this driver can be a good thing. If you run the top command and see that asterisk is taking up 20% or more CPU cycles and your machine is under heavy load, give this a try.

However, if you use simpleusb you must configure the radio to provide COR and perform all CTCSS functions (transmit and receive). That’s where the savings comes in. the usbradio driver is able to do DSP and figure out when there is signal in all the noise as well as encode and decode CTCSS. By relieving the driver of those responsibilities and making the radio take care of that, we lighten the load on the computer.

  1. Copy /usr/src/astsrc/configs/simpleusb/simpleusb.conf to /etc/asterisk/
  2. Edit simpleusb.conf to define the parameters for each and every node you have connected to this computer. For this example I am working on node 27006 so I have a section in this file called [usb27006] that defines the hardware connection to the radio.
  3. Remove /etc/asterisk/usbradio* You might want to just move those files so you have them somewhere, but they can’t be in /etc/asterisk. Having a usbradio.conf and simpleusb.conf in that directory at the same time is bad, confuses things, will frustrate you and should not be done. Just make the usbradio.conf file go away. Thanks.
  4. Delete /etc/init.d/usbradio
  5. Create a new file using the command: touch /etc/init.d/simpleusb
  6. Using vi, or your other favorite editor, change the entry in /etc/asterisk/rpt.conf for your nodes so the rxchannel parameter uses SimpleUSB/node where node refers to the stanza we talked about above in step 2. In my case for node 27006 we see that as: rxchannel=SimpleUSB/usb27006
  7. Restart asterisk. A reboot at this point wouldn’t be a bad thing if you’re local to the machine (doing this remotely might not be wise anyway).

Note that the tuning for your radio is now handled differently than what you might be used to.  Rather than going into the Asterisk CLI, you’ll work from the Linux Bash command prompt and execute the simpleusb-tune-menu utility.