USB Probe <---> Embedded Controller <---> Web Server

[Joe0x7F]

Hello Everyone,

I have an embedded controller with a USB port and an Ethernet port on it.

My intent is to read data from a "web server" over TCP/IP sockets with the embedded controller and then send that data out the USB port of the embedded controller to a USB 2.0 connected probe to another device.

I am writing the code for the embedded controller.

I have all of Jan's books, at least the latest ones, and I would like someone to point me in the direction of the USB material that I should focus on. I believe I can handle the TCP/IP portion of this project OK, but I need direction on the USB half.


Thanks!

Joe
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[Jan Axelson]

Every USB communication is between a host and a device, so if the probe is a device, your embedded system must have a USB host port.

How the host communicates with the device depends on the device's USB class or vendor-defined protocols.

Jan

[Joe0x7F]

Hi Jan,

Thanks. What differentiates a device from a host? I mean, what's to say that the probe is not a host?
I know that the probe has some sort of USB circuit in it that I have not studied yet. It's a USB to optical probe, so it converts whatever is coming down the USB cable from the PC into light pulses to talk to the other device. It has one LED for transmit and a photo-transistor for receive.

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[Joe0x7F]

The USB connection on the embedded controller is a "USB 2.0 Full-Speed OTG port".

[Jan Axelson]

If you can attach the probe to a PC, it's a device and you will need to program the embedded controller in host mode.

Jan

[Joe0x7F]

Thanks Jan, now I know what to focus on! Thanks!!!