diff --git a/blink/blink.elf b/blink/blink.elf
index fc580c2..0420267 100644
Binary files a/blink/blink.elf and b/blink/blink.elf differ
diff --git a/blink/blink.hex b/blink/blink.hex
index 09fc6c7..b6beb9a 100644
--- a/blink/blink.hex
+++ b/blink/blink.hex
@@ -5,8 +5,8 @@
 :100040000C943E000C943E000C943E000C943E0038
 :100050000C943E000C943E000C943E000C943E0028
 :100060000C943E000C943E0011241FBECFEFD4E050
-:10007000DEBFCDBF0E9440000C9451000C940000E4
-:10008000209A81E085B9E7EAF1E63197F1F700C0FF
-:10009000000015B8E7EAF1E63197F1F700C000007B
-:0600A000F1CFF894FFCF40
+:10007000DEBFCDBF0E9440000C9454000C940000E1
+:10008000209A81E085B9E3EDF0E33197F1F700C004
+:10009000000015B8FFE32DE033E0F1502040304080
+:0C00A000E1F700C00000EECFF894FFCFA5
 :00000001FF
diff --git a/blink/blink.map b/blink/blink.map
index a883591..287e578 100644
--- a/blink/blink.map
+++ b/blink/blink.map
@@ -222,7 +222,7 @@ END GROUP
 .rela.plt
  *(.rela.plt)
 
-.text           0x0000000000000000       0xa6
+.text           0x0000000000000000       0xac
  *(.vectors)
  .vectors       0x0000000000000000       0x68 c:/users/emanuel/apps/avr8-gnu-toolchain-3.7.0.1796-win32.any.x86_64/avr8-gnu-toolchain-win32_x86_64/bin/../lib/gcc/avr/7.3.0/../../../../avr/lib/avr5/crtatmega168.o
                 0x0000000000000000                __vector_default
@@ -306,13 +306,13 @@ END GROUP
                 0x0000000000000080                . = ALIGN (0x2)
  *(.text.*)
  .text.startup.main
-                0x0000000000000080       0x22 blinkled.o
+                0x0000000000000080       0x28 blinkled.o
                 0x0000000000000080                main
-                0x00000000000000a2                . = ALIGN (0x2)
+                0x00000000000000a8                . = ALIGN (0x2)
  *(.fini9)
- .fini9         0x00000000000000a2        0x0 c:/users/emanuel/apps/avr8-gnu-toolchain-3.7.0.1796-win32.any.x86_64/avr8-gnu-toolchain-win32_x86_64/bin/../lib/gcc/avr/7.3.0/avr5\libgcc.a(_exit.o)
-                0x00000000000000a2                _exit
-                0x00000000000000a2                exit
+ .fini9         0x00000000000000a8        0x0 c:/users/emanuel/apps/avr8-gnu-toolchain-3.7.0.1796-win32.any.x86_64/avr8-gnu-toolchain-win32_x86_64/bin/../lib/gcc/avr/7.3.0/avr5\libgcc.a(_exit.o)
+                0x00000000000000a8                _exit
+                0x00000000000000a8                exit
  *(.fini9)
  *(.fini8)
  *(.fini8)
@@ -331,11 +331,11 @@ END GROUP
  *(.fini1)
  *(.fini1)
  *(.fini0)
- .fini0         0x00000000000000a2        0x4 c:/users/emanuel/apps/avr8-gnu-toolchain-3.7.0.1796-win32.any.x86_64/avr8-gnu-toolchain-win32_x86_64/bin/../lib/gcc/avr/7.3.0/avr5\libgcc.a(_exit.o)
+ .fini0         0x00000000000000a8        0x4 c:/users/emanuel/apps/avr8-gnu-toolchain-3.7.0.1796-win32.any.x86_64/avr8-gnu-toolchain-win32_x86_64/bin/../lib/gcc/avr/7.3.0/avr5\libgcc.a(_exit.o)
  *(.fini0)
-                0x00000000000000a6                _etext = .
+                0x00000000000000ac                _etext = .
 
-.data           0x0000000000800100        0x0 load address 0x00000000000000a6
+.data           0x0000000000800100        0x0 load address 0x00000000000000ac
                 [!provide]                        PROVIDE (__data_start, .)
  *(.data)
  *(.data*)
@@ -353,8 +353,8 @@ END GROUP
  *(.bss*)
  *(COMMON)
                 [!provide]                        PROVIDE (__bss_end, .)
-                0x00000000000000a6                __data_load_start = LOADADDR (.data)
-                0x00000000000000a6                __data_load_end = (__data_load_start + SIZEOF (.data))
+                0x00000000000000ac                __data_load_start = LOADADDR (.data)
+                0x00000000000000ac                __data_load_end = (__data_load_start + SIZEOF (.data))
 
 .noinit         0x0000000000800100        0x0
                 [!provide]                        PROVIDE (__noinit_start, .)
@@ -458,9 +458,9 @@ END GROUP
  .debug_str     0x0000000000000208      0x17c blinkled.o
                                         0x1b0 (size before relaxing)
 
-.debug_loc      0x0000000000000000       0x48
+.debug_loc      0x0000000000000000       0x46
  *(.debug_loc)
- .debug_loc     0x0000000000000000       0x48 blinkled.o
+ .debug_loc     0x0000000000000000       0x46 blinkled.o
 
 .debug_macinfo
  *(.debug_macinfo)
diff --git a/blink/blinkled.c b/blink/blinkled.c
index 9f48132..594f721 100644
--- a/blink/blinkled.c
+++ b/blink/blinkled.c
@@ -5,15 +5,28 @@
 int main(void)
 {
 
-    // set the lowest order bit 
+    /*
+    the DDRX registers are used to indicated whether each pin 
+    is being used for input or output (data direction)
+    to enable a pin as output you set its corresponding bit to 1, 
+    the default state is 0 (input)
+    */ 
     DDRB |= 0b00000001;
 
     while (1) {
+
+        /* 
+        When DDRx is set to 1 (output):
+        PORTx controls whether that port register is set to high or low. 
+        
+        When DDRx is set to 0 (input) it is essentially disconnected
+        from the circuit
+        */
         PORTB = 0b00000001; // turn on the LED
-        _delay_ms(100);
+        _delay_ms(50);
 
         PORTB = 0b00000000;
-        _delay_ms(100);
+        _delay_ms(1000);
     
     }
 
diff --git a/blink/blinkled.o b/blink/blinkled.o
index f5a6529..6ba8147 100644
Binary files a/blink/blinkled.o and b/blink/blinkled.o differ