roman strizhev / _NUCLEO-L476RG_

example NUCLEO-L476RG STM32

/* Licensed under the Apache License, Version 2.0 (the "License");

  1. include "mbed.h"
  2. include <stdio.h>
  3. include <errno.h>
  4. include <functional>
  5. include "BlockDevice.h"

Maximum number of elements in buffer

  1. define BUFFER_MAX_LEN 10
  2. define FORCE_REFORMAT true This will take the system's default block device BlockDevice *bd = BlockDevice::get_default_instance(); OK

Можно создать файловую систему в ОЗУ(куча, heap) Instead of the default block device, you can define your own block device. For example: HeapBlockDevice with size of 2048 bytes, read size 1, write size 1 and erase size 512. #include "HeapBlockDevice.h" BlockDevice *bd = new HeapBlockDevice(2048, 1, 1, 512);OK! создает, но 2048 будет мало для эксперимента BlockDevice *bd = new HeapBlockDevice(1024*72, 1, 1, 512);32kByte хватает для создания небольшой ФС в ОЗУ! (LittleFS, для FATFS - мало, 72kB - OK )

This example uses LittleFileSystem as the default file system #include "LittleFileSystem.h" LittleFileSystem fs("fs"); OK!!

Uncomment the following two lines and comment the previous two to use FAT file system.

  1. include "FATFileSystem.h" FATFileSystem fs("fs");

Set up the button to trigger an erase InterruptIn irq(BUTTON1);OK повесим прерывание на пользовательскую кнопку void erase() { printf("Initializing the block device... "); fflush(stdout); int err = bd->init(); printf("%s\n", (err ? "Fail :(" : "OK")); if (err) { error("error: %s (%d)\n", strerror(-err), err); }

printf("Erasing the block device... "); fflush(stdout); err = bd->erase(0, bd->size()); printf("%s\n", (err ? "Fail :(" : "OK")); if (err) { error("error: %s (%d)\n", strerror(-err), err); }

printf("Deinitializing the block device... "); fflush(stdout); err = bd->deinit(); printf("%s\n", (err ? "Fail :(" : "OK")); if (err) { error("error: %s (%d)\n", strerror(-err), err); } }

static auto erase_event = mbed_event_queue()->make_user_allocated_event(erase);OK

DigitalOut led(LED1);

  1. define WAIT_MS 1000 void wait(int ms){ wait_us(ms*WAIT_MS); }

int main() { printf("START_default_1\n"); ======================================================================================== printf("- Mbed OS filesystem example -\n");

Setup the erase event on button press, use the event queue to avoid running in interrupt context irq.fall(std::ref(erase_event));

Try to mount the filesystem printf("Mounting the filesystem... "); fflush(stdout); int err = fs.mount(bd); printf("%s\n", (err ? "Fail :(" : "OK")); if (err || FORCE_REFORMAT) { Reformat if we can't mount the filesystem printf("No filesystem found, formatting... "); fflush(stdout); err = fs.reformat(bd); printf("%s\n", (err ? "Fail :(" : "OK")); if (err) { error("error: %s (%d)\n", strerror(-err), err); } }

Open the numbers file printf("Opening \"/fs/numbers.txt\"... "); fflush(stdout); FILE *f = fopen("/fs/numbers.txt", "r+"); printf("%s\n", (!f ? "Fail :(" : "OK")); if (!f) { Create the numbers file if it doesn't exist printf("No file found, creating a new file... "); fflush(stdout); f = fopen("/fs/numbers.txt", "w+"); printf("%s\n", (!f ? "Fail :(" : "OK")); if (!f) { error("error: %s (%d)\n", strerror(errno), -errno); }

for (int i = 0; i < 10; i++) { printf("\rWriting numbers (%d/%d)... ", i, 10); fflush(stdout); err = fprintf(f, " %d\n", i); if (err < 0) { printf("Fail :(\n"); error("error: %s (%d)\n", strerror(errno), -errno); } } printf("\rWriting numbers (%d/%d)... OK\n", 10, 10);

printf("Seeking file... "); fflush(stdout); err = fseek(f, 0, SEEK_SET); printf("%s\n", (err < 0 ? "Fail :(" : "OK")); if (err < 0) { error("error: %s (%d)\n", strerror(errno), -errno); } }

Go through and increment the numbers for (int i = 0; i < 10; i++) { printf("\rIncrementing numbers (%d/%d)... ", i, 10); fflush(stdout);

Get current stream position long pos = ftell(f);

Parse out the number and increment char buf[BUFFER_MAX_LEN]; if (!fgets(buf, BUFFER_MAX_LEN, f)) { error("error: %s (%d)\n", strerror(errno), -errno); } char *endptr; int32_t number = strtol(buf, &endptr, 10); if ( (errno == ERANGE) || The number is too small/large (endptr == buf) || No character was read (*endptr && *endptr != '\n') The whole input was not converted ) { continue; } number += 1;

Seek to beginning of number fseek(f, pos, SEEK_SET);

Store number fprintf(f, " %d\n", number);

Flush between write and read on same file fflush(f); } printf("\rIncrementing numbers (%d/%d)... OK\n", 10, 10);

Close the file which also flushes any cached writes printf("Closing \"/fs/numbers.txt\"... "); fflush(stdout); err = fclose(f); printf("%s\n", (err < 0 ? "Fail :(" : "OK")); if (err < 0) { error("error: %s (%d)\n", strerror(errno), -errno); }

Display the root directory printf("Opening the root directory... "); fflush(stdout); DIR *d = opendir("/fs/"); printf("%s\n", (!d ? "Fail :(" : "OK")); if (!d) { error("error: %s (%d)\n", strerror(errno), -errno); }

printf("root directory:\n"); while (true) { struct dirent *e = readdir(d); if (!e) { break; }

printf(" %s\n", e->d_name); }

printf("Closing the root directory... "); fflush(stdout); err = closedir(d); printf("%s\n", (err < 0 ? "Fail :(" : "OK")); if (err < 0) { error("error: %s (%d)\n", strerror(errno), -errno); }

Display the numbers file printf("Opening \"/fs/numbers.txt\"... "); fflush(stdout); f = fopen("/fs/numbers.txt", "r"); printf("%s\n", (!f ? "Fail :(" : "OK")); if (!f) { error("error: %s (%d)\n", strerror(errno), -errno); }

printf("numbers:\n"); while (!feof(f)) { int c = fgetc(f); printf("%c", c); }

printf("\rClosing \"/fs/numbers.txt\"... "); fflush(stdout); err = fclose(f); printf("%s\n", (err < 0 ? "Fail :(" : "OK")); if (err < 0) { error("error: %s (%d)\n", strerror(errno), -errno); }

Tidy up printf("Unmounting... "); fflush(stdout); err = fs.unmount(); printf("%s\n", (err < 0 ? "Fail :(" : "OK")); if (err < 0) { error("error: %s (%d)\n", strerror(-err), err); }

printf("Mbed OS filesystem example done!\n");

======================================================================================== while(1) { моргаем встроенным светодиодом led = !led; wait(100); } }

History