RobTillaart · RobTillaart · Jun 5, 2026 · Jun 5, 2026
diff --git a/.github/workflows/arduino-lint.yml b/.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

diff --git a/.github/workflows/arduino_test_runner.yml b/.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

diff --git a/.github/workflows/jsoncheck.yml b/.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:

diff --git a/CHANGELOG.md b/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/).
 
 
+## [0.1.6] - 2026-06-05
+- add setInvert(bool) and getInvert()
+- update GitHub actions
+- minor edits
+
 ## [0.1.5] - 2025-09-12
 - update GitHub actions
 - minor edits

diff --git a/LICENSE b/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

diff --git a/README.md b/README.md
@@ -18,10 +18,16 @@ Arduino library for shiftIn with build-in delay - e.g. for 74HC165.
 
 **Experimental**
 
-shiftInSlow 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.
+shiftInSlow is a library which has a build in delay (in microseconds) 
+that allows tuning the time per bit. 
+This can help to improve reliability e.g. when using long lines.
 
-The dataPin and clockPin are set in the constructor, the delay is configurable per byte send to be able to optimize runtime.
+The dataPin and clockPin and bitOrder are set in the constructor.
+The (bit) delay is configurable before every byte send to be able 
+to optimize runtime. 
+Default there is no delay.
+
+Feedback as always is welcome.
 
 
 ### Related
@@ -35,14 +41,14 @@ The dataPin and clockPin are set in the constructor, the delay is configurable p
 
 ## Performance
 
-The performance of **read()** with a delay of 0 microseconds is slower than the default Arduino 
-**shiftIn()** due to some overhead. 
+The performance of **read()** with a delay of 0 microseconds is slower
+ than the default Arduino **shiftIn()** due to some overhead. 
 
-The delay requested is split in two (expect rounding errors) to have "nice" looking pulse
-with the duty cycle around 50%.
+The delay requested is split in two (expect rounding errors) to have 
+"nice" looking pulse with the duty cycle around 50%.
 
-Performance measurements are meaningless, as the purpose of this library is to 
-slow the pulse train to a working level.
+Performance measurements are meaningless, as the purpose of this library
+is to slow down the pulse train to a working level.
 
 
 ## Interface
@@ -55,18 +61,37 @@ slow the pulse train to a working level.
 
 - **ShiftInSlow(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder = LSBFIRST)** constructor, 
 bit order is default set to LSBFIRST.
+Default there is no delay (0 us).
 
-### Functions
+### Read
 
 - **int read()** reads a new value.
-- **int lastRead()** returns last value read.
-- **void setDelay(uint16_t microseconds = 0)** set delay per bit from 0 .. 65535 microseconds. 
+- **int lastRead()** returns last value read from cache.
+
+### Delay
+
+- **void setDelay(uint16_t microseconds = 0)** set delay per bit 
+from 0 .. 65535 microseconds. 
 Note that the delay is split in two parts to keep the duty cycle around 50%.
 Note that odd delays will get a truncating error.
 - **uint16_t getDelay()** returns the set delay in microseconds.
-- **bool setBitOrder(uint8_t bitOrder = LSBFIRST)** set LSBFIRST or MSBFIRST. Returns false for other values.
+
+### BitOrder
+
+- **bool setBitOrder(uint8_t bitOrder = LSBFIRST)** set LSBFIRST or MSBFIRST. 
+Returns false for other values (so bitOrder is not changed).
 - **uint8_t getBitOrder(void)** returns LSBFIRST or MSBFIRST.
 
+### Invert
+
+(new in 0.1.6)
+
+- **void setInvert(bool invert = false)** invert the data read.
+- **uint16_t getInvert()**
+
+If the byte read is inverted, the **lastRead()** will return 
+the inverted value too.
+
 
 ## Operation
 
@@ -83,16 +108,16 @@ See examples.
 
 - Add a select pin to be more SPI alike?
   - would allow SPI debugging?
-- increase max delay uint32_t ?
-  - would allow pulses in "second" domain.
-  - millis() clock iso micros()
 - fix odd delays rounding error
   - get uneven duty cycle is result.
 
 #### Could
 
 - add examples
   - adaptive speed example?
+- reverse flag to change "BitOrder in software"?
+  - parameter for read(bool reverse) or lastRead(reverse)
+  - faster than rereading (if possible)
 
 #### Wont
 
@@ -103,7 +128,10 @@ See examples.
 - set delay in terms of frequency - delay is 'wave length'
 - set delay in terms of max total time the read may cost.
 - read16/24/32 to read more bytes is a user task.
-
+- increase max delay uint32_t ?
+  - would allow pulses in "second" domain.
+  - and blocking for long time.
+  - millis() clock instead of micros()
 
 ## Support
 

diff --git a/ShiftInSlow.cpp b/ShiftInSlow.cpp
@@ -1,9 +1,9 @@
 //
 //    FILE: ShiftInSlow.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.5
-// PURPOSE: Arduino library for shiftIn with build-in delay
+// VERSION: 0.1.6
 //    DATE: 2021-05-11
+// PURPOSE: Arduino library for shiftIn with build-in delay
 //     URL: https://github.com/RobTillaart/ShiftInSlow
 
 
@@ -39,6 +39,10 @@ int ShiftInSlow::read()
     digitalWrite(_clockPin, LOW);
     if (_delay > 0) delayMicroseconds(_delay / 2);
   }
+  if (_invert)
+  {
+    _value ^= 0xFF;
+  }
   return _value;
 }
 
