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. 


  1. Ouch :( That is pretty disappointing.

  2. It may not be CDC-ACM, but it does work fine in Linux. I am running Ubuntu 10.10. It is using the cp210x driver which yields a ttyUSB0 device. I fire up minicom, set the baud rate to 9600 and I have communications. The big question is WHAT to communicate.

    I installed the MCP-4A program via wine and was able to start to see some of the commands sent there (via wireshark sniffing the USB port).

    I am currently able to get what looks like a 65kB dump from the device, but I have yet been able to fully decipher the contents.

  3. Cool stuff, Vernon. I'm having no trouble with it in Linux, either. In fact, it works wonderfully on my MacBook Pro and a Ubuntu image over Virtualbox. (Whereas I think the MBP needs a driver to talk to this device itself!)

    My disappointment was regarding how hard it will be to get a PIC to communicate with the cp2102, since one of my projects has been using a PIC or Atmel chip to control a TH-D7a through a simple TTL->RS232 interface. Although Microchip provides libraries for CDC-ACM, communicating with this device in such a context will entail porting the Linux code to the PIC32.

    To be clear, I don't think Kenwood did the wrong thing. USB is obviously the way to go, and the cp2102 is a reliable device. It just makes my little world of fun a bit more challenging :-)