updated to support Teensy 4.1

Author: gigapod

examples/mpy_sdcard_log/mpy_sdcard_log.py

@@ -25,8 +25,6 @@
 
 
 import machine
-from machine import Pin, SPI
-import sdcard
 
 
 import os
@@ -35,36 +33,32 @@
 import random
 import json
 
+SDCARD_MOUNT_POINT = "/sdcard"
+
+# global variable to track if the SD card is mounted
+_mounted_sd_card = False
+
 # Define the boards we support with this deme - This is a dictionary the key being
 # the board uname.machine value, and value a tuple that contains SPI bus number and CS ping number.
 SupportedBoards = {
     "SparkFun IoT RedBoard RP2350 with RP2350": (1, 9),
-    "SparkFun IoT RedBoard ESP32 with ESP32": (2, 5)
+    "SparkFun IoT RedBoard ESP32 with ESP32": (2, 5),
+    "Teensy 4.1 with MIMXRT1062DVJ6A": (-1, -1)
 }
 
 # ------------------------------------------------------------
 
 
-def mount_sd_card():
-    """
-    Mounts an SD card to the filesystem.
-
-    This function checks if the current board is supported, initializes the SPI bus and CS pin,
-    creates the SD card object, and mounts the SD card to the filesystem.
-
-    Returns:
-        bool: True if the SD card was successfully mounted, False otherwise.
-
-    """
+def mount_sd_card(spi_bus, cs_pin):
 
-    # is this a supported board?
-    board_name = os.uname().machine
-    if board_name not in SupportedBoards:
-        print("This board is not supported")
+    global _mounted_sd_card
+    try:
+        import sdcard
+    except ImportError:
+        print("[Error] sdcard module not found. Please install it.")
         return False
 
-    # Get the SPI bus and CS pin for this board
-    spi_bus, cs_pin = SupportedBoards[board_name]
+    from machine import Pin, SPI
 
     # Create the SPI object
     spi = SPI(spi_bus, baudrate=1000000, polarity=0, phase=0)
@@ -81,15 +75,48 @@ def mount_sd_card():
     # Mount the SD card
     try:
         vfs = uos.VfsFat(sd)
-        uos.mount(vfs, "/sd")
+        uos.mount(vfs, SDCARD_MOUNT_POINT)
     except Exception as e:
         print("[Error] Failed to mount the SD Card", e)
         return False
 
-    print("SD Card mounted successfully")
-
+    _mounted_sd_card = True
     return True
 
+
+def setup_sd_card():
+    """
+    Mounts an SD card to the filesystem.
+
+    This function checks if the current board is supported, initializes the SPI bus and CS pin,
+    creates the SD card object, and mounts the SD card to the filesystem.
+
+    Returns:
+        bool: True if the SD card was successfully mounted, False otherwise.
+
+    """
+
+    # is this a supported board?
+    board_name = os.uname().machine
+    if board_name not in SupportedBoards:
+        print("This board is not supported")
+        return False
+
+    # Get the SPI bus and CS pin for this board
+    spi_bus, cs_pin = SupportedBoards[board_name]
+
+    # do we need to mount the sd card? (Teensy auto mounts)
+    status = False
+    if spi_bus != -1:
+        status = mount_sd_card(spi_bus, cs_pin)
+    else:
+        status = True
+
+    if status == True:
+        print("SD Card mounted successfully")
+
+    return status
+
 # ------------------------------------------------------------
 
 
@@ -149,7 +176,7 @@ def setup_log_file(filename):
     """
 
     try:
-        fs = open("/sd/" + filename, "w")
+        fs = open(SDCARD_MOUNT_POINT + os.sep + filename, "w")
     except Exception as e:
         print("[Error] Failed to open log file:", e)
         return None
@@ -219,10 +246,11 @@ def sdcard_log_example(filename="mpy_sdcard_log.txt", count=20, interval=2):
         None
     """
 
+    global _mounted_sd_card
     print("Logging to: {filename}, every {interval} seconds for {count} iterations.\n".format(
         filename=filename, interval=interval, count=count))
     # Mount the SD card
-    if not mount_sd_card():
+    if not setup_sd_card():
         print("Failed to mount SD card")
         return
 
@@ -231,10 +259,11 @@ def sdcard_log_example(filename="mpy_sdcard_log.txt", count=20, interval=2):
     # Log the data
     log_data(filename, count=count, interval=interval, to_console=True)
 
-    # Unmount the SD card
-    uos.umount("/sd")
-
-    print("\nSD Card unmounted successfully")
+    # Unmount the SD card if we need to
+    if _mounted_sd_card:
+        uos.umount(SDCARD_MOUNT_POINT)
+        _mounted_sd_card = False
+        print("\nSD Card unmounted successfully")
 
 # ------------------------------------------------------------
 # Run method for the example