We're designing a board based on the Kinetis K60. The K60 only has 5 UARTs, and we need to interface to 7 UART devices, so there is a lack of serial ports. We're looking into the possibility of using a USB-to-serial converter chipset to add a couple more UART interfaces to the board. The USB side of the converter would be wired into the K60, and the K60 would act as the host.
The MQX v3.6.3 release notes indicate that there's support for the USB Host Communication Device Class (CDC), so I think we're covered, so long as we can locate a suitable USB-to-serial converter chipset that supports the USB CDC.
I've taken a look at a couple converters (FTDI FT232R, and Silicon Labs CP2105), but I don't see any indication that either of these support USB CDC.
My questions are: Has anyone attempted anything like this before? If so, what type of USB-to-serial converter chipset was used, and what was the result?
Ideally, I'd like to obtain a list USB CDC chipsets that are officially supported by (or at least tested with) MQX. Perhaps the Freescale folks can help out with this one?