diff --git a/.travis.yml b/.travis.yml
index 0ad107a8..9d3603b5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,6 +7,7 @@ before_install:
   - sudo apt-get -y install build-essential
   - sudo apt-get -y install gcc-arm-none-eabi
   - sudo apt-get -y install libnewlib-arm-none-eabi
+  - sudo apt-get -y install gcc-avr avr-libc binutils-avr
 
 compiler:
   - gcc
@@ -38,3 +39,11 @@ jobs:
       script:
         - make stm32f10x
         - make at91sam7s
+    - stage: ports-avr
+      os: linux
+      before_script:
+        - avr-gcc --version
+      script:
+        - make atmega168
+        - make bdk-atxx4-mstp
+
diff --git a/ports/atmega168/apdu.c b/ports/atmega168/apdu.c
index ec36b041..986d31d0 100644
--- a/ports/atmega168/apdu.c
+++ b/ports/atmega168/apdu.c
@@ -122,6 +122,7 @@ void apdu_handler(
                     handler_unrecognized_service(service_request,
                         service_request_len, src, &service_data);
                 }
+                (void)len;
                 break;
             case PDU_TYPE_UNCONFIRMED_SERVICE_REQUEST:
                 service_choice = apdu[1];
diff --git a/ports/atmega168/h_rp.c b/ports/atmega168/h_rp.c
index b6ba0c8a..ee61b543 100644
--- a/ports/atmega168/h_rp.c
+++ b/ports/atmega168/h_rp.c
@@ -154,6 +154,7 @@ void handler_read_property(
     bytes_sent =
         datalink_send_pdu(src, &npdu_data, &Handler_Transmit_Buffer[0],
         pdu_len);
+    (void)bytes_sent;
 
     return;
 }
diff --git a/ports/atmega168/h_wp.c b/ports/atmega168/h_wp.c
index 2ffa3afa..4fd05c99 100644
--- a/ports/atmega168/h_wp.c
+++ b/ports/atmega168/h_wp.c
@@ -133,6 +133,7 @@ void handler_write_property(
     bytes_sent =
         datalink_send_pdu(src, &npdu_data, &Handler_Transmit_Buffer[0],
         pdu_len);
+    (void)bytes_sent;
 
     return;
 }
diff --git a/ports/atmega168/rs485.c b/ports/atmega168/rs485.c
index 0c8925ac..b203e568 100644
--- a/ports/atmega168/rs485.c
+++ b/ports/atmega168/rs485.c
@@ -260,7 +260,7 @@ bool RS485_ReceiveError(
     void)
 {
     bool ReceiveError = false;
-    uint8_t dummy_data;
+    volatile uint8_t dummy_data;
 
     /* check for framing error */
 #if 0
@@ -281,6 +281,7 @@ bool RS485_ReceiveError(
     if (ReceiveError) {
         RS485_LED1_On();
     }
+    (void)dummy_data;
 
     return ReceiveError;
 }
diff --git a/ports/bdk-atxx4-mstp/Makefile b/ports/bdk-atxx4-mstp/Makefile
index e44fe7bb..5933554f 100644
--- a/ports/bdk-atxx4-mstp/Makefile
+++ b/ports/bdk-atxx4-mstp/Makefile
@@ -67,8 +67,9 @@ AVRDUDE_PORT := /dev/ttyUSB0
 endif
 
 # Source locations
-BACNET_CORE = ../../src
-BACNET_INCLUDE = $(BACNET_CORE)
+BACNET_SRC = ../../src
+BACNET_CORE = $(BACNET_SRC)/bacnet
+BACNET_INCLUDE = $(BACNET_SRC)
 BACNET_BASIC = $(BACNET_CORE)/basic
 
 # local files for this project
diff --git a/src/bacnet/basic/sys/mstimer.c b/src/bacnet/basic/sys/mstimer.c
index 92a07b72..206e287e 100644
--- a/src/bacnet/basic/sys/mstimer.c
+++ b/src/bacnet/basic/sys/mstimer.c
@@ -20,7 +20,6 @@
 #include <stdio.h>
 #include <stdbool.h>
 #include <stdint.h>
-#include <time.h>
 #include "mstimer.h"
 
 /**
@@ -83,12 +82,12 @@ void mstimer_restart(struct mstimer *t)
  * @return Non-zero if the timer has expired, zero otherwise.
  */
 int mstimer_expired(struct mstimer *t)
-{ 
+{
     if (t->interval) {
         return ((unsigned long)((mstimer_now()) - (t->start + t->interval)) <
             ((unsigned long)(~((unsigned long)0)) >> 1));
     }
-    
+
     return 0;
 }
 /*---------------------------------------------------------------------------*/