topic Re: USB bulk transfer speed in Kinetis Microcontrollers https://community.nxp.com/t5/Kinetis-Microcontrollers/USB-bulk-transfer-speed/m-p/813263#M49347 <HTML><HEAD></HEAD><BODY><P>For full speed the packet size is a max of 64 bytes.&nbsp; For high speed it is 512 bytes.<BR /><BR />Set the Polling Interval in the endpoint descriptor to the lowest value that will not generate NAKs on the endpoints.<BR /><BR />Minimize transactions by sending full packets (this may be out of your control in the stock library code).</P><P></P><P><A class="link-titled" href="https://www.beyondlogic.org/usbnutshell/usb4.shtml" title="https://www.beyondlogic.org/usbnutshell/usb4.shtml">USB in a NutShell - Chapter 4 - Endpoint Types</A>&nbsp;</P></BODY></HTML> Thu, 23 Aug 2018 12:24:26 GMT bobpaddock 2018-08-23T12:24:26Z USB bulk transfer speed https://community.nxp.com/t5/Kinetis-Microcontrollers/USB-bulk-transfer-speed/m-p/813262#M49346 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P>I use latest USB stack on MK22 MCU (full speed usb transceiver). I achieve approx 600 kB/s transfer rate when sending data from MCU to PC (Windows 10) via bulk endpoint.</P><P></P><P>On PC I read data using libusb (libusb_bulk_transfer(devHandle, endpoint, data, requiredSize, &amp;actualSize, timeout)).</P><P></P><P>Can you please help in optimizing the transfer rate (i.e. achieving higher transfer rate)? Is there any configuration in USB stack which can achieve higher transfer rate?&nbsp;What is optimal data chunk size written to&nbsp;endpoint in MCU (USB_DeviceSendRequest())?</P></BODY></HTML> Wed, 22 Aug 2018 11:26:04 GMT https://community.nxp.com/t5/Kinetis-Microcontrollers/USB-bulk-transfer-speed/m-p/813262#M49346 martindusek 2018-08-22T11:26:04Z Re: USB bulk transfer speed https://community.nxp.com/t5/Kinetis-Microcontrollers/USB-bulk-transfer-speed/m-p/813263#M49347 <HTML><HEAD></HEAD><BODY><P>For full speed the packet size is a max of 64 bytes.&nbsp; For high speed it is 512 bytes.<BR /><BR />Set the Polling Interval in the endpoint descriptor to the lowest value that will not generate NAKs on the endpoints.<BR /><BR />Minimize transactions by sending full packets (this may be out of your control in the stock library code).</P><P></P><P><A class="link-titled" href="https://www.beyondlogic.org/usbnutshell/usb4.shtml" title="https://www.beyondlogic.org/usbnutshell/usb4.shtml">USB in a NutShell - Chapter 4 - Endpoint Types</A>&nbsp;</P></BODY></HTML> Thu, 23 Aug 2018 12:24:26 GMT https://community.nxp.com/t5/Kinetis-Microcontrollers/USB-bulk-transfer-speed/m-p/813263#M49347 bobpaddock 2018-08-23T12:24:26Z