Add function to check flash storage size and free space

lib/robot.py

+import os
 from micropython import const
 from machine import Pin, I2C, Timer, WDT
 from time import sleep, ticks_ms
@@ -67,6 +68,13 @@ class Robot:
         self.wdt_feed_timer = Timer(-1)
         self.wdt_feed_timer.init(period=WDT_FEED_TIMER_PERIOD, mode=Timer.PERIODIC,
                                  callback=self.wdt_feed)
+        
+    def storage(self):
+        fs_stat = os.statvfs('/')
+        total = fs_stat[0] * fs_stat[2]  # Block size * Total blocks
+        free = fs_stat[0] * fs_stat[3]   # Block size * Free blocks
+        print(f"Total Flash: {total} bytes")
+        print(f"Free Space: {free} bytes ({free/total*100:.1f}%)")
     
     # Function called with a timer to feed Watch Dog Timer to prevent rebooting
     def wdt_feed(self, t):