diff --git a/controller/controller.c b/controller/controller.c
index 5cc0703..75f11c6 100644
--- a/controller/controller.c
+++ b/controller/controller.c
@@ -16,7 +16,6 @@
 
 #define IIC_DEVICE "/dev/i2c-7"
 #define BUFFER_BLOCKS 128
-#define BUFFER_DATA_SIZE 8
 
 #define HEADING_SIM_UP "sim/autopilot/heading_up"
 #define HEADING_SIM_DOWN "sim/autopilot/heading_down"
@@ -31,7 +30,7 @@ struct ringBuffer i2cDataRead;
 struct ringBuffer i2cDataWrite;
 
 struct blockData {
-  char data[BUFFER_DATA_SIZE];
+  char data[DATA_SIZE];
   int triggerBit;
 };
 
diff --git a/controller/global.h b/controller/global.h
index 536b060..99ceb2d 100644
--- a/controller/global.h
+++ b/controller/global.h
@@ -8,3 +8,4 @@
 #define TRIGGER_BIT_2 4
 #define HIGH_BIT_2 8
 #define I2C_ADDRESS_START 0x08
+#define DATA_SIZE 8
diff --git a/rotator/rotator.ino b/rotator/rotator.ino
index e796b4b..ef17d9d 100644
--- a/rotator/rotator.ino
+++ b/rotator/rotator.ino
@@ -51,6 +51,11 @@ uint8_t lastClk = HIGH;
 byte valueBuffer[VALUE_BUFFER] = { 0 };
 uint8_t readerPos, writerPos = 0;
 
+// ringbuffer of display data
+struct {
+  
+}
+
 void addValue(uint8_t value) {
   valueBuffer[writerPos++] = value;