USB device operation help

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by ranaya on Mon Jul 02 20:21:55 MST 2012
Hello Every1......

    I need some advice to make my usb device work. I planned to use it as a self powered device because after the configuration of the device via PC is done, it should operate as a standalone device (data logger).
   According to the getting started doc and forum threads, 5v,D-,D+ and Gnd of USB should be connected to VIN, D-, D+ and GND of the board respectively. And it works.

But to power up the lpc1769 xpresso board as a self powered device, I use a battery supply and connect it to the 2nd pin VIN of the board. And just tied D-, D+ and GND of usb cable to relevant pins. But the usb enumeration does not happen. What might be the cause ? Is it my wiring ? Or the software ? (I modified the descriptor too for selfpowered - VCOM demo project)