# LPC1343 evaluation board USB bootloader not working?

My LPC1343 no longer shows up as a USB mass storage device.

I am using the following evaluation board for NXP's LPC1343:

http://www.embeddedartists.com/sites/default/files/support/qsb/lpc1343/LPC1343_QuickStart_Board_Users_Guide.pdf

I plug in with mini USB, file system opens. I deleted the default firmware.bin and loaded my own based on the code of this library: https://github.com/microbuilder/LPC1343CodeBase (without modifying)

I then pressed some combination of the reset and bootloader buttons. And now my device no longer appears on my Windows PC when I plug in USB (e.g. I can't see firmware.bin in device's folder).

Is it possible I accidentally activated a code read protection mode? I really hope not... http://www.nxp.com/documents/application_note/AN10968.pdf

Thanks for any help.

## 2 Answers

Most likely, your code has some weird oscillator config settings which cause it to crash on start-up, or does something that otherwise prevents the USB MSC boot-loader from working. You should be able to bypass your code and get into the USB boot-loader again by setting PIO0_1 to 0, PIO0_3 to 1, and resetting.

Most probably there is chance that you may declare the port 0 (PIO0_1) as output port.So the microcontroller cant able to get the input values as you pass in that port.Mostly the chip you use is using USB terminal as programming end.certain condition is needed to work as USB ISP as described in application note.

Better to program using SWD with proper input output declaration will hopefully eliminate this problem.

The problem will also happens in Arduino as arduino is programmed through UART,sometimes people may declare this port as output mean,next time when programming through UART will have some problem.