File System

File access is standard .NET (System.IO.File, Directory, Stream) on the on-board storage, SD cards and USB drives. The Endpoint-specific GHIElectronics.Endpoint.Devices.Storage package handles the hot-plug events and mount folder for removable media.

• On-board storage: always mounted and available to System.IO the moment your program starts. The partition at /data/ is where deployed applications live.
• SD card: mounts at /media/sd/ when a card is present.
• USB mass storage: each drive gets the next free /media/usbN/ folder, the same way Windows gives each one the next free drive letter.

SD card

Open the SD-card controller, subscribe to ConnectionChanged, and mount the drive when it connects. Everything from System.IO then works against the returned path.

.NET

using GHIElectronics.Endpoint.Core;
using GHIElectronics.Endpoint.Devices.Storage;

var sd = StorageController.FromName(EPDomino24.StorageController.SdCard);

sd.ConnectionChanged += (sender, e) => {
    if (e.DeviceStatus == DeviceConnectionStatus.Connected) {
        var drive = FileSystem.Mount(e.Hdc);           // "/media/sd/"
        File.WriteAllText(Path.Combine(drive.Name, "log.txt"), "Hello SD");
        FileSystem.Flush(e.Hdc);                        // write everything before unmount / pull
    }
    else {
        Console.WriteLine("SD card removed");
    }
};

sd.Enable();   // the card already in the slot is reported too

Python

import os
from GHIElectronics.Endpoint.Core import EPDomino24, DeviceConnectionStatus
from GHIElectronics.Endpoint.Devices.Storage import FileSystem, StorageController

sd = StorageController.FromName(EPDomino24.StorageController.SdCard)

def on_changed(sender, e):
    if e.DeviceStatus == DeviceConnectionStatus.Connected:
        drive = FileSystem.Mount(e.Hdc)                # "/media/sd/"
        with open(os.path.join(drive.Name, "log.txt"), "w") as f:
            f.write("Hello SD")
        FileSystem.Flush(e.Hdc)                        # write everything before unmount / pull
    else:
        print("SD card removed")

sd.ConnectionChanged += on_changed
sd.Enable()   # the card already in the slot is reported too

C/C++

#include <cstdio>
#include <fstream>
#include <endpoint/EPDomino24.h>
#include <endpoint/Storage.h>

using namespace GHIElectronics::Endpoint::Core;
using namespace GHIElectronics::Endpoint::Devices::Storage;

auto sd = StorageController::FromName(EPDomino24::StorageController::SdCard);

sd.ConnectionChanged += [](StorageController&, const DeviceConnectionEventArgs& e) {
    if (e.DeviceStatus() == DeviceConnectionStatus::Connected) {
        auto drive = FileSystem::Mount(e.Hdc());       // "/media/sd/"
        std::ofstream(drive.Name() + "log.txt") << "Hello SD";
        FileSystem::Flush(e.Hdc());                    // write everything before unmount / pull
    }
    else {
        std::puts("SD card removed");
    }
};

sd.Enable();   // the card already in the slot is reported too

USB mass storage

Same shape as above, with a different controller name. Multiple USB drives can be plugged in at once; each one fires ConnectionChanged with its own Hdc, and each mounts to its own /media/usbN/.

.NET

using GHIElectronics.Endpoint.Core;
using GHIElectronics.Endpoint.Devices.Storage;

var usb = StorageController.FromName(EPDomino24.StorageController.UsbHostMassStorage);

usb.ConnectionChanged += (sender, e) => {
    if (e.DeviceStatus == DeviceConnectionStatus.Connected) {
        var drive = FileSystem.Mount(e.Hdc);           // "/media/usb0/", usb1, ...
        Console.WriteLine($"Mounted {drive.Name}, label '{e.VolumeLabel}'");

        foreach (var file in Directory.EnumerateFiles(drive.Name))
            Console.WriteLine(file);
    }
    else {
        Console.WriteLine("USB drive removed");
    }
};

usb.Enable();

Python

import os
from GHIElectronics.Endpoint.Core import EPDomino24, DeviceConnectionStatus
from GHIElectronics.Endpoint.Devices.Storage import FileSystem, StorageController

usb = StorageController.FromName(EPDomino24.StorageController.UsbHostMassStorage)

def on_changed(sender, e):
    if e.DeviceStatus == DeviceConnectionStatus.Connected:
        drive = FileSystem.Mount(e.Hdc)                # "/media/usb0/", usb1, ...
        print(f"Mounted {drive.Name}, label {e.VolumeLabel!r}")
        for name in os.listdir(drive.Name):
            path = os.path.join(drive.Name, name)
            if os.path.isfile(path):
                print(path)
    else:
        print("USB drive removed")

usb.ConnectionChanged += on_changed
usb.Enable()

C/C++

#include <cstdio>
#include <filesystem>
#include <endpoint/EPDomino24.h>
#include <endpoint/Storage.h>

using namespace GHIElectronics::Endpoint::Core;
using namespace GHIElectronics::Endpoint::Devices::Storage;

auto usb = StorageController::FromName(EPDomino24::StorageController::UsbHostMassStorage);

usb.ConnectionChanged += [](StorageController&, const DeviceConnectionEventArgs& e) {
    if (e.DeviceStatus() == DeviceConnectionStatus::Connected) {
        auto drive = FileSystem::Mount(e.Hdc());       // "/media/usb0/", usb1, ...
        std::printf("Mounted %s, label '%s'\n", drive.Name().c_str(), e.VolumeLabel().c_str());

        for (const auto& entry : std::filesystem::directory_iterator(drive.RootDirectory())) {
            if (entry.is_regular_file())
                std::puts(entry.path().string().c_str());
        }
    }
    else {
        std::puts("USB drive removed");
    }
};

usb.Enable();

tip

Always call FileSystem.Flush(e.Hdc) after writing and before the drive is pulled out. On Endpoint, as on a PC, System.IO.DriveInfo.VolumeLabel returns the drive's mount folder rather than its label. Use e.VolumeLabel from the event to read the actual label.