add setInvert() + getInvert()

.github/workflows/arduino-lint.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: arduino/arduino-lint-action@v2
         with:
           library-manager: update

.github/workflows/arduino_test_runner.yml

@@ -6,9 +6,8 @@ jobs:
   runTest:
     runs-on: ubuntu-latest
     timeout-minutes: 20
-
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: 2.6

.github/workflows/jsoncheck.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: json-syntax-check
         uses: limitusus/json-syntax-check@v2
         with:

CHANGELOG.md

@@ -6,6 +6,11 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
+## [0.1.7] - 2026-06-05
+- add setInvert(bool) and getInvert()
+- update GitHub actions
+- minor edits
+
 ## [0.1.6] - 2025-09-12
 - update GitHub actions
 - minor edits

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2021-2025 Rob Tillaart
+Copyright (c) 2021-2026 Rob Tillaart
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -18,13 +18,17 @@ Arduino library for shiftOut with build-in delay - e.g. for 74HC595
 
 **Experimental**
 
-ShiftOutSlow is an experimental library that has a build in delay (in microseconds) that allows tuning the time per bit.
+ShiftOutSlow is an experimental library that has a build in delay 
+(in microseconds) that allows tuning the time per bit.
 This allows one to improve reliability e.g. when using longer lines.
 
-The data pin and clock pin are set in the constructor, the delay can be set per byte send to be able to optimize runtime.
+The data pin and clock pin are set in the constructor, the delay 
+can be set per byte send to be able to optimize runtime.
 
 ShiftOutSlow implements the print interface.
 
+Feedback as always is welcome.
+
 
 #### Related
 
@@ -37,11 +41,11 @@ ShiftOutSlow implements the print interface.
 
 ## Performance
 
-The performance of **write()** with a delay of 0 microseconds is slower than the default Arduino
-**shiftOut()** due to some overhead.
+The performance of **write()** with a delay of 0 microseconds is slower
+than the default Arduino **shiftOut()** due to some overhead.
 
-The delay requested is divided by two to minimize disruption of the duty cycle of the clock pulse,
-resulting in "better" pulses.
+The delay requested is divided by two to minimize disruption of the 
+duty cycle of the clock pulse, resulting in "better" pulses.
 
 Performance measurements are meaningless, as the purpose of this library is to 
 slow the pulse train to a working level.
@@ -57,7 +61,7 @@ slow the pulse train to a working level.
 
 - **ShiftOutSlow(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder = LSBFIRST)** constructor.
 
-### Functions
+### Write
 
 The interface exists of the following functions:
 
@@ -67,15 +71,31 @@ Returns the bytes written.
 Uses **write(uint8_t)** so expect about equal performance.
 Returns the bytes written.
 - **uint8_t lastWritten()** returns last value written.
+
+### Delay
+
 - **void setDelay(uint16_t microSeconds = 0)** set delay per **bit** from 0 .. 65535 microseconds. 
 Note: the delay is not the time per bit but an additional time per bit.
 Note: the delay can be set runtime per write / print call.
 - **uint16_t getDelay()** returns the set delay in microseconds.
+
+### BitOrder
+
 - **bool setBitOrder(uint8_t bitOrder = LSBFIRST)** set LSBFIRST or MSBFIRST.
 Returns false for other values.
 Note: bit order can be changed runtime per write / print call.
 - **uint8_t getBitOrder()** returns LSBFIRST or MSBFIRST (typical 0 and 1).
 
