diff --git a/bacnet-stack/ai.c b/bacnet-stack/ai.c
index 1e11205f..c351c69e 100644
--- a/bacnet-stack/ai.c
+++ b/bacnet-stack/ai.c
@@ -96,11 +96,12 @@ int Analog_Input_Encode_Property_APDU(
       apdu_len = encode_tagged_real(&apdu[0], value);
       break;
     case PROP_STATUS_FLAGS:
-        bitstring_set_bit(&bit_string, STATUS_FLAG_IN_ALARM, false);
-        bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, false);
-        bitstring_set_bit(&bit_string, STATUS_FLAG_OVERRIDDEN, false);
-        bitstring_set_bit(&bit_string, STATUS_FLAG_OUT_OF_SERVICE, false);
-        apdu_len = encode_tagged_bitstring(&apdu[0], &bit_string);
+      bitstring_init(&bit_string);
+      bitstring_set_bit(&bit_string, STATUS_FLAG_IN_ALARM, false);
+      bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, false);
+      bitstring_set_bit(&bit_string, STATUS_FLAG_OVERRIDDEN, false);
+      bitstring_set_bit(&bit_string, STATUS_FLAG_OUT_OF_SERVICE, false);
+      apdu_len = encode_tagged_bitstring(&apdu[0], &bit_string);
       break;
     case PROP_EVENT_STATE:
       apdu_len = encode_tagged_enumerated(&apdu[0],EVENT_STATE_NORMAL);
diff --git a/bacnet-stack/ao.c b/bacnet-stack/ao.c
index 1e17ea24..b63f5eb6 100644
--- a/bacnet-stack/ao.c
+++ b/bacnet-stack/ao.c
@@ -181,11 +181,12 @@ int Analog_Output_Encode_Property_APDU(
       apdu_len = encode_tagged_real(&apdu[0], real_value);
       break;
     case PROP_STATUS_FLAGS:
-        bitstring_set_bit(&bit_string, STATUS_FLAG_IN_ALARM, false);
-        bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, false);
-        bitstring_set_bit(&bit_string, STATUS_FLAG_OVERRIDDEN, false);
-        bitstring_set_bit(&bit_string, STATUS_FLAG_OUT_OF_SERVICE, false);
-        apdu_len = encode_tagged_bitstring(&apdu[0], &bit_string);
+      bitstring_init(&bit_string);
+      bitstring_set_bit(&bit_string, STATUS_FLAG_IN_ALARM, false);
+      bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, false);
+      bitstring_set_bit(&bit_string, STATUS_FLAG_OVERRIDDEN, false);
+      bitstring_set_bit(&bit_string, STATUS_FLAG_OUT_OF_SERVICE, false);
+      apdu_len = encode_tagged_bitstring(&apdu[0], &bit_string);
       break;
     case PROP_EVENT_STATE:
       apdu_len = encode_tagged_enumerated(&apdu[0],EVENT_STATE_NORMAL);
diff --git a/bacnet-stack/bacapp.c b/bacnet-stack/bacapp.c
index 8ce0c11d..b2ff1229 100644
--- a/bacnet-stack/bacapp.c
+++ b/bacnet-stack/bacapp.c
@@ -267,18 +267,11 @@ bool bacapp_compare(
           test_length = characterstring_length(&test_value->type.Character_String);
           test_str = characterstring_value(&test_value->type.Character_String);
           if (length != test_length)
-          {
             status = false;
-            printf("length=%d test_length=%d\n",length,test_length);
-          }
           for (i = 0; i < test_length; i++)
           {
             if (str[i] != test_str[i])
-            {
               status = false;
-              printf("str[%d]=%c test_str[%d]=%c\n",
-                i,str[i],i,test_str[i]);
-            }
           }
         }
         break;
diff --git a/bacnet-stack/bacdcode.c b/bacnet-stack/bacdcode.c
index 7a50bcb1..821140a9 100644
--- a/bacnet-stack/bacdcode.c
+++ b/bacnet-stack/bacdcode.c
@@ -596,36 +596,17 @@ int decode_bitstring(uint8_t * apdu, uint32_t len_value,
         len = 1;
         for (i = 0; i < bytes_used; i++)
         {
-              bit_string->value[i] = byte_reverse_bits(apdu[len++]);
+          bitstring_set_octet(bit_string, i, byte_reverse_bits(apdu[len++]));
         }
         unused_bits = apdu[0] & 0x07;
-        bit_string->bits_used = (uint8_t)(bytes_used * 8);
-        bit_string->bits_used -= unused_bits;
+        bitstring_set_bits_used(bit_string,
+           (uint8_t)bytes_used, unused_bits);
       }
     }
 
     return len;
 }
 
-// returns the number of bytes that a bit string is using
-static int bitstring_bytes_used(BACNET_BIT_STRING *bit_string)
-{
-  int len = 0; // return value
-  uint8_t used_bytes = 0;
-  uint8_t last_bit = 0;
-
-  if (bit_string->bits_used)
-  {
-    last_bit = bit_string->bits_used - 1;
-    used_bytes = last_bit / 8;
-    // add one for the first byte
-    used_bytes++;
-    len = used_bytes;
-  }
-
-  return len;
-}
-
 // from clause 20.2.10 Encoding of a Bit String Value
 // returns the number of apdu bytes consumed
 int encode_bitstring(uint8_t * apdu, BACNET_BIT_STRING *bit_string)
@@ -636,17 +617,18 @@ int encode_bitstring(uint8_t * apdu, BACNET_BIT_STRING *bit_string)
     uint8_t i = 0;
 
