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USB Speed Issue

 
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eoinoc



Joined: 30 Apr 2009
Posts: 16

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USB Speed Issue
PostPosted: Tue Nov 09, 2010 3:17 am     Reply with quote

Hi everyone,

I have a few queries about increasing my USB transfer speed. Here is my current setup

* PIC24FJ32GB002
* Bulk
* Full Speed (Internal Pull up on D+)
* 48MHz USB sourced from 8MHz FRC
* Using EP1 with max packet length set to 255 (Wont be recognised by PC if I make it bigger)
* Using usb_put_packet ( could use usb_puts() maybe ?? )

On PC side I'm using WINUSB and the framework from the Microchip Simple WINUSB demo.

Currently I only achieve approx 64KB/s, every transfer is requested by the computer and a small packet is sent to the PIC ( approx 10 bytes ) on receipt of this packet I then send back 255 bytes to the PC, and this goes on forever.

Any ideas on how I can increase my transfer speed ? 1Mb/s would be nice.
Can I send multiple packets of 255 from PIC to PC? Would certainly reduce overhead involved in sending pkts from PC--> PIC.
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