fix #47, enable interrupts. (#49)

- fix #47, interrupt handling. Kudos to GlibSkunk!
- update readme.md
- minor edits.

CHANGELOG.md

@@ -6,6 +6,13 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
+## [0.6.0] - 2024-11-19
+- fix #47, interrupt handling. Kudos to GlibSkunk!
+- update readme.md
+- minor edits.
+
+----
+
 ## [0.5.4] - 2024-07-04
 - fix #45, documentation bug
 

MCP23S17.cpp

@@ -1,7 +1,7 @@
 //
 //    FILE: MCP23S17.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.5.4
+// VERSION: 0.6.0
 // PURPOSE: Arduino library for SPI MCP23S17 16 channel port expander
 //    DATE: 2021-12-30
 //     URL: https://github.com/RobTillaart/MCP23S17
@@ -570,114 +570,108 @@ bool MCP23S17::enableInterrupt(uint8_t pin, uint8_t mode)
     _error = MCP23S17_PIN_ERROR;
     return false;
   }
-	
+
   uint8_t INTCONREG = MCP23x17_INTCON_A;
-	uint8_t DEFVALREG = MCP23x17_DEFVAL_A;
-	uint8_t GPINTENREG = MCP23x17_GPINTEN_A;
+  uint8_t DEFVALREG = MCP23x17_DEFVAL_A;
+  uint8_t GPINTENREG = MCP23x17_GPINTEN_A;
   if (pin > 7)
   {
     INTCONREG = MCP23x17_INTCON_B;
-		DEFVALREG = MCP23x17_DEFVAL_B;
-		GPINTENREG = MCP23x17_GPINTEN_B;
+    DEFVALREG = MCP23x17_DEFVAL_B;
+    GPINTENREG = MCP23x17_GPINTEN_B;
     pin -= 8;
   }
-	uint8_t mask = 1 << pin;
+  uint8_t mask = 1 << pin;
 
   uint8_t intcon = readReg(INTCONREG);
-	uint8_t pre_intcon = intcon;
+  uint8_t pre_intcon = intcon;
   if (_error != MCP23S17_OK)
   {
     return false;
   }
-	
-	if (mode == CHANGE)
-	{
-		// Compare to previous value
-		intcon &= ~mask;
-	}
-	else
-	{	
-		// Compare to DEFVALREG
-		intcon |= mask;
-		
-		// Get and Modify Pin's Value in DEFVALREG
-		uint8_t defval = readReg(DEFVALREG);
-		uint8_t pre_defval = defval;
+
+  if (mode == CHANGE)
+  {
+    //  Compare to previous value
+    intcon &= ~mask;
+  }
+  else
+  {
+    //  Compare to DEFVALREG
+    intcon |= mask;
+
+    //  Get and Modify Pin's Value in DEFVALREG
+    uint8_t defval = readReg(DEFVALREG);
+    uint8_t pre_defval = defval;
     if (mode == RISING)
     {
-			defval &= ~mask; 	//  RISING == compare to 0 
+      defval &= ~mask;   //  RISING == compare to 0
     }
     else if (mode == FALLING)
     {
-			defval |= mask;		//  FALLING == compare to 1
-		}
-		//  only write when changed.
-		if (pre_defval != defval)
-		{
-			writeReg(DEFVALREG, defval);
-			if (_error != MCP23S17_OK)
-			{
-				return false;
-			}
-		}
-	}
-	//  only write when changed.
-	if (pre_intcon != intcon)
-	{
-		writeReg(INTCONREG, intcon);
-		if (_error != MCP23S17_OK)
-		{
-			return false;
-		}
-	}
-	
+      defval |= mask;    //  FALLING == compare to 1
+    }
+    //  only write when changed.
+    if (pre_defval != defval)
+    {
+      writeReg(DEFVALREG, defval);
+      if (_error != MCP23S17_OK)
+      {
+        return false;
+      }
+    }
+  }
+  //  only write when changed.
+  if (pre_intcon != intcon)
+  {
+    writeReg(INTCONREG, intcon);
+    if (_error != MCP23S17_OK)
+    {
+      return false;
+    }
+  }
+
   //  enable interrupt
-	uint8_t gpinten = readReg(GPINTENREG);
-	uint8_t pre_gpinten = gpinten;
-	gpinten |= mask;
-	if (pre_gpinten != gpinten)
-	{
-		return writeReg(GPINTENREG, gpinten);
-	}
-	else
-	{
-		return true;	// Already enabled for pin
-	}
+  uint8_t gpinten = readReg(GPINTENREG);
+  uint8_t pre_gpinten = gpinten;
+  gpinten |= mask;
+  if (pre_gpinten != gpinten)
+  {
+    return writeReg(GPINTENREG, gpinten);
+  }
+  return true;  //  Already enabled for pin
 }
 
+
 bool MCP23S17::disableInterrupt(uint8_t pin)
 {
   if (pin > 15)
   {
     _error = MCP23S17_PIN_ERROR;
     return false;
   }
-	
-	uint8_t GPINTENREG = MCP23x17_GPINTEN_A;
+
+  uint8_t GPINTENREG = MCP23x17_GPINTEN_A;
   if (pin > 7)
   {
-		GPINTENREG = MCP23x17_GPINTEN_B;
+    GPINTENREG = MCP23x17_GPINTEN_B;
     pin -= 8;
   }
-	uint8_t mask = 1 << pin;
-
+  uint8_t mask = 1 << pin;
 
