Constants shouldn't be uppercase

Makefile

@@ -8,6 +8,7 @@ CC = avr-gcc
 OBJCOPY = avr-objcopy
 AVRDUDE = avrdude
 CODE_FORMATTER = tooling/format-code.sh
+AVRSIZE = avr-size
 
 BOARD = atmega2560
 
@@ -42,13 +43,18 @@ CFLAGS =	-Wall \
 			-Werror \
 			-Wfatal-errors \
 			-Os \
+			-flto \
+			-fdata-sections \
+			-ffunction-sections \
 			-mmcu=$(BOARD) \
 			-DF_CPU=16000000UL \
 			-DGIT_DESCR=\"$(shell git describe --abbrev=6 --dirty --always --tags --long)\" \
 			-std=c11
 
 # Linker flags
-LDFLAGS = -mmcu=$(BOARD)
+LDFLAGS =	-mmcu=$(BOARD) \
+			-flto \
+			-Wl,-gc-sections
 
 OBJCOPYARGS =	-O ihex \
 				-R .eeprom
@@ -62,6 +68,9 @@ AVRDUDEARGS =	-p $(BOARD) \
 				-V \
 				-D
 
+AVRSIZEARGS =	-C \
+				--mcu=$(BOARD)
+
 all: $(ELF) $(TARGET)
 
 %.o : %.c
@@ -83,6 +92,9 @@ install:
 	$(AVRDUDE) $(AVRDUDEARGS) -U flash:w:$(TARGET)
 
 format:
-	$(CODE_FORMATTER) $(SRC)
+	$(CODE_FORMATTER) $(SRCDIR)/*.c
 
-.PHONY: clean install format
+size:
+	$(AVRSIZE) $(AVRSIZEARGS) $(ELF)
+
+.PHONY: clean install format size

src/hmi_msg.h

@@ -2,17 +2,17 @@
 #ifndef _HMI_MSG_H_
 #define _HMI_MSG_H_
 
-const char PROG_VERSION[]  PROGMEM = "Version: %s built on: %s %s\n";
-const char LIBC_VERSION[]  PROGMEM = "avr-libc version: %s\n";
-const char STUD_NAME[]     PROGMEM = "Arti Zirk";
-const char GET_MONTH_MSG[] PROGMEM = "Enter Month name first letter >";
-const char ENG_MONTH[6][9] PROGMEM = {
-                                        "January",
-                                        "February",
-                                        "March",
-                                        "April",
-                                        "May",
-                                        "June",
-                                      };
+#define PROG_VERSION "Version: %S built on: %S %S\n"
+#define LIBC_VERSION "avr-libc version: %S\n"
+#define STUD_NAME "Arti Zirk"
+#define GET_MONTH_MSG "Enter Month name first letter >"
 
+const char m1[]  PROGMEM = "January";
+const char m2[] PROGMEM = "February";
+const char m3[]    PROGMEM = "March";
+const char m4[]    PROGMEM = "April";
+const char m5[]      PROGMEM = "May";
+const char m6[]     PROGMEM = "June";
+
+PGM_P const months[] PROGMEM = {m1,m2,m3,m4,m5,m6};
 #endif /* _HMI_MSG_H_ */

src/main.c

@@ -23,18 +23,18 @@ int main (void)
     /* End init */
 
     /* Print version info to stderr */
-    fprintf_P(stderr, PROG_VERSION, GIT_DESCR, __DATE__, __TIME__);
-    fprintf_P(stderr, LIBC_VERSION, __AVR_LIBC_VERSION_STRING__);
+    fprintf_P(stderr, PSTR(PROG_VERSION),
+              PSTR(GIT_DESCR), PSTR(__DATE__), PSTR(__TIME__));
+    fprintf_P(stderr, PSTR(LIBC_VERSION), PSTR(__AVR_LIBC_VERSION_STRING__));
     /* End version print */
 
