mrubyc-gem-sdcard

ESP32 SPI SD Card library.

Description

This commit adds ESP32's SPI SD Host Controller support for mruby/c.
You can use stdio.h and driver/sdspi_host.h APIs from mruby/c with this commit.

Warning

This program doesn't check arguments.
So if you use wrongly(e.g. you passed wrong typed values or not enough count of arguments), it segfaults.

Additional Information

(C) Matsue College of Technology.
このプログラムは松江高専の授業中に作成されました．

Added APIs

SDSPI class

This class have methods about SPI initialization and FileSystem mounting.

Limitation

This class only have one SD card and first partition.
You want to extend to be able to use multiple SD card, you should create instancing-able class about SD card.
That class must hold sdmmc_host_t and sdmmc_card_t.
mruby/c seems to have special method to create instance with additional space to remember C structures, but it is not documented and cannot guarantee the class have additional space DEFINITELY.

If you want to see second and later partitions, you may create vfs program yourself because I can't find any API to look other partitions.

SDSPI#spi_bus_initialize(mosi : Integer, miso : Integer, sclk : Integer) -> bool

Pass SPI pin numbers, MOSI(Master out slave in), MISO(Master in slave out), SCLK(SPI Clock).
This method initializes SPI Bus.
If success, return true, otherwise false.

SDSPI#esp_vfs_fat_sdcard_mount(cs : Integer, mount_point : String) -> bool

Pass CS(Chip Select, also called Slave Select).
2nd argument is a path where to mount on. e.g. "/sdcard".
This method initializes vfs module and mount file system.
If success, return true, otherwise false.

SDSPI#esp_vfs_fat_sdcard_unmount() -> bool

This method unmounts file system.
If success, return true, otherwise false.

SDSPI#spi_bus_free() : bool

This method frees the SPI Bus.
This returns nothing.

ESP32_STDIO class

This class provides stdio.h functions.

Limitation

You can open up to 8 files.

ESP32_STDIO#fopen(filename : String , openmode : String) -> Integer

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fopen.html
This returns file id instead of FILE pointer. If fails, return -1.

ESP32_STDIO#fclose(fid : Integer) -> bool

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fclose.html
This need file id instead of FILE pointer.
If success, return true, otherwise false.

ESP32_STDIO#fputs(fid : Integer, content : String) -> bool

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fputs.html
This need file id instead of FILE pointer and String instead of char pointer.
If success, return true, otherwise false.

ESP32_STDIO#fputc(fid : Integer, content : String) -> bool

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fputc.html
This need file id instead of FILE pointer and String instead of char.
If success, return true, otherwise false.

ESP32_STDIO#fwrite(fid : Integer, content : String, size : Integer, nitems : Integer) -> bool

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fwrite.html
This need file id instead of FILE pointer and String instead of char.
If success, return true, otherwise false.

ESP32_STDIO#fputc(fid : Integer, content : String, size : Integer, nitems : Integer) -> bool

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fputc.html
This need file id instead of FILE pointer and String instead of char.
If success, return true, otherwise false.

ESP32_STDIO#fgets(fid : Integer, length : Integer) -> String

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgets.html
This need file id instead of FILE pointer.
If success, return content typed String, otherwise nil.

ESP32_STDIO#fread(fid : Integer, size : Integer, nitems : Integer) -> String

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fread.html
This need file id instead of FILE pointer.
If success, return content typed String, otherwise nil.

ESP32_STDIO#fgetc(fid : Integer, length : Integer) -> String

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgetc.html
This need file id instead of FILE pointer.
If success, return content typed String, otherwise nil.

ESP32_STDIO#fflush(fid : Integer) -> bool

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fflush.html
This need file id instead of FILE pointer.
If success, return true, otherwise false.

ESP32_STDIO#fgetpos(fid : Integer) -> Integer

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgetpos.html
This need file id instead of FILE pointer.
If success, return true, otherwise false.

ESP32_STDIO#fsetpos(fid : Integer) -> Integer

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fsetpos.html
This need file id instead of FILE pointer.
If success, return true, otherwise false.

ESP32_STDIO#fseek(fid : Integer, offset : Integer, whence : Integer) -> Integer

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/fseek.html
This need file id instead of FILE pointer.
SEEK_SET is 0, SEEK_CUR is 1, SEEK_END is 2.
If success, return true, otherwise false.

ESP32_STDIO#remove(filename : String) -> bool

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/remove.html
If success, return true, otherwise false.

ESP32_STDIO#rename(src : String, dst : String) -> bool

See https://pubs.opengroup.org/onlinepubs/9699919799/functions/rename.html
If success, return true, otherwise false.

ESP32_DIRENT class

This class provides directory information and file time stamp API.

ESP32_DIRENT#childrenFiles(directory : Name) -> String[]

Enumerated files contained selected directory(argument directory).
If succeeded, return array of String, name of files contained, otherwise nil.

ESP32_DIRENT#childrenDirs(directory : Name) -> String[]

Enumerated directories contained selected directory(argument directory).
If succeeded, return array of String, name of directories contained, otherwise nil.

ESP32_DIRENT#children(directory : Name) -> String[]

Enumerated both files and directories contained selected directory(argument directory).
If succeeded, return array of String, name of entries contained, otherwise nil.

ESP32_DIRENT#fileTime(entryName : Name) -> ESP32_FILETIME

Get created date of given file.
If succeeded, return ESP32_FILETIME, otherwise nil.
ESP32_FILETIME have these members, all return values are Integer.
getYear(), getMonth(), getDay(), getDayOfWeek(), getHour(), getMinute(), getSecond().