+### Invert
+
+(new in 0.1.7)
+
+- **void setInvert(bool invert = false)** invert the data written.
+- **uint16_t getInvert()** idem.
+
+If the byte written is inverted, the **lastWritten()** will return 
+the inverted value too.
+
 
 ### Print interface
 

ShiftOutSlow.cpp

@@ -1,9 +1,9 @@
 //
 //    FILE: ShiftOutSlow.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.6
-// PURPOSE: Arduino library for shiftOut with build-in delay
+// VERSION: 0.1.7
 //    DATE: 2021-05-11
+// PURPOSE: Arduino library for shiftOut with build-in delay
 //     URL: https://github.com/RobTillaart/ShiftOutSlow
 
 
@@ -28,6 +28,11 @@ size_t ShiftOutSlow::write(const uint8_t data)
   uint8_t   val = data;
   uint16_t  d1  = _delay/2;
   uint16_t  d2  = _delay - d1;
+  if (_invert)
+  {
+    val ^= 0xFF;
+  }
+  _value = val;
   for (uint8_t i = 0; i < 8; ++i)
   {
     if (d1) delayMicroseconds(d1);
@@ -43,7 +48,6 @@ size_t ShiftOutSlow::write(const uint8_t data)
     yield();
     digitalWrite(_clockPin, LOW);
   }
-  _value = data;
   return 1;
 }
 
@@ -93,5 +97,17 @@ uint16_t ShiftOutSlow::getDelay()
 }
 
 
+void ShiftOutSlow::setInvert(bool invert)
+{
+  _invert = invert;
+}
+
+
+bool ShiftOutSlow::getInvert()
+{
+  return _invert;
+}
+
+
 //  -- END OF FILE --
 

ShiftOutSlow.h

@@ -2,16 +2,16 @@
 //
 //    FILE: ShiftOutSlow.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.
-// PURPOSE: Arduino library for shiftOut with build-in delay
+// VERSION: 0.1.7
 //    DATE: 2021-05-11
+// PURPOSE: Arduino library for shiftOut with build-in delay
 //     URL: https://github.com/RobTillaart/ShiftOutSlow
 
 
 #include "Arduino.h"
 
 
-#define SHIFTOUTSLOW_LIB_VERSION            (F("0.1.6"))
+#define SHIFTOUTSLOW_LIB_VERSION            (F("0.1.7"))
 
 
 class ShiftOutSlow : public Print
@@ -33,13 +33,17 @@ class ShiftOutSlow : public Print
   void     setDelay(uint16_t microSeconds = 0);
   uint16_t getDelay();
 
+  void     setInvert(bool invert = false);
+  bool     getInvert();
+
 
 private:
   uint8_t  _clockPin = 0;
   uint8_t  _dataPin  = 0;
   uint8_t  _bitOrder = LSBFIRST;
   uint16_t _delay    = 0;
   uint8_t  _value    = 0;
+  bool     _invert   = false;
 };
 
 

examples/shiftOutSlow_demo/output_0.1.7.txt

@@ -0,0 +1,19 @@
+IDE:    1.8.19
+BOARD:  UNO R3
+
+shiftOutSlow_demo.ino
+SHIFTOUTSLOW_LIB_VERSION: 0.1.7
+
+176	0	22.0
+944	100	118.0
+1752	200	219.0
+2556	300	319.5
+3360	400	420.0
+4164	500	520.5
+4972	600	621.5
+5776	700	722.0
+6572	800	821.5
+7388	900	923.5
+8188	1000	1023.5
+
+done...

examples/shiftOutSlow_demo/shiftOutSlow_demo.ino

@@ -37,7 +37,7 @@ void setup()
     delay(20);
   }
 
-  Serial.println("done...");
+  Serial.println("\ndone...");
 }
 
 

keywords.txt

@@ -15,6 +15,9 @@ getBitOrder	KEYWORD2
 setDelay	KEYWORD2
 getDelay	KEYWORD2
 
+setInvert	KEYWORD2
+getInvert	KEYWORD2
+
 
 # Constants (LITERAL1)
 SHIFTOUTSLOW_LIB_VERSION	LITERAL1

library.json

@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/ShiftOutSlow.git"
   },
-  "version": "0.1.6",
+  "version": "0.1.7",
   "license": "MIT",
   "frameworks": "*",
   "platforms": "*",

library.properties

@@ -1,5 +1,5 @@
 name=ShiftOutSlow
-version=0.1.6
+version=0.1.7
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino library for shiftOut with build-in delay - e.g. for 74HC165