-    fprintf_P(stdout, STUD_NAME);
+    fprintf_P(stdout, PSTR(STUD_NAME));
     fputc('\n', stdout); /* Add a new line to the uart printout */
-    lcd_puts_P(STUD_NAME);
-    lcd_goto(0x40); /* Got to the beginning of the next line */
+    lcd_puts_P(PSTR(STUD_NAME));
 
     /* ASCII table print */
     print_ascii_tbl(stdout);
-    unsigned char ascii[128] = {0};
+    unsigned char ascii[128];
     for (unsigned char i = 0; i < sizeof(ascii); i++) {
         ascii[i] = i;
     }
@@ -46,21 +46,21 @@ int main (void)
         _delay_ms(BLINK_DELAY_MS);
 
         /* Month search and print */
-        char month_first_leter;
-        fprintf_P(stdout, GET_MONTH_MSG);
-        fscanf(stdin, "%c", &month_first_leter);
-        fprintf(stdout, "%c\n", month_first_leter);
+        char letter;
+        fprintf_P(stdout, PSTR(GET_MONTH_MSG));
+        fscanf(stdin, "%c", &letter);
+        fprintf(stdout, "%c\n", letter);
+        lcd_goto(0x40); /* Got to the beginning of the next line */
         for (int i = 0; i < 6; i++) {
-            if (!strncmp_P(&month_first_leter, ENG_MONTH[i], 1)) {
-                fprintf_P(stdout, ENG_MONTH[i]);
+            if (!strncmp_P(&letter, (PGM_P)pgm_read_word(&months[i]), 1)) {
+                fprintf_P(stdout, (PGM_P)pgm_read_word(&months[i]));
                 fputc('\n', stdout);
-                lcd_puts_P(ENG_MONTH[i]);
+                lcd_puts_P((PGM_P)pgm_read_word(&months[i]));
                 lcd_putc(' ');
             }
         }
-        lcd_puts_P(PSTR("                ")); /* Clear the end of the line */
-        lcd_goto(0x40); /* Got to the beginning of the next line */
 
+        lcd_puts_P(PSTR("                ")); /* Clear the end of the line */
 
         /* set pin 3 low to turn led off */
         PORTA &= ~_BV(PORTA3);

src/print_helper.c

@@ -1,27 +1,33 @@
 #include <stdio.h>
+#include <avr/pgmspace.h>
 #include "print_helper.h"
 
-int print_ascii_tbl (FILE *stream) {
+int print_ascii_tbl (FILE *stream)
+{
     for (char c = ' '; c <= '~'; c++) {
         if (!fprintf(stream, "%c ", c)) {
             return 0;
         }
     }
+
     return fprintf(stream, "\n");
 }
 
 
-int print_for_human (FILE *stream, const unsigned char *array, const int len) {
+int print_for_human (FILE *stream, const unsigned char *array, const int len)
+{
     for (int i = 0; i < len; i++) {
-        if (array[i] >= ' ' && array[i] <= '~') {
-            if(!fprintf(stream, "%c", array[i])) {
+        unsigned char c = array[i];
+        if (c >= ' ' && c <= '~') {
+            if (!fprintf(stream, "%c", c)) {
                 return 0;
             }
         } else {
-            if(!fprintf(stream, "\"0x%02x\"", array[i])) {
+            if (!fprintf(stream, "\"0x%02x\"", c)) {
                 return 0;
             }
         }
     }
-    return fprintf(stream, "\n");;
+
+    return fprintf(stream, "\n");
 }

tooling/format-code.sh

@@ -18,10 +18,8 @@ for FILE in "$@"
 do
     RESULT="$(astyle    --style=1tbs \
                         --indent-col1-comments \
-                        --break-blocks \
                         --pad-oper \
                         --pad-header \
-                        --delete-empty-lines \
                         --add-brackets \
                         --convert-tabs \
                         --max-code-length=80 \