diff --git a/examples/c++/relay.cxx b/examples/c++/relay.cxx
index 2aadc8ac..a44d6a2b 100644
--- a/examples/c++/relay.cxx
+++ b/examples/c++/relay.cxx
@@ -24,7 +24,7 @@
 
 #include <unistd.h>
 #include <iostream>
-#include "grove.hpp"
+#include "relay.hpp"
 
 int
 main(int argc, char **argv)
diff --git a/examples/c++/rotary.cxx b/examples/c++/rotary.cxx
index eecd8b2a..2d92982d 100644
--- a/examples/c++/rotary.cxx
+++ b/examples/c++/rotary.cxx
@@ -25,7 +25,7 @@
 #include <unistd.h>
 #include <iostream>
 #include <iomanip>
-#include "grove.hpp"
+#include "rotary.hpp"
 
 using namespace std;
 
diff --git a/examples/c/o2.c b/examples/c/o2.c
index 3fed7555..c8f6a42b 100644
--- a/examples/c/o2.c
+++ b/examples/c/o2.c
@@ -59,7 +59,7 @@ int main()
         o2_get_raw_volts(sensor, &raw_volts);
         o2_get_value(sensor, &o2_percent);
 
-        printf("O2 raw volts: %0.03f v, o2: %0.03f %\n",
+        printf("O2 raw volts: %0.03f v, o2: %0.03f %%\n",
                 raw_volts, o2_percent);
 
         usleep(500000);
diff --git a/src/emg/emg.c b/src/emg/emg.c
index 30730f58..467ef243 100644
--- a/src/emg/emg.c
+++ b/src/emg/emg.c
@@ -94,6 +94,7 @@ upm_result_t emg_get_normalized(const emg_context dev, float *value)
     *value = mraa_aio_read_float(dev->aio);
     if (*value < 0)
         return UPM_ERROR_OPERATION_FAILED;
+    return UPM_SUCCESS;
 }
 
 upm_result_t emg_get_raw_volts(const emg_context dev, float *value)
diff --git a/src/flex/flex.c b/src/flex/flex.c
index ca44a8e1..df658df7 100644
--- a/src/flex/flex.c
+++ b/src/flex/flex.c
@@ -94,6 +94,7 @@ upm_result_t flex_get_normalized(const flex_context dev, float *value)
     *value = mraa_aio_read_float(dev->aio);
     if (*value < 0)
         return UPM_ERROR_OPERATION_FAILED;
+    return UPM_SUCCESS;
 }
 
 upm_result_t flex_get_raw_volts(const flex_context dev, float *value)
diff --git a/src/gas/mqx.c b/src/gas/mqx.c
index 9a4ef77d..28548a2c 100644
--- a/src/gas/mqx.c
+++ b/src/gas/mqx.c
@@ -94,6 +94,7 @@ upm_result_t mqx_get_normalized(const mqx_context dev, float *value)
     *value = mraa_aio_read_float(dev->aio);
     if (*value < 0)
         return UPM_ERROR_OPERATION_FAILED;
+    return UPM_SUCCESS;
 }
 
 upm_result_t mqx_get_raw_volts(const mqx_context dev, float *value)
diff --git a/src/grove/grove.hpp b/src/grove/grove.hpp
index 82fab7ef..6bdaf3de 100644
--- a/src/grove/grove.hpp
+++ b/src/grove/grove.hpp
@@ -27,6 +27,4 @@
 
 #include <grovebutton.hpp>
 #include <groveled.hpp>
-#include <relay.hpp>
-#include <rotary.hpp>
 #include <grovetemp.hpp>
diff --git a/src/grove/javaupm_grove.i b/src/grove/javaupm_grove.i
index 735f4503..1af48fcc 100644
--- a/src/grove/javaupm_grove.i
+++ b/src/grove/javaupm_grove.i
@@ -24,16 +24,6 @@
     #include "groveled.hpp"
 %}
 
-%include "relay.hpp"
-%{
-    #include "relay.hpp"
-%}
-
-%include "rotary.hpp"
-%{
-    #include "rotary.hpp"
-%}
-
 %include "grovetemp.hpp"
 %{
     #include "grovetemp.hpp"
diff --git a/src/grove/jsupm_grove.i b/src/grove/jsupm_grove.i
index ad54df78..367c9a8d 100644
--- a/src/grove/jsupm_grove.i
+++ b/src/grove/jsupm_grove.i
@@ -21,16 +21,6 @@
     #include "groveled.hpp"
 %}
 
-%include "relay.hpp"
-%{
-    #include "relay.hpp"
-%}
-
-%include "rotary.hpp"
-%{
-    #include "rotary.hpp"
-%}
-
 %include "grovetemp.hpp"
 %{
     #include "grovetemp.hpp"
diff --git a/src/grove/pyupm_grove.i b/src/grove/pyupm_grove.i
index b8751f1a..234085bf 100644
--- a/src/grove/pyupm_grove.i
+++ b/src/grove/pyupm_grove.i
@@ -25,16 +25,6 @@
     #include "groveled.hpp"
 %}
 
-%include "relay.hpp"
-%{
-    #include "relay.hpp"
-%}
-
-%include "rotary.hpp"
-%{
-    #include "rotary.hpp"
-%}
-
 %include "grovetemp.hpp"
 %{
     #include "grovetemp.hpp"
diff --git a/src/gsr/gsr.c b/src/gsr/gsr.c
index 6cc90eb9..eb91c5a1 100644
--- a/src/gsr/gsr.c
+++ b/src/gsr/gsr.c
@@ -94,6 +94,7 @@ upm_result_t gsr_get_normalized(const gsr_context dev, float *value)
     *value = mraa_aio_read_float(dev->aio);
     if (*value < 0)
         return UPM_ERROR_OPERATION_FAILED;
+    return UPM_SUCCESS;
 }
 
 upm_result_t gsr_get_raw_volts(const gsr_context dev, float *value)
diff --git a/src/ldt0028/ldt0028.c b/src/ldt0028/ldt0028.c
index 9b46746b..e9e3112c 100644
--- a/src/ldt0028/ldt0028.c
+++ b/src/ldt0028/ldt0028.c
@@ -94,6 +94,7 @@ upm_result_t ldt0028_get_normalized(const ldt0028_context dev, float *value)
     *value = mraa_aio_read_float(dev->aio);
     if (*value < 0)
         return UPM_ERROR_OPERATION_FAILED;
+    return UPM_SUCCESS;
 }
 
 upm_result_t ldt0028_get_raw_volts(const ldt0028_context dev, float *value)
diff --git a/src/light/light.c b/src/light/light.c
index 359f6c6e..43887fd3 100644
--- a/src/light/light.c
+++ b/src/light/light.c
@@ -95,6 +95,7 @@ upm_result_t light_get_normalized(const light_context dev, float *value)
     *value = mraa_aio_read_float(dev->aio);
     if (*value < 0)
         return UPM_ERROR_OPERATION_FAILED;
+    return UPM_SUCCESS;
 }
 
 upm_result_t light_get_raw_volts(const light_context dev, float *value)
diff --git a/src/slide/slide.c b/src/slide/slide.c
index a45055aa..9b6a7f4f 100644
--- a/src/slide/slide.c
+++ b/src/slide/slide.c
@@ -94,6 +94,7 @@ upm_result_t slide_get_normalized(const slide_context dev, float *value)
     *value = mraa_aio_read_float(dev->aio);
     if (*value < 0)
         return UPM_ERROR_OPERATION_FAILED;
+    return UPM_SUCCESS;
 }
 
 upm_result_t slide_get_raw_volts(const slide_context dev, float *value)