diff --git a/ssd1306.h b/ssd1306.h
--- a/ssd1306.h
+++ b/ssd1306.h
@@ -19,7 +19,9 @@
 
 void ssd1306_Init(void);
 void ssd1306_DrawChar(char ascii, unsigned char row, unsigned char xPos);
+void ssd1306_DrawCharBig(char ascii, unsigned char row, unsigned char xPos);
 void ssd1306_DrawString(const char *dataPtr, unsigned char row, unsigned char xPos);
+void ssd1306_DrawStringBig(const char *dataPtr, unsigned char row, unsigned char xPos);
 void ssd1306_drawlogo();
 void ssd1306_clearscreen();