Add Python script for generating code.

py/atten_levels.py

@@ -0,0 +1,13 @@
+lvls = [.75, 1.5, 3, 6, 12, 24]
+
+def get_db(i):
+	db = 0.0
+	for d in lvls:
+		if i & 0x1:
+			db += d
+		i >>= 1
+	return db
+
+for i in range(2**6):
+	db = get_db(i)
+	print '"%.2f dB",' % db,