fix #50, reverse byte order in 16 bit API

Author: RobTillaart

CHANGELOG.md

@@ -6,6 +6,12 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
+## [0.7.0] - 2025-02-18
+- fix #50, breaking change 16 bit API byte order to be intuitive / logic.
+- update readme.md
+
+----
+
 ## [0.6.1] - 2025-01-20
 - Sync MCP23017 PR #41 interrupt functions.
 - add link to keypad library

MCP23S17.cpp

@@ -1,7 +1,7 @@
 //
 //    FILE: MCP23S17.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.6.1
+// VERSION: 0.7.0
 // PURPOSE: Arduino library for SPI MCP23S17 16 channel port expander
 //    DATE: 2021-12-30
 //     URL: https://github.com/RobTillaart/MCP23S17
@@ -954,17 +954,17 @@ bool MCP23S17::writeReg16(uint8_t reg, uint16_t value)
     //  _address already shifted
     _mySPI->transfer(MCP23S17_WRITE_REG | _address );
     _mySPI->transfer(reg);
-    _mySPI->transfer(value >> 8);
     _mySPI->transfer(value & 0xFF);
+    _mySPI->transfer(value >> 8);
     _mySPI->endTransaction();
   }
   else
   {
     //  _address already shifted
     swSPI_transfer(MCP23S17_WRITE_REG | _address );
     swSPI_transfer(reg);
-    swSPI_transfer(value >> 8);
     swSPI_transfer(value & 0xFF);
+    swSPI_transfer(value >> 8);
   }
   ::digitalWrite(_select, HIGH);
   return true;
@@ -991,17 +991,17 @@ uint16_t MCP23S17::readReg16(uint8_t reg)
     //  _address already shifted
     _mySPI->transfer(MCP23S17_READ_REG | _address );
     _mySPI->transfer(reg);
-    rv = _mySPI->transfer(0xFF) << 8;
-    rv += _mySPI->transfer(0xFF);
+    rv = _mySPI->transfer(0xFF);
+    rv += _mySPI->transfer(0xFF) << 8;
     _mySPI->endTransaction();
   }
   else
   {
     //  _address already shifted
     swSPI_transfer(MCP23S17_READ_REG | _address );
     swSPI_transfer(reg);
-    rv = swSPI_transfer(0xFF) << 8;
-    rv += swSPI_transfer(0xFF);
+    rv = swSPI_transfer(0xFF);
+    rv += swSPI_transfer(0xFF) << 8;
   }
   ::digitalWrite(_select, HIGH);
   return rv;

MCP23S17.h

@@ -2,7 +2,7 @@
 //
 //    FILE: MCP23S17.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.6.1
+// VERSION: 0.7.0
 // PURPOSE: Arduino library for SPI MCP23S17 16 channel port expander
 //    DATE: 2021-12-30
 //     URL: https://github.com/RobTillaart/MCP23S17
@@ -13,7 +13,7 @@
 #include "MCP23x17_registers.h"
 
 
-#define MCP23S17_LIB_VERSION              (F("0.6.1"))
+#define MCP23S17_LIB_VERSION              (F("0.7.0"))
 
 //  ERROR CODES
 #define MCP23S17_OK                       0x00

README.md

@@ -24,9 +24,13 @@ Programming Interface is kept the same as much as possible.
 The **write1(pin, value)** is optimized. 
 If a pin is not changed it will not be written again to save time.
 
+### 0.7.0 Breaking change
+
+Fix #50, reverse byte order in 16 bit interface to be intuitive / logic.
+
 ### 0.6.0 Breaking change
 
-Fix for #47, bug in enable interrupt handling.
+Fix #47, bug in enable interrupt handling.
 Pre 0.6.0 versions are obsolete.
 
 ### 0.5.0 Breaking change

library.json

@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/MCP23S17.git"
   },
-  "version": "0.6.1",
+  "version": "0.7.0",
   "license": "MIT",
   "frameworks": "*",
   "platforms": "*",

library.properties

@@ -1,5 +1,5 @@
 name=MCP23S17
-version=0.6.1
+version=0.7.0
 author=Rob Tillaart <[email protected]>
 maintainer=Rob Tillaart <[email protected]>
 sentence=Arduino library for SPI MCP23S17 16 channel port expander 16 IO-lines