diff --git a/build.sh b/build.sh
new file mode 100644
index 0000000..a7e1801
--- /dev/null
+++ b/build.sh
@@ -0,0 +1,4 @@
+avr-gcc -Os -DF_CPU=16000000UL -Wall -Wextra -Wpedantic -Wformat -pedantic-errors -Werror -Wfatal-errors -mmcu=atmega2560 -c -o src/main.o src/main.c
+avr-gcc -mmcu=atmega2560 src/main.o -o bin/atmega2560-user-code.elf
+avr-objcopy -O ihex -R .eeprom bin/atmega2560-user-code.elf bin/atmega2560-user-code.ihx
+avrdude -v -F -V -c stk500v2 -p m2560 -P /dev/ttyACM0 -b 115200 -U flash:w:bin/atmega2560-user-code.ihx
diff --git a/src/main.c b/src/main.c
index e69de29..efad7bf 100644
--- a/src/main.c
+++ b/src/main.c
@@ -0,0 +1,18 @@
+#include <avr/io.h>
+#include <util/delay.h>
+
+#define BLINK_DELAY_MS  1000
+
+int main (void)
+{
+    /*  set pin 25 of PORTB for output*/
+    DDRA |= _BV(DDA3);
+    while(1) {
+        /*  set pin 25 high to turn led on  */
+        PORTA |= _BV(PORTA3);
+        _delay_ms(BLINK_DELAY_MS);
+        /*  set pin 25 low to turn led off */
+        PORTA   &=  ~_BV(PORTA3);
+        _delay_ms(BLINK_DELAY_MS);
+    }
+}