update setChannel() (#6)

- change return type of **bool setChannel()** - verify the channel parameter of **bool setChannel()** - add parameter to **bool setChannel(channel, disable = true)** - update readme.md
RobTillaart · May 28, 2024 · edab20e · edab20e
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diff --git a/CHANGELOG.md b/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/).
 
 
+## [0.2.1] - 2024-05-28
+- change return type of **bool setChannel()**
+- verify the channel parameter of **bool setChannel()**
+- add parameter to **bool setChannel(channel, disable = true)**
+- update readme.md
+
 ## [0.2.0] - 2024-04-03
 - fix ghost channels when using for OUTPUT
   - add disable/enable in setChannel()

diff --git a/HC4067.h b/HC4067.h
@@ -3,15 +3,15 @@
 //    FILE: HC4067.h
 //  AUTHOR: Rob Tillaart
 //    DATE: 2023-01-25
-// VERSION: 0.2.0
+// VERSION: 0.2.1
 // PURPOSE: Arduino library for CD74HC4067 1 x 16 channel multiplexer and compatibles.
 //     URL: https://github.com/RobTillaart/HC4067
 
 
 
 #include "Arduino.h"
 
-#define HC4067_LIB_VERSION         (F("0.2.0"))
+#define HC4067_LIB_VERSION         (F("0.2.1"))
 
 
 class HC4067
@@ -40,15 +40,19 @@ class HC4067
   }
 
 
-  void setChannel(uint8_t channel)
+  bool setChannel(uint8_t channel, bool disable = true)
   {
-    uint8_t _new = channel & 0x0F;
+    if (channel > 15) return false;
+    uint8_t _new = channel;
     if (_new != _channel)
     {
       uint8_t _changed = _new ^ _channel;
       uint8_t mask = 0x08;
       uint8_t i = 3;
-      disable();  //  prevent ghost channels.
+      if (disable)
+      {
+        this->disable();  //  prevent ghost channels.
+      }
       while (mask)
       {
         //  only write changed pins. //  AVR only?
@@ -61,6 +65,7 @@ class HC4067
       enable();
       _channel = _new;
     }
+    return true;
   }
 
 

diff --git a/README.md b/README.md
@@ -112,8 +112,16 @@ This will result in another subset of the Y pins to select from.
 - **HC4067(uint8_t s0, uint8_t s1, uint8_t s2, uint8_t s3, uint8_t enablePin = 255)** constructor.
 Set the 4 select pins and optional the enable pin.
 If the enablePin == 255 it is considered not used.
-- **void setChannel(uint8_t channel)** set the current channel.
-Valid values 0..15, this value is not checked, only the lower 4 bits will be used.
+- **bool setChannel(uint8_t channel, bool disable = true)** set the current channel.
+Valid values 0..15, this value is checked (since 0.2.1).
+Returns false if channel out of range.  
+If the channel is already selected it does not change it.
+Note the four channels will not change at the very same moment, 
+possibly resulting in an invalid selection for a (very short) time.  
+The disable flag can be set to false so the device is not disabled during channel switching.
+Default the device is disabled during channel switching to prevent (very short) ghost channels.
+Note that a call to **setChannel()** will always enable the device again.
+Note the device cannot be disabled if there is no enable pin configured.
 - **uint8_t getChannel()** returns the current channel 0..15.
 The selected channel is also returned when the multiplexer is disabled.
 
@@ -122,9 +130,9 @@ The selected channel is also returned when the multiplexer is disabled.
 
 These functions work only if enablePin is set in the constructor.
 
-- **void enable()** enables the HC4067 to multiplex.
-- **void disable()** disables the HC4067, no channel is selected.
-- **bool isEnabled()** returns the current status of the HC4067.
+- **void enable()** enables the device to multiplex.
+- **void disable()** disables the device, no channel is selected.
+- **bool isEnabled()** returns the current status of the device.
 Also returns true if the enablePin is not set in the constructor.
 
 
@@ -146,10 +154,10 @@ Also returns true if the enablePin is not set in the constructor.
 
 #### Won't (unless requested)
 
-- check channel in setChannel() ?
-  - return true if in range, false otherwise.
 - move code to .cpp file
-
+- uint8_t channelCount() { return 16; };
+- cache enable status
+- inline the enable/disable
 
 ## Support
 

diff --git a/examples/HC4067_16_buttons/HC4067_16_buttons.ino b/examples/HC4067_16_buttons/HC4067_16_buttons.ino
@@ -3,6 +3,7 @@
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for HC4067 16 channel (simple) multiplexer
 //          read 16 buttons / switches.
+//     URL: https://github.com/RobTillaart/HC4067
 
 
 #include "HC4067.h"

diff --git a/examples/HC4067_4_channel_plotter/HC4067_4_channel_plotter.ino b/examples/HC4067_4_channel_plotter/HC4067_4_channel_plotter.ino
@@ -2,7 +2,7 @@
 //    FILE: HC4067_4_channel_plotter.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for HC4067 16 channel (simple) multiplexer
-//
+//     URL: https://github.com/RobTillaart/HC4067
 
 //  connect analog channel A0 to the multiplexer
 //  connect 4 analog signals to input 0..3 of the multiplexer

diff --git a/examples/HC4067_demo/HC4067_demo.ino b/examples/HC4067_demo/HC4067_demo.ino
@@ -2,6 +2,7 @@
 //    FILE: HC4067_demo.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for HC4067 16 channel (simple) multiplexer
+//     URL: https://github.com/RobTillaart/HC4067
 
 
 #include "HC4067.h"

diff --git a/examples/HC4067_performance/HC4067_performance.ino b/examples/HC4067_performance/HC4067_performance.ino
@@ -2,11 +2,12 @@
 //    FILE: HC4067_performance.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for HC4067 16 channel (simple) multiplexer
+//     URL: https://github.com/RobTillaart/HC4067
 
 
 #include "HC4067.h"
 
-HC4067 mp(4, 5, 6, 7, 8);
+HC4067 mp(4, 5, 6, 7, 8);  //  enable pin(8)
 
 uint32_t start, stop;
 

diff --git a/examples/HC4067_test/HC4067_test.ino b/examples/HC4067_test/HC4067_test.ino
@@ -2,6 +2,7 @@
 //    FILE: HC4067_test.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for HC4067 16 channel (simple) multiplexer
+//     URL: https://github.com/RobTillaart/HC4067
 
 
 #include "HC4067.h"

diff --git a/examples/HC4067_write/HC4067_write.ino b/examples/HC4067_write/HC4067_write.ino
@@ -2,6 +2,7 @@
 //    FILE: HC4067_write.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for HC4067 16 channel (simple) multiplexer
+//     URL: https://github.com/RobTillaart/HC4067
 
 
 #include "HC4067.h"

diff --git a/keywords.txt b/keywords.txt
@@ -6,6 +6,7 @@ HC4067	KEYWORD1
 # Methods and Functions (KEYWORD2)
 setChannel	KEYWORD2
 getChannel	KEYWORD2
+
 enable	KEYWORD2
 disable	KEYWORD2
 isEnabled	KEYWORD2

diff --git a/library.json b/library.json
@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/HC4067.git"
   },
-  "version": "0.2.0",
+  "version": "0.2.1",
   "license": "MIT",
   "frameworks": "*",
   "platforms": "*",

diff --git a/library.properties b/library.properties
@@ -1,5 +1,5 @@
 name=HC4067
-version=0.2.0
+version=0.2.1
 author=Rob Tillaart <[email protected]>
 maintainer=Rob Tillaart <[email protected]>
 sentence=Arduino library for a HC4067 1 x 16 channel multiplexer