diff --git a/README.md b/README.md
index b5894fc7..34717aa7 100644
--- a/README.md
+++ b/README.md
@@ -130,6 +130,7 @@ void setup() {
     sensors.setSeaLevelPressure(1036.25);           // [optional] Set sea level pressure in hpa
     sensors.setDebugMode(false);                    // [optional] debug mode to get detailed msgs
     sensors.detectI2COnly(true);                    // [optional] force to only i2c sensors
+    sensors.setTemperatureUnit(TEMPUNIT::KELVIN);   // comment it for Celsius or set Fahrenheit
     sensors.init();                                 // Auto detection to UART and i2c sensors
 
     // Alternatives only for UART sensors (TX/RX):
@@ -144,8 +145,6 @@ void setup() {
     // sensors.init(SENSORS::SAIRS8);               // Force UART detection to SenseAirS8 CO2 sensor
     // sensors.init(SENSORS::Auto,PMS_RX,PMS_TX);   // Auto detection on custom RX,TX
   
-
-
     // Also you can access to sub-library objects, and perform for example calls like next:
 
     // sensors.sps30.sleep()
diff --git a/doxygen.conf b/doxygen.conf
index 04801c2f..1116469b 100644
--- a/doxygen.conf
+++ b/doxygen.conf
@@ -1,4 +1,4 @@
-# Doxyfile 1.8.13
+# Doxyfile 1.9.1
 
 # This file describes the settings to be used by the documentation system
 # doxygen (www.doxygen.org) for a project.
@@ -17,11 +17,11 @@
 # Project related configuration options
 #---------------------------------------------------------------------------
 
-# This tag specifies the encoding used for all characters in the config file
-# that follow. The default is UTF-8 which is also the encoding used for all text
-# before the first occurrence of this tag. Doxygen uses libiconv (or the iconv
-# built into libc) for the transcoding. See http://www.gnu.org/software/libiconv
-# for the list of possible encodings.
+# This tag specifies the encoding used for all characters in the configuration
+# file that follow. The default is UTF-8 which is also the encoding used for all
+# text before the first occurrence of this tag. Doxygen uses libiconv (or the
+# iconv built into libc) for the transcoding. See
+# https://www.gnu.org/software/libiconv/ for the list of possible encodings.
 # The default value is: UTF-8.
 
 DOXYFILE_ENCODING      = UTF-8
@@ -38,7 +38,7 @@ PROJECT_NAME           = "CanAirIO Sensors Library"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 0.7.0
+PROJECT_NUMBER         = 0.7.1
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a
@@ -93,6 +93,14 @@ ALLOW_UNICODE_NAMES    = NO
 
 OUTPUT_LANGUAGE        = English
 
+# The OUTPUT_TEXT_DIRECTION tag is used to specify the direction in which all
+# documentation generated by doxygen is written. Doxygen will use this
+# information to generate all generated output in the proper direction.
+# Possible values are: None, LTR, RTL and Context.
+# The default value is: None.
+
+OUTPUT_TEXT_DIRECTION  = None
+
 # If the BRIEF_MEMBER_DESC tag is set to YES, doxygen will include brief member
 # descriptions after the members that are listed in the file and class
 # documentation (similar to Javadoc). Set to NO to disable this.
@@ -189,6 +197,16 @@ SHORT_NAMES            = NO
 
 JAVADOC_AUTOBRIEF      = NO
 
+# If the JAVADOC_BANNER tag is set to YES then doxygen will interpret a line
+# such as
+# /***************
+# as being the beginning of a Javadoc-style comment "banner". If set to NO, the
+# Javadoc-style will behave just like regular comments and it will not be
+# interpreted by doxygen.
+# The default value is: NO.
+
+JAVADOC_BANNER         = NO
+
 # If the QT_AUTOBRIEF tag is set to YES then doxygen will interpret the first
 # line (until the first dot) of a Qt-style comment as the brief description. If
 # set to NO, the Qt-style will behave just like regular Qt-style comments (thus
@@ -209,6 +227,14 @@ QT_AUTOBRIEF           = NO
 
 MULTILINE_CPP_IS_BRIEF = NO
 
+# By default Python docstrings are displayed as preformatted text and doxygen's
+# special commands cannot be used. By setting PYTHON_DOCSTRING to NO the
+# doxygen's special commands can be used and the contents of the docstring
+# documentation blocks is shown as doxygen documentation.
+# The default value is: YES.
+
+PYTHON_DOCSTRING       = YES
+
 # If the INHERIT_DOCS tag is set to YES then an undocumented member inherits the
 # documentation from any documented member that it re-implements.
 # The default value is: YES.
@@ -236,16 +262,15 @@ TAB_SIZE               = 4
 # will allow you to put the command \sideeffect (or @sideeffect) in the
 # documentation, which will result in a user-defined paragraph with heading
 # "Side Effects:". You can put \n's in the value part of an alias to insert
-# newlines.
+# newlines (in the resulting output). You can put ^^ in the value part of an
+# alias to insert a newline as if a physical newline was in the original file.
+# When you need a literal { or } or , in the value part of an alias you have to
+# escape them by means of a backslash (\), this can lead to conflicts with the
+# commands \{ and \} for these it is advised to use the version @{ and @} or use
+# a double escape (\\{ and \\})
 
 ALIASES                =
 
-# This tag can be used to specify a number of word-keyword mappings (TCL only).
-# A mapping has the form "name=value". For example adding "class=itcl::class"
-# will allow you to use the command class in the itcl::class meaning.
-
-TCL_SUBST              =
-
 # Set the OPTIMIZE_OUTPUT_FOR_C tag to YES if your project consists of C sources
 # only. Doxygen will then generate output that is more tailored for C. For
 # instance, some of the names that are used will be different. The list of all
@@ -274,28 +299,40 @@ OPTIMIZE_FOR_FORTRAN   = NO
 
 OPTIMIZE_OUTPUT_VHDL   = NO
 
+# Set the OPTIMIZE_OUTPUT_SLICE tag to YES if your project consists of Slice
+# sