My board is very simple at the moment, I only have:
*)Pwr, GND
*)USB
*)UART to FTDI USB (PIO0_0 and PIO0_1)
*)Jumpers for ISP Boot pins.
I only use internal clocks on chip.
My board will boot up and show the CRP DISABLD device on my PC (when I boot from USB/MSC).
I tried the hello world example in the LPC51U68 SDK, and I changed SDK Debug consle to UART console. I downloaded the app, and set the MCU to boot from flash. I did not get any printouts on the UART (I use TeraTerm on PC setup according to NXP guide with FTDI TTL-232R cable).
And then when I switch back to boot from USB it will no longer show the CRP DISABLD device. The hello world example is really small so I am not sure what I am doing wrong. As long as the hello world uses internal clocks then there should be no problems with my board.
int main(void)
{
char ch;
/* Init board hardware. */
/* attach 12 MHz clock to FLEXCOMM0 (debug console) */
CLOCK_AttachClk(BOARD_DEBUG_UART_CLK_ATTACH);
BOARD_InitPins();
BOARD_BootClockFROHF48M();
BOARD_InitDebugConsole();
PRINTF("hello world.\r\n");
while (1)
{
ch = GETCHAR();
PUTCHAR(ch);
}
}
So in conclusion I have two problems:
1) USB Device no longer shows up after change of firmware.
2) No printouts on the UART to FTDI USB.