Add .hex rule

apps/led1/Makefile

@@ -43,6 +43,11 @@ led1.out: led1.o pio.o system.o timer.o led.o pacer.o
 	$(SIZE) $@
 
 
+# Create hex file for programming from executable file.
+led1.hex: led1.out
+	$(OBJCOPY) -O ihex led1.out led1.hex
+
+
 # Target: clean project.
 .PHONY: clean
 clean: 
@@ -51,8 +56,7 @@ clean:
 
 # Target: program project.
 .PHONY: program
-program: led1.out
-	$(OBJCOPY) -O ihex led1.out led1.hex
+program: led1.hex
 	dfu-programmer atmega32u2 erase; dfu-programmer atmega32u2 flash led1.hex; dfu-programmer atmega32u2 start
 
 

apps/led1/led1.c

@@ -1,6 +1,7 @@
 /** @file   led1.c
     @author M.P. Hayes
     @date   5 Oct 2010
+    @descr  This flashes the LED twice per second.
 */
 
 #include "system.h"
@@ -8,11 +9,14 @@
 #include "pacer.h"
 
 
-/* Define polling rate in Hz.  */
+/* Define polling rate in Hz.  (Note, this is much faster than
+ needed for this application.)  */
 #define LOOP_RATE 1000
 
+/* LED flash rate (Hz).  */
 #define LED_RATE 2
 
+
 int main (void)
 {
     unsigned int count = 0;