Add comments for Aloha (#417)

Co-authored-by: Simon Alibert <75076266+aliberts@users.noreply.github.com>

lerobot/common/robot_devices/utils.py

@@ -1,13 +1,19 @@
+import platform
 import time
 
 
 def busy_wait(seconds):
-    # Significantly more accurate than `time.sleep`, and mandatory for our use case,
-    # but it consumes CPU cycles.
-    # TODO(rcadene): find an alternative: from python 11, time.sleep is precise
-    end_time = time.perf_counter() + seconds
-    while time.perf_counter() < end_time:
-        pass
+    if platform.system() == "Darwin":
+        # On Mac, `time.sleep` is not accurate and we need to use this while loop trick,
+        # but it consumes CPU cycles.
+        # TODO(rcadene): find an alternative: from python 11, time.sleep is precise
+        end_time = time.perf_counter() + seconds
+        while time.perf_counter() < end_time:
+            pass
+    else:
+        # On Linux time.sleep is accurate
+        if seconds > 0:
+            time.sleep(seconds)
 
 
 class RobotDeviceNotConnectedError(Exception):