-	//  disable interrupt
-	uint8_t gpinten = readReg(GPINTENREG);
-	uint8_t pre_gpinten = gpinten;
-	if (_error != MCP23S17_OK)
+  //  disable interrupt
+  uint8_t gpinten = readReg(GPINTENREG);
+  uint8_t pre_gpinten = gpinten;
+  if (_error != MCP23S17_OK)
   {
     return false;
   }
-	gpinten &= ~mask;
-	if (pre_gpinten != gpinten)
-	{
-		return writeReg(GPINTENREG, gpinten);
-	}
-	else
-	{
-		return true;	// Already disabled for pin
-	}
+  gpinten &= ~mask;
+  if (pre_gpinten != gpinten)
+  {
+    return writeReg(GPINTENREG, gpinten);
+  }
+  return true;  //  Already disabled for pin
 }
 
 
@@ -692,15 +686,14 @@ bool MCP23S17::enableInterrupt16(uint16_t mask, uint8_t mode)
   }
   else
   {
+    intcon = mask;
     if (mode == RISING)
     {
-      intcon = mask;
       defval = ~mask;  //  RISING == compare to 0
     }
     else if (mode == FALLING)
     {
-      intcon = mask;
-      defval = mask;  //  FALLING == compare to 1
+      defval = mask;   //  FALLING == compare to 1
     }
     writeReg16(MCP23x17_DEFVAL_A, defval);
   }

MCP23S17.h

@@ -2,7 +2,7 @@
 //
 //    FILE: MCP23S17.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.5.4
+// VERSION: 0.6.0
 // 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("0.5.4"))
+#define MCP23S17_LIB_VERSION              (F("0.6.0"))
 
 //  ERROR CODES
 #define MCP23S17_OK                       0x00
@@ -70,7 +70,7 @@ class MCP23S17
 
   //       8 pins interface
   //       port  = 0..1
-  //       mask  = 0x00..0xFF  bit pattern, 
+  //       mask  = 0x00..0xFF  bit pattern,
   //               bit 0 = output mode, bit 1 = input mode
   //       value = bit pattern.
   bool     pinMode8(uint8_t port, uint8_t mask);
@@ -101,7 +101,7 @@ class MCP23S17
   //       pin = 0..15, mode = { RISING, FALLING, CHANGE }
   bool     enableInterrupt(uint8_t pin, uint8_t mode);
   bool     disableInterrupt(uint8_t pin);
-  
+
   //       mask = 0x0000..0xFFFF  (overrides all earlier settings.
   bool     enableInterrupt16(uint16_t mask, uint8_t mode);
   bool     disableInterrupt16(uint16_t mask);

README.md

@@ -24,15 +24,18 @@ 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.
 
+### 0.6.0 Breaking change
 
-#### 0.5.0 Breaking change
+Fix for #47, bug in enable interrupt handling.
+Pre 0.6.0 versions are obsolete.
+
+### 0.5.0 Breaking change
 
 Version 0.5.0 introduced a breaking change to improve handling the SPI dependency.
 The user has to call **SPI.begin()** or equivalent before calling **MCP.begin()**.
 Optionally the user can provide parameters to the **SPI.begin(...)**
 
-
-#### 0.4.0 Breaking change
+### 0.4.0 Breaking change
 
 The version 0.4.0 has breaking changes in the interface. 
 The rationale is that the programming environment of the **Arduino ESP32 S3** 
@@ -54,15 +57,15 @@ The following library functions have been renamed:
 |  digitalWrite()  |  write1()    |
 
 
-#### 0.3.0 Breaking change
+### 0.3.0 Breaking change
 
 The version 0.3.0 has breaking changes in the interface. 
 The essence is removal of ESP32 specific code from the library. 
 This makes it possible to support the ESP32-S3 and other processors in the future. 
 Also it makes the library a bit simpler to maintain.
 
 
-#### Related
+### Related
 
 16 bit port expanders
 
@@ -111,7 +114,7 @@ The two hardware constructors allow to call 4 different constructors.
 ```
 
 
-#### Sharing SELECT lines
+### Sharing SELECT lines
 
 (verified in #19)  
 Technically two chips could use the same SELECT pin and a different address. 
@@ -184,7 +187,6 @@ If there are problems please open an issue.
 ### Interrupts (experimental 0.5.2)
 
 Read the datasheet for the details, page 24,25.  
-Note: Error handling is limited.
 
 pin = 0..15  
 mode = { RISING, FALLING, CHANGE }  

library.json

@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/MCP23S17.git"
   },
-  "version": "0.5.4",
+  "version": "0.6.0",
   "license": "MIT",
   "frameworks": "*",
   "platforms": "*",

library.properties

@@ -1,5 +1,5 @@
 name=MCP23S17
-version=0.5.4
+version=0.6.0
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino library for SPI MCP23S17 16 channel port expander 16 IO-lines