     // if the bit string is empty, then the first octet shall be zero
-    if (bit_string->bits_used == 0)
+    if (bitstring_bits_used(bit_string) == 0)
       apdu[len++] = 0;
     else
     {
       used_bytes = bitstring_bytes_used(bit_string);
-      remaining_used_bits = bit_string->bits_used - ((used_bytes - 1) * 8);
+      remaining_used_bits = bitstring_bits_used(bit_string) -
+          ((used_bytes - 1) * 8);
       // number of unused bits in the subsequent final octet
       apdu[len++] = 8 - remaining_used_bits;
       for (i = 0; i < used_bytes; i++)
       {
-        apdu[len++] = byte_reverse_bits(bit_string->value[i]);
+        apdu[len++] = byte_reverse_bits(bitstring_octet(bit_string,i));
       }
     }
 
diff --git a/bacnet-stack/bacstr.c b/bacnet-stack/bacstr.c
index a9b5f84d..bad1eb53 100644
--- a/bacnet-stack/bacstr.c
+++ b/bacnet-stack/bacstr.c
@@ -88,6 +88,78 @@ uint8_t bitstring_bits_used(BACNET_BIT_STRING *bit_string)
   return bit_string->bits_used;
 }
 
+// returns the number of bytes that a bit string is using
+int bitstring_bytes_used(BACNET_BIT_STRING *bit_string)
+{
+  int len = 0; // return value
+  uint8_t used_bytes = 0;
+  uint8_t last_bit = 0;
+
+  if (bit_string->bits_used)
+  {
+    last_bit = bit_string->bits_used - 1;
+    used_bytes = last_bit / 8;
+    // add one for the first byte
+    used_bytes++;
+    len = used_bytes;
+  }
+
+  return len;
+}
+
+uint8_t bitstring_octet(BACNET_BIT_STRING *bit_string, uint8_t index)
+{
+  uint8_t octet = 0;
+
+  if (bit_string)
+  {
+    if (index < MAX_BITSTRING_BYTES)
+    {
+      octet = bit_string->value[index];
+    }
+  }
+
+  return octet;
+}
+
+bool bitstring_set_octet(
+    BACNET_BIT_STRING *bit_string,
+    uint8_t index,
+    uint8_t octet)
+{
+  bool status = false;
+
+  if (bit_string)
+  {
+    if (index < MAX_BITSTRING_BYTES)
+    {
+      bit_string->value[index] = octet;
+      status = true;
+    }
+  }
+
+  return status;
+}
+
+bool bitstring_set_bits_used(
+  BACNET_BIT_STRING *bit_string,
+  uint8_t bytes_used,
+  uint8_t unused_bits)
+{
+  bool status = false;
+
+  if (bit_string)
+  {
+    /* FIXME: check that bytes_used is at least one? */
+    bit_string->bits_used = bytes_used * 8;
+    bit_string->bits_used -= unused_bits;
+    status = true;
+  }
+
+  return status;
+}
+
+
 uint8_t bitstring_bits_capacity(BACNET_BIT_STRING *bit_string)
 {
   if (bit_string)
diff --git a/bacnet-stack/bacstr.h b/bacnet-stack/bacstr.h
index 9f79d773..9ae9951b 100644
--- a/bacnet-stack/bacstr.h
+++ b/bacnet-stack/bacstr.h
@@ -73,7 +73,19 @@ void bitstring_init(BACNET_BIT_STRING *bit_string);
 void bitstring_set_bit(BACNET_BIT_STRING *bit_string, uint8_t bit, bool value);
 bool bitstring_bit(BACNET_BIT_STRING *bit_string, uint8_t bit);
 uint8_t bitstring_bits_used(BACNET_BIT_STRING *bit_string);
+// returns the number of bytes that a bit string is using
+int bitstring_bytes_used(BACNET_BIT_STRING *bit_string);
 uint8_t bitstring_bits_capacity(BACNET_BIT_STRING *bit_string);
+/* used for encoding and decoding from the APDU */
+uint8_t bitstring_octet(BACNET_BIT_STRING *bit_string, uint8_t octet_index);
+bool bitstring_set_octet(
+  BACNET_BIT_STRING *bit_string,
+  uint8_t index,
+  uint8_t octet);
+bool bitstring_set_bits_used(
+  BACNET_BIT_STRING *bit_string,
+  uint8_t bytes_used,
+  uint8_t unused_bits);
 
 /* returns false if the string exceeds capacity
    initialize by using length=0 */