fix #8 ambiguity in call (#9)

- fix #8 ambiguity - update keywords.txt - add example **tca9548_search_device.ino** - update readme.md - prepare error handling (constants) - some minor edits.
RobTillaart · Feb 12, 2023 · 109849b · 109849b
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,15 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
+## [0.1.5] - 2023-02-12
+- fix #8 ambiguity
+- update keywords.txt
+- add example **tca9548_search_device.ino**
+- update readme.md
+- prepare error handling (constants)
+- some minor edits.
+
+
 ## [0.1.4] - 2023-01-23
 - update GitHub actions
 - update license 2023
@@ -15,12 +24,11 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - all channel functions return bool, true on success.
 - minor edits
 
-
 ## [0.1.3] - 2022-11-26
 - Add RP2040 support to build-CI.
 - Add CHANGELOG.md
 - update readme.md
-- move code to .cpp 
+- move code to .cpp
 
 ## [0.1.2] - 2021-12-28
 - update license

diff --git a/README.md b/README.md
@@ -40,7 +40,7 @@ This library is expected to work for the PCA9548(a) too as the TCA is pin compat
 |  PCA9548a  |    n     |
 
 
-There are however small differences, check the datasheets to see the details.
+There are however small differences, check the data sheets to see the details.
 - [difference TCA PCA](https://e2e.ti.com/support/interface-group/interface/f/interface-forum/815758/faq-what-is-the-difference-between-an-i2c-device-with-the-family-name-pca-and-tca)
 - https://electronics.stackexchange.com/questions/209616/is-nxps-pca9548a-compatible-with-tis-tca9548a
 - https://www.nxp.com/docs/en/application-note/AN262.pdf
@@ -100,32 +100,42 @@ Note that writes are only optimized if the channels are already set.
 
 - **void setForced(bool forced = false)** set forced write, slower but more robust.
   - forced == false == fast mode (default).
-  - forced == true == robust mode.
+  - forced == true == slower, robust mode.
 - **bool getForced()** returns set flag.
 
 
+## Error Codes
+
+Not implemented yet, preparation for 0.2.0.
+
+|  name                   |  value  |  description            |
+|:------------------------|:-------:|:------------------------|
+|  TCA9548_OK             |  00     |  no error               |
+|  TCA9548_ERROR_I2C      |  -10    |  detected an I2C error  |
+|  TCA9548_ERROR_CHANNEL  |  -20    |  channel out of range   |
+
+
 ## Future
 
 #### Must
 
 - improve documentation.
-- improve error handling
-
+- improve error handling.
 
 #### Should
 
-- add examples
-- test test and test
-- write unit test
-- create derived classes for compatible devices
-
+- add examples.
+- test test and test.
+- write unit test.
+- create derived classes for compatible devices (0.2.0).
+  - see above PCA9548 and PCA9548a.
+- **bool isConnected(channel, address)**  (0.2.0)
+  - keep previous mask?
 
 #### Could
 
-- set an "always enabled" mask  (have to investigate the consequences)
-- verify channel in range
-  - e.g. **bool enableChannel(uint8_t channel)**, disable(), select()
-
+- set an "always enabled" mask.
+  - investigate the consequences!
 
 #### Wont
 

diff --git a/TCA9548.cpp b/TCA9548.cpp
@@ -1,7 +1,7 @@
 //
 //    FILE: TCA9548.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.4
+// VERSION: 0.1.5
 //    DATE: 2021-03-16
 // PURPOSE: Library for TCA9548 I2C multiplexer
 
@@ -16,7 +16,7 @@ TCA9548::TCA9548(const uint8_t deviceAddress, TwoWire *wire)
   _mask     = 0x00;
   _resetPin = -1;
   _forced   = false;
-  _error    = 0;
+  _error    = TCA9548_OK;
 }
 
 
@@ -118,7 +118,7 @@ uint8_t TCA9548::getChannelMask()
 {
   if (_forced)  //  read from device.
   {
-    _wire->requestFrom(_address, 1);
+    _wire->requestFrom(_address, (uint8_t)1);
     _mask = _wire->read();
   }
   return _mask;
@@ -156,7 +156,7 @@ bool TCA9548::getForced()
 int TCA9548::getError()
 {
   int error = _error;
-  _error = 0;
+  _error = TCA9548_OK;
   return error;
 }
 

diff --git a/TCA9548.h b/TCA9548.h
@@ -2,7 +2,7 @@
 //
 //    FILE: TCA9548.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.4
+// VERSION: 0.1.5
 //    DATE: 2021-03-16
 // PURPOSE: Library for TCA9548 I2C multiplexer
 //     URL: https://github.com/RobTillaart/TCA9548
@@ -12,7 +12,14 @@
 #include "Wire.h"
 
 
-#define TCA9548_LIB_VERSION             (F("0.1.4"))
+#define TCA9548_LIB_VERSION             (F("0.1.5"))
+
+
+//  ERROR CODES (to be elaborated)
+#define TCA9548_OK                      0
+#define TCA9548_ERROR_I2C               -10  //  not used yet
+#define TCA9548_ERROR_CHANNEL           -20  //  not used yet
+
 
 
 class TCA9548
@@ -54,7 +61,7 @@ class TCA9548
 private:
   uint8_t   _address;
   TwoWire*  _wire;
-  uint8_t   _mask;             //  caching mask = status of channels 
+  uint8_t   _mask;             //  caching mask = status of channels
   uint8_t   _resetPin;         //  default not set == -1 (255)
   bool      _forced;
   int       _error;

diff --git a/examples/tca9548_search_device/tca9548_search_device.ino b/examples/tca9548_search_device/tca9548_search_device.ino
@@ -0,0 +1,49 @@
+//
+//    FILE: tca9548_search_device.ino
+//  AUTHOR: Rob Tillaart
+// PURPOSE: demo TCA9548 I2C multiplexer
+//     URL: https://github.com/RobTillaart/TCA9548
+
+
+#include "TCA9548.h"
+
+TCA9548 MP(0x70);
+
+uint8_t searchAddress = 0x38;   //  dummy, adjust to your needs.
+
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println(__FILE__);
+  Serial.println();
+
+  Wire.begin();
+  if (MP.begin() == false)
+  {
+    Serial.println("Could not connect to TCA9548 multiplexer.");
+  }
+
+  Serial.println("\nScan the channels of the multiplexer for searchAddress.\n");
+  for (int chan = 0; chan < 8; chan++)
+  {
+    MP.selectChannel(chan);
+    bool b = MP.isConnected(searchAddress);
+    Serial.print("CHAN: ");
+    Serial.print(chan);
+    Serial.print("\t");
+    Serial.print( b ? "found!" : "x");
+  }
+  Serial.println();
+
+  Serial.println("done...");
+}
+
+
+void loop()
+{
+}
+
+
+//  -- END OF FILE --
+
diff --git a/keywords.txt b/keywords.txt
@@ -12,6 +12,7 @@ enableChannel	KEYWORD2
 disableChannel	KEYWORD2
 selectChannel	KEYWORD2
 isEnabled	KEYWORD2
+disableAllChannels	KEYWORD2
 
 setChannelMask	KEYWORD2
 getChannelMask	KEYWORD2
@@ -28,3 +29,4 @@ getError	KEYWORD2
 # Constants (LITERAL1)
 TCA9548_LIB_VERSION	LITERAL1
 
+TCA9548_OK	LITERAL1
diff --git a/library.json b/library.json
@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/TCA9548"
   },
-  "version": "0.1.4",
+  "version": "0.1.5",
   "license": "MIT",
   "frameworks": "arduino",
   "platforms": "*",

diff --git a/library.properties b/library.properties
@@ -1,11 +1,11 @@
 name=TCA9548
-version=0.1.4
+version=0.1.5
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino Library for TCA9548 I2C multiplexer.
 paragraph=TCA9548, TCA9548a, PCA9548, PCA9548a
 category=Signal Input/Output
 url=https://github.com/RobTillaart/TCA9548
 architectures=*
-includes=TCA9548.h 
+includes=TCA9548.h
 depends=
diff --git a/test/unit_test_001.cpp b/test/unit_test_001.cpp
@@ -61,6 +61,14 @@ unittest_teardown()
 }
 
 
+unittest(test_constants)
+{
+  assertEqual(0,   TCA9548_OK);
+  assertEqual(-10, TCA9548_ERROR_I2C);
+  assertEqual(-20, TCA9548_ERROR_CHANNEL);
+}
+
+
 unittest(test_begin)
 {
   TCA9548 tca(0x70);
@@ -69,7 +77,6 @@ unittest(test_begin)
   assertEqual(b, true);
 
   assertTrue(tca.isConnected());
-
 }
 
 
@@ -113,4 +120,6 @@ unittest(test_select)
 
 unittest_main()
 
-//  -- END OF FILE --
+
+//  -- END OF FILE --
+