diff --git a/src/io.s b/src/io.s
index fae5132..6af48f7 100644
--- a/src/io.s
+++ b/src/io.s
@@ -1,6 +1,43 @@
+//---------Local variables ----------------------
+.data
+
+
+
+/*
+typedef struct pin_s {
+    GPIO_TypeDef* GPIO;
+    uint16_t pinmask;
+} pin_t;
+*/
+
+.set OFFSET_PIN_GPIO, 0
+.set OFFSET_PIN_PINMASK, 8
+
+
+/*
+static pin_t pin_t0;
+static pin_t pin_t1;
+static pin_t pin_t2;
+static pin_t pin_t3;
+*/
+
+
+pin0: .space 8, 0 //storage for GPIO ptr
+.hword 0 //storage for pinmask
+pin1: .space 8, 0
+.hword 0
+pin2: .space 8, 0
+.hword 0
+pin3: .space 8, 0
+.hword 0
+
+
 
     
 //--------Local Functions ------------------ 
+.text
+
+
 //void pin_create(pin_t* pin, GPIO_TypeDef* GPIO, uint8_t pinnr)
 
 //R0: address to pin struct, R1: address to GPIO, R2: pinnr (1 byte). No return value
@@ -10,33 +47,50 @@ pin_create:
     .set OFFSET_OTYPER, 0x4
     .set OFFSET_PUPDR, 0xC 
     .set GPIO_MODE_IN, 0
+    .set GPIO_PuPd_UP, 1
+    .set GPIO_OType_OD, 1
 
-    MOV r5, #3 //r5 = 3
     LSL r4, r2, #1 //r4 = pinnr*2
+    MOV r5, #3 //r5 = 3
     LSL r5, r5, r4 //r5 = 3 << (pinnr*2)
 
     //GPIO->MODER &=~ ( 3 << (pinnr*2)); //Clear the 2 bits (mode)
-    LDR r3, [r1, #OFFSET_MODR] //r3 = GPIO->MODR 
+    LDRB r3, [r1, #OFFSET_MODR] //r3 = GPIO->MODR 
     BIC r3, r3, r5 //r3 &= ~r5
 
     //GPIO->MODER |= GPIO_Mode_IN << (pinnr*2); //Set the correct bits for mode
-    MOV r5, #GPIO_MODE_IN
-    LSL r5, r5, r4 //r5 = GPIO_MODE_IN << (pinnr*2) 
-    ORR r3, r3, r5 //r3 |= r5
-    STR r3, [r1, #OFFSET_MODR] //GPIO->MODR = r3
+    MOV r6, #GPIO_MODE_IN
+    LSL r6, r6, r4 //r5 = GPIO_MODE_IN << (pinnr*2) 
+    ORR r3, r3, r6 //r3 |= r6
+    STRB r3, [r1, #OFFSET_MODR] //GPIO->MODR = r3
 
-    //GPIO->OTYPER &=~ (1 << (pinnr*2)); //Clear the bit (otype)
+    //GPIO->PUPDR &=~  (3 <<(pinnr*2)); //clear the 2 bits (pp/od)
+    LDRB r3, [r1, #OFFSET_PUPDR] //r3 = GPIO->PUPDR 
+    BIC r3, r3, r5 //r3 &= ~r5
+
+    //GPIO->PUPDR |= GPIO_PuPd_UP <<(pinnr*2); //set the correct bits for pp/od
+    MOV r6, #GPIO_PuPd_UP
+    LSL r6, r6, r4 //r6 = GPIO_PuPd_UP << (pinnr*2) 
+    ORR r3, r3, r6 //r3 |= r6
+    STRB r3, [r1, #OFFSET_PUPDR] //GPIO->PUPDR = r3
     
+    //GPIO->OTYPER &=~ (1 << pinnr); //Clear the bit (otype)
+    LDRB r3, [r1, #OFFSET_OTYPER] //r3 = GPIO->OTYPER
+    MOV r5, #1 //r5 = 1
+    LSL r5, r5, r2 //r5 = 1 << pinnr
+    BIC r3, r3, r5 //r3 &= ~r5
     
     //GPIO->OTYPER |= GPIO_OType_OD <<(pinnr*2); //set the correct bit for otype
-/*    
-    GPIO->PUPDR &=~  (3 <<(pinnr*2)); //clear the 2 bits (pp/od)
-    GPIO->PUPDR |= GPIO_PuPd_UP <<(pinnr*2); //set the correct bits for pp/od
+    MOV r6, #GPIO_OType_OD
+    LSL r6, r6, r2 //r6 = GPIO_OType_OD << pinnr 
+    ORR r3, r3, r6 //r3 |= r6
+    STRB r3, [r1, #OFFSET_OTYPER] //GPIO->OTYPER = r3
 
-    pin->GPIO=GPIO; // Set the gpiopin in the pin structure
-    pin->pinmask=0x01<<pinnr; // Insert the pinmask
-*/
+    //pin->GPIO=GPIO; // Set the gpiopin in the pin structure
+    STR r1, [r0, #OFFSET_PIN_GPIO]
 
+    //pin->pinmask=0x01<<pinnr; // Insert the pinmask
+    STR r5, [r0, #OFFSET_PIN_PINMASK]
 
 
     //TODO: Implement