Add SDCard support

internal_filesystem/boot_fri3d-2024.py

@@ -1,5 +1,5 @@
 # Hardware initialization for Fri3d Camp 2024 Badge
-from machine import Pin, SPI
+from machine import Pin, SPI, SDCard
 import st7789 
 import lcd_bus
 import machine
@@ -263,4 +263,8 @@ indev.enable(True)  # NOQA
 import mpos.battery_voltage
 mpos.battery_voltage.init_adc(13, 2 / 1000)
 
+# SD card doesn't need to be plugged in at boot, can be plugged in later
+import mpos.sdcard
+mpos.sdcard.inform_sdcard(machine.SDCard(spi_bus=spi_bus,cs=14))
+
 print("boot.py finished")

internal_filesystem/lib/mpos/sdcard.py

@@ -0,0 +1,72 @@
+import os
+import machine
+
+sdcard = None
+
+# This gets called by (the device-specific) boot*.py
+def inform_sdcard(so):
+    global sdcard
+    sdcard = so
+
+def format_sdcard(sdcard):
+    """Format the SD card with FAT filesystem"""
+    try:
+        print("Formatting SD card...")
+        # Unmount if already mounted
+        try:
+            os.umount('/sdcard')
+        except:
+            pass
+        
+        # Format the SD card (this erases all data!)
+        sdcard.format()
+        print("SD card formatted successfully")
+        return True
+    except Exception as e:
+        print(f"WARNING: Failed to format SD card: {e}")
+        return False
+
+# Tries to mount and returns True if it worked
+def try_mount(sdcard):
+    try:
+        os.mount(sdcard, '/sdcard')
+        print("SD card mounted successfully at /sdcard")
+        return True
+    except Exception as e:
+        print(f"WARNING: failed to mount SD card: {e}")
+        return False
+
+# Returns True if everything successful, otherwise False if it failed to mount
+def mount_sdcard_optional_format():
+    global sdcard # should have been initialized by inform_sdcard()
+
+    if not sdcard:
+        print("WARNING: no machine.SDCard object has been initialized at boot, aborting...")
+        return False
+
+    # Try to detect SD card
+    try:
+        sdcard.info()
+        print("SD card detected")
+    except Exception as e:
+        print(f"WARNING: sdcard.info() got exception: {e}")
+        print("SD card not detected or hardware issue")
+        return False
+
+    if not try_mount(sdcard):
+        if format_sdcard(sdcard):
+            if not try_mount(sdcard):
+                print(f"WARNING: failed to mount SD card even after formatting, aborting...")
+                return False
+        else:
+            print("WARNING: Could not format SD card - check hardware connections or reformat on a PC. Aborting...")
+            return False
+
+    try:
+        print("SD card contents:", os.listdir('/sdcard'))
+    except Exception as e:
+        print(f"WARNING: SD card did not fail to mount but could not list SD card contents: {e}")
+        return False
+
+    print("SD card mounted successfully!")
+    return True