RAM optimization

platformio.ini

@@ -8,16 +8,44 @@
 ; Please visit documentation for the other options and examples
 ; https://docs.platformio.org/page/projectconf.html
 
-[env:nanoatmega328new]
-platform = atmelavr
-board = nanoatmega328new
-framework = arduino
+[platformio]
+default_envs = nanoatmega328new
+
+; custom common options
+[common]
+build_flags =
+    -D VERSION=1.2.3
+    -D DEBUG=1
+
+lib_deps_external =
 
 [env:megaatmega2560]
 platform = atmelavr
 board = megaatmega2560
 framework = arduino
 
+; Build options
+build_flags =
+    ${common.build_flags}
+    -D DISPLAY_ENABLE
+
+; Library options
+lib_deps =
+    ${common.lib_deps_external}
+    adafruit/Adafruit SSD1306 @ ^2.5.13
+
+[env:nanoatmega328new]
+platform = atmelavr
+board = nanoatmega328new
+framework = arduino
+
+; Build options
+build_flags =
+    ${common.build_flags}
+
+; Library options
+lib_deps =
+    ${common.lib_deps_external}
 
 ;upload_protocol = custom
 ;upload_flags =
@@ -29,8 +57,5 @@ framework = arduino
 ;    -c
 ;    jtag3isp
 ;upload_command = avrdude $UPLOAD_FLAGS -U flash:w:$SOURCE:i
-
 ;extra_scripts = fuses.py
 
-lib_deps =
-    adafruit/Adafruit SSD1306 @ ^2.5.13