@@ -77,5 +81,17 @@ uint16_t ShiftInSlow::getDelay()
 }
 
 
+void ShiftInSlow::setInvert(bool invert)
+{
+  _invert = invert;
+}
+
+
+uint16_t ShiftInSlow::getInvert()
+{
+  return _invert;
+}
+
+
 //  -- END OF FILE --
 
diff --git a/ShiftInSlow.h b/ShiftInSlow.h
@@ -2,16 +2,16 @@
 //
 //    FILE: ShiftInSlow.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.5
-// PURPOSE: Arduino library for shiftIn with build-in delay
+// VERSION: 0.1.6
 //    DATE: 2021-05-11
+// PURPOSE: Arduino library for shiftIn with build-in delay
 //     URL: https://github.com/RobTillaart/ShiftInSlow
 
 
 #include "Arduino.h"
 
 
-#define SHIFTINSLOW_LIB_VERSION           (F("0.1.5"))
+#define SHIFTINSLOW_LIB_VERSION           (F("0.1.6"))
 
 
 class ShiftInSlow
@@ -29,13 +29,17 @@ class ShiftInSlow
   void     setDelay(uint16_t microseconds = 0);
   uint16_t getDelay();
 
+  void     setInvert(bool invert = false);
+  uint16_t 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;
 };
 
 

diff --git a/examples/shiftInSlow_demo/output_0.1.6.txt b/examples/shiftInSlow_demo/output_0.1.6.txt
@@ -0,0 +1,109 @@
+IDE:    1.8.19
+BOARD:  UNO R3
+
+shiftInSlow_demo.ino
+SHIFTINSLOW_LIB_VERSION: 0.1.6
+
+0	204	25.5
+10	264	33.0
+20	348	43.5
+30	424	53.0
+40	504	63.0
+50	584	73.0
+60	668	83.5
+70	748	93.5
+80	828	103.5
+90	908	113.5
+100	992	124.0
+110	1068	133.5
+120	1152	144.0
+130	1236	154.5
+140	1312	164.0
+150	1392	174.0
+160	1468	183.5
+170	1556	194.5
+180	1636	204.5
+190	1716	214.5
+200	1788	223.5
+210	1876	234.5
+220	1956	244.5
+230	2036	254.5
+240	2116	264.5
+250	2200	275.0
+260	2276	284.5
+270	2356	294.5
+280	2444	305.5
+290	2524	315.5
+300	2600	325.0
+310	2680	335.0
+320	2764	345.5
+330	2844	355.5
+340	2920	365.0
+350	3000	375.0
+360	3080	385.0
+370	3160	395.0
+380	3248	406.0
+390	3324	415.5
+400	3404	425.5
+410	3488	436.0
+420	3568	446.0
+430	3648	456.0
+440	3728	466.0
+450	3808	476.0
+460	3884	485.5
+470	3968	496.0
+480	4048	506.0
+490	4128	516.0
+500	4208	526.0
+510	4288	536.0
+520	4376	547.0
+530	4448	556.0
+540	4528	566.0
+550	4612	576.5
+560	4688	586.0
+570	4772	596.5
+580	4856	607.0
+590	4932	616.5
+600	5016	627.0
+610	5092	636.5
+620	5176	647.0
+630	5256	657.0
+640	5332	666.5
+650	5416	677.0
+660	5496	687.0
+670	5580	697.5
+680	5660	707.5
+690	5740	717.5
+700	5820	727.5
+710	5896	737.0
+720	5980	747.5
+730	6060	757.5
+740	6140	767.5
+750	6220	777.5
+760	6308	788.5
+770	6380	797.5
+780	6464	808.0
+790	6548	818.5
+800	6628	828.5
+810	6708	838.5
+820	6784	848.0
+830	6868	858.5
+840	6940	867.5
+850	7024	878.0
+860	7108	888.5
+870	7184	898.0
+880	7264	908.0
+890	7344	918.0
+900	7428	928.5
+910	7504	938.0
+920	7588	948.5
+930	7668	958.5
+940	7752	969.0
+950	7828	978.5
+960	7908	988.5
+970	7996	999.5
+980	8072	1009.0
+990	8152	1019.0
+1000	8232	1029.0
+
+done...
diff --git a/examples/shiftInSlow_demo/shiftInSlow_demo.ino b/examples/shiftInSlow_demo/shiftInSlow_demo.ino
@@ -37,7 +37,7 @@ void setup()
     Serial.print("\n");
   }
 
-  Serial.println("done...");
+  Serial.println("\ndone...");
 }
 
 
@@ -46,4 +46,4 @@ void loop()
 }
 
 
-// -- END OF FILE --
+//  -- END OF FILE --
diff --git a/keywords.txt b/keywords.txt
@@ -15,6 +15,9 @@ getBitOrder	KEYWORD2
 setDelay	KEYWORD2
 getDelay	KEYWORD2
 
+setInvert	KEYWORD2
+getInvert	KEYWORD2
+
 
 # Constants (LITERAL1)
 SHIFTINSLOW_LIB_VERSION	LITERAL1

diff --git a/library.json b/library.json
@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/ShiftInSlow.git"
   },
-  "version": "0.1.5",
+  "version": "0.1.6",
   "license": "MIT",
   "frameworks": "*",
   "platforms": "*",

diff --git a/library.properties b/library.properties
@@ -1,5 +1,5 @@
 name=ShiftInSlow
-version=0.1.5
+version=0.1.6
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino library for shiftIn with build-in delay - e.g. for 74HC165