Fix pgmspace casting

Author: ianfixes

CHANGELOG.md

@@ -12,9 +12,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Deprecated
 
 ### Removed
-* Unnecessary board changes during unit tests no longer happen
+- Unnecessary board changes during unit tests no longer happen
 
 ### Fixed
+- Proper casting for `pgm_read_byte`
 
 ### Security
 

cpp/arduino/avr/pgmspace.h

@@ -42,7 +42,7 @@ out.each { |l| puts d(l) }
 #define pgm_read_ptr_far(x)   (x)
 
 
-#define pgm_read_byte(x) (x)
+#define pgm_read_byte(addr) (*(const uint8_t *)(addr))
 #define pgm_read_word(x) (x)
 #define pgm_read_dword(x) (x)
 #define pgm_read_float(x) (x)