diff --git a/README.md b/README.md
index 137dd6b..23c2cdc 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,3 @@
-# SparkFun Toolkit Arduino Library
\ No newline at end of file
+# SparkFun Toolkit Arduino Library
+
+![Toolkit Tests Builds](https://github.com/sparkfun/SparkFun_Toolkit/actions/workflows/compile-sketch.yml/badge.svg)
diff --git a/src/sfeTkArdI2C.h b/src/sfeTkArdI2C.h
index 94661f5..f926b54 100644
--- a/src/sfeTkArdI2C.h
+++ b/src/sfeTkArdI2C.h
@@ -27,6 +27,7 @@ over Inter-Integrated Circuit (I2C) in Arduino
 
 #pragma once
 
+#include <Arduino.h>
 #include <Wire.h>
 
 // Include our platform I2C interface definition.
diff --git a/src/sfeTkArdSPI.cpp b/src/sfeTkArdSPI.cpp
index 2dafdc3..838185c 100644
--- a/src/sfeTkArdSPI.cpp
+++ b/src/sfeTkArdSPI.cpp
@@ -131,14 +131,14 @@ int32_t sfeTkArdSPI::writeRegisterRegion(uint8_t devReg, const uint8_t *data, si
     if (!_spiPort)
         return kSTkErrBusNullPtr;
 
-    // Apply settings
+    // Apply settings before work
     _spiPort->beginTransaction(_sfeSPISettings);
 
     // Signal communication start
     digitalWrite(cs(), LOW);
     _spiPort->transfer(devReg);
 
-    for (int i = 0; i < length; i++)
+    for (size_t i = 0; i < length; i++)
         _spiPort->transfer(*data++);
 
     // End communication