diff --git a/src/sfeTk/sfeTkError.h b/src/sfeTk/sfeTkError.h
index cf78ade..fa457ae 100644
--- a/src/sfeTk/sfeTkError.h
+++ b/src/sfeTk/sfeTkError.h
@@ -27,7 +27,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #pragma once
 
 
-#include <cstdint>
+#include <stdint.h>
 
 //
 // General Concept
diff --git a/src/sfeTkArdI2C.cpp b/src/sfeTkArdI2C.cpp
index 3374419..86daf57 100644
--- a/src/sfeTkArdI2C.cpp
+++ b/src/sfeTkArdI2C.cpp
@@ -116,7 +116,7 @@ sfeTkError_t sfeTkArdI2C::writeRegisterWord(uint8_t devReg, uint16_t dataToWrite
     if (!_i2cPort)
         return kSTkErrBusNullPtr;
 
-    return writeRegisterRegion(devReg, (uint8_t *)&dataToWrite, sizeof(u_int16_t));
+    return writeRegisterRegion(devReg, (uint8_t *)&dataToWrite, sizeof(uint16_t));
 }
 
 //---------------------------------------------------------------------------------
@@ -126,7 +126,7 @@ sfeTkError_t sfeTkArdI2C::writeRegisterWord(uint8_t devReg, uint16_t dataToWrite
 //
 // Returns the number of bytes written, < 0 is an error
 //
-sfeTkError_t sfeTkArdI2C::writeRegisterRegion(uint8_t devReg, const uint8_t *data, size_t length)
+int32_t sfeTkArdI2C::writeRegisterRegion(uint8_t devReg, const uint8_t *data, size_t length)
 {
     if (!_i2cPort)
         return kSTkErrBusNullPtr;
@@ -135,7 +135,7 @@ sfeTkError_t sfeTkArdI2C::writeRegisterRegion(uint8_t devReg, const uint8_t *dat
     _i2cPort->write(devReg);
     _i2cPort->write(data, (int)length);
 
-    return _i2cPort->endTransmission() ? kSTkErrFail : kSTkErrOk; 
+    return _i2cPort->endTransmission() ? length : kSTkErrOk; 
 }
 
 //---------------------------------------------------------------------------------
@@ -204,7 +204,7 @@ int32_t sfeTkArdI2C::readRegisterRegion(uint8_t devReg, uint8_t *data, size_t nu
     uint16_t nOrig = numBytes; // original number of bytes.
     uint8_t nChunk;
     uint16_t nReturned;
-    int i;                   // counter in loop
+    uint16_t i;                   // counter in loop
     bool bFirstInter = true; // Flag for first iteration - used to send devRegister
 
     while (numBytes > 0)
diff --git a/src/sfeTkArdI2C.h b/src/sfeTkArdI2C.h
index 6e729dd..94661f5 100644
--- a/src/sfeTkArdI2C.h
+++ b/src/sfeTkArdI2C.h
@@ -124,7 +124,7 @@ class sfeTkArdI2C : public sfeTkII2C
 
         @retval returns number of bytes written, < 0 is an error code
     */
-    virtual int writeRegisterRegion(uint8_t devReg, const uint8_t *data, size_t length);
+    virtual int32_t writeRegisterRegion(uint8_t devReg, const uint8_t *data, size_t length);
 
     /*--------------------------------------------------------------------------
         @brief Reads a byte of data from the given register.
diff --git a/src/sfeTkArdSPI.cpp b/src/sfeTkArdSPI.cpp
index 6bf8b28..2dafdc3 100644
--- a/src/sfeTkArdSPI.cpp
+++ b/src/sfeTkArdSPI.cpp
@@ -65,7 +65,7 @@ sfeTkError_t sfeTkArdSPI::init(SPIClass &spiPort, SPISettings &busSPISettings, u
 sfeTkError_t sfeTkArdSPI::init(uint8_t csPin, bool bInit)
 {
     // If the transaction settings are not provided by the user they are built here.
-    SPISettings spiSettings = SPISettings(3000000, SPI_MSBFIRST, SPI_MODE3);
+    SPISettings spiSettings = SPISettings(3000000, MSBFIRST, SPI_MODE3);
 
     // In addition of the port is not provided by the user, it defaults to SPI here.
     return init(SPI, spiSettings, csPin, bInit);
@@ -126,7 +126,7 @@ sfeTkError_t sfeTkArdSPI::writeRegisterWord(uint8_t devReg, uint16_t dataToWrite
 //
 // Returns the number of bytes written, < 0 is an error
 //
-int sfeTkArdSPI::writeRegisterRegion(uint8_t devReg, const uint8_t *data, size_t length)
+int32_t sfeTkArdSPI::writeRegisterRegion(uint8_t devReg, const uint8_t *data, size_t length)
 {
     if (!_spiPort)
         return kSTkErrBusNullPtr;
@@ -178,7 +178,7 @@ sfeTkError_t sfeTkArdSPI::readRegisterRegion(uint8_t devReg, uint8_t *data, size
     // A leading "1" must be added to transfer with devRegister to indicate a "read"
     _spiPort->transfer(devReg | kSPIReadBit);
 
-    for (int i = 0; i < numBytes; i++)
+    for (size_t i = 0; i < numBytes; i++)
         *data++ = _spiPort->transfer(0x00);
 
     // End transaction