LPC4357 USB serial host

[quyenngo]

I want to use USB port on LPC4357 as USB serial host and communicate with FTDI chip via FT232R USB UART.

I use nxpUSBlib, CDC class for communicate. At the enumerate process, the usb lib return that it’s is not valid CDC device when it read the device descriptor.

Is CDC Class host is the right way for communicate with FTDI USB UART chip and if it’s not, which is the correct way for using NXPUSBlib

to communicate with FTDI USB UART chip?

[isaacavila]

Hello Quyen,

FTDI devices use vendor specific comands which requires an specific protocol/driver. LPC USB Host CDC example is design to communicate with standard CDC devices, that is why you cannot communicate with it.

I am attaching an USB capture where an FTDI device was connected. As you can see, it is shown as vendor-specific protocol:

When connecting a FTDI device, its descriptors contain just one interface that uses vendor-specific class so Host cannot find an endpoint to configure this device (this should be done through device’s driver, but Host could not look for a vendor-specific driver)

I hope this can help you!

Regards,

Isaac