Friday, December 10, 2010

More on the TH-D72 USB Port

The TH-D72 USB port is configured as a CDC device, using the CP2102 USB UART bridge. On Windows, presumably you should use the drivers provided by Kenwood. I accessed the port on my Ubunutu 10.04 desktop just by using /dev/tty.USB0, which popped open when I connected the device. CP2102 support evidently is built into recent kernels. Looking around, it seems that MacOS support is more dicey, so I'll probably experiment with it using a linux box or a virtual linux machine on my MacBook.

For the person like me, who is hoping to connect this to an embedded device, there's some particularly bad news: this chip doesn't communicate using the plain CDC-ACM; I'm told it has a proprietary communication system to the host. The best bet is to port the software from the linux kernel, alas. 

Commanding the TH-D72

The new TH-D72 is a dandy radio, with APRS and a built-in GPS engine. But I was a bit dismayed to see that the CAT commands are somewhat different from those for the TH-D7G, since I'd put quite a bit of time into programming for those. Guessing that Kenwood wouldn't rewrite this software for each rig, I took a look at this list of commands for the most recent similar radio, the TM-D710, and sure enough, it seems they work. Phew.

In addition, if we want a micro-controller to talk to this thing, then I suppose it will need to have USB host mode on it, since the rig acts as a USB device, of course. The CUI32 apparently provides the hardware for this connection, so we'll see how that works.