Communication with USB Devices

Another (hopefully) quick question:

Is there any way to use a UART on the raptor to communicate with a USB device?

For example, if I wanted to use the USB interface of a pololu mini servo controller that has a mini-usb connector.

Physically, the USBHost module has a USB port, but it looks to be only for HID/Storage devices, and not usable as a serial port.

The USB Serial Module has a micro USB connector, so it looks like it is USB-client not USB-host (can’t connect it to another micro-usb connector)

Is there any convenient solution for this? I realize I could just use the ttl pins on that servo controller, but I’d like to see if there was a way to use the usb.


USBHost has a Serial connection method. But that requires that what you plug in actually offers a serial port - do you know that the Pololu device is a serial device ? If so, USB Host is the way to use it.

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Thanks for that!

It would have been nice if there had been a link to that page from the USB Host Module pages. There is no example/tutorial/developers guide listed in the resources there. I was limited to looking through the intellisense list looking for anything to do with serial.

Thanks for the link!

Using the GHI tutorial you linked to at

…I am running into immediate problems with this:

Controller is a USBHost module, but there is no "UsbSerialConnected" according to intellisense...

There are events for KeyboardConnected MouseConnected,MassStorageMounted etc

but no UsbSerialConnected.

What am I missing?

So… has anyone actually seen/used .UsbSerialConnected?

Is it something that was removed from 4.3?

check the definitive reference

Thanks Brett

I figured out my problem.

I misread the code in the tutorial… I thought “Controller” was the name of the instantiated usbhost module object itself. I was trying like this:

In order to use the Serial functionality you need to use the [b]static[/b] GHI.Usb.Host.Controller object  like this:

GHI.Usb.Host.Controller.UsbSerialConnected += Controller_UsbSerialConnected;

Thanks for your help!

BTW I got a package from Australia today. Thanks!

great news on both fronts - did you figure out what the mystery item was ?

The CANxtra board? That’s what it is right?

I had to to some searching to find out what it was :slight_smile:

Did anyone ever write a DeviceNet stack for it?

yep a CANxtra.