Does this setup work? Communication from PIC32 --> USB2517 --> PIC18

[pratiken]

Hi everyone,
I'd like to know if this works technically. I'm not an embedded systems engineer.

I have plans to make a main control device powered by a PIC32MX795F512L that also has a 7 port USB hub on the same PCB powered by the USB2517.

The PIC32 will connect to the computer via USB CDC and Ethernet.

Connected to the USB ports will be 7 slave PIC18F2550 devices. Commands are sent to the PIC32, which forwards them to the corresponding slave PIC18. The PIC18 performs the commands on slave IC's via SPI.

Technically, does this all work together like I am thinking it will?

Thanks!!

 

[horace1]

this should work - the PIC32 can run a USB host protocol and the PIC18s the corresponding device protocol

what USB protocol are you considering?

the critical thing is how much data will you be transferring per second, e.g. HID is typically limited to 64Kbytes/second

have you considered using CANbus or wired Ethernet 10baseT to connect the devices?

 

[FvM]

The PIC32 will connect to the computer via USB CDC and Ethernet.

The PIC32 can either act as an USB host or a device, either connect to the hub upstream port or to a PC USB port. In so far the intended topology isn't feasible.

Embedded hosts may include hub support in it's list of targetted devices according to the OTG spec, but I don't expect that there's much hub support provided by the microchip usb library.

 

[horace1]

I missed that there was also a USB connection to the PC as well as to the PIC18s devices - in effect one would requie a micro with two USB ports?

any particular reason to connect to the PC by both USB and Etherenet?

 

[horace1]

some microcontrollers have two USB ports, e.g. the TI TMS320C6747
https://www.ti.com/product/tms320c6747/description

why not connct the PIC18s directly to the PC via a hub? what is the PIC32 doing?