micropython: Add examples for memory stats.

doc/main/micropython/micropython.rst

@@ -25,3 +25,24 @@ Using constants for efficiency
 
 .. literalinclude::
     ../../../examples/micropython/const.py
+
+Checking free RAM
+******************************
+
+.. literalinclude::
+    ../../../examples/micropython/memuse.py
+
+This prints information in the format shown below. In this example for the
+SPIKE Prime Hub, there are 257696 bytes (251 KB) worth of memory remaining for
+the variables in your code. ::
+
+    stack: 372 out of 40184
+    GC: total: 258048, used: 352, free: 257696
+    No. of 1-blocks: 4, 2-blocks: 2, max blk sz: 8, max free sz: 16103
+
+
+Getting more memory statistics
+******************************
+
+.. literalinclude::
+    ../../../examples/micropython/memstat.py

examples/micropython/memstat.py

@@ -0,0 +1,29 @@
+from micropython import const, opt_level, mem_info, qstr_info, stack_use
+
+# Get stack at start.
+stack_start = stack_use()
+
+# Print REPL compiler optimization level.
+print("level", opt_level())
+
+# Print memory usage.
+mem_info()
+
+# Print memory usage and a memory map.
+mem_info(True)
+
+# Print interned string information.
+qstr_info()
+
+# Print interned string information and their names.
+APPLES = const(123)
+_ORANGES = const(456)
+qstr_info(True)
+
+
+def test_stack():
+    return stack_use()
+
+
+# Check the stack.
+print("Stack diff: ", test_stack() - stack_start)

examples/micropython/memuse.py

@@ -0,0 +1,4 @@
+from micropython import mem_info
+
+# Print memory usage.
+mem_info()