4 years, 8 months ago.

LPC11u24 SDHC card hangs on fopen

Hi everyone I am hoping you can help me out.

I have a pcb I made with an lpc11u24 on it. I am trying to write to an sd card with this simple code:

#include "mbed.h"
#include "SDFileSystem.h"

SDFileSystem sd(P0_9, P0_8, P0_10, P1_23, "sd"); // MOSI, MISO, SCLK, SSEL
Serial serial(P1_27, P1_26);
DigitalOut led(P0_2);
int main() {
    serial.printf("Hello World!\r\n");
    FILE *fp = fopen("/sd/mbed.txt", "w");
    fprintf(fp, "Hello World!\n");
    while(1) {
        while(serial.readable()) serial.putc(serial.getc());
        led = 1;
        led = 0;
        serial.printf("Goodbye World!\r\n");

When I run the code without an sd card connected, it gives the expected output


Hello World! No disk, or could not put SD card in to SPI idle state Didn't get a response from the disk Set 512-byte block timed out

But when I connect the sd card to the bus, It will just print Hello World and then hang. I think it is stuck on the fopen command.

This code works fine on my mbed LPC1768 dev board (if I change pin numbers of course)

I have read a bunch, some people talk about this operation not fitting in the heap... idk I am hoping you guys and ladies can help!

Thanks a ton! -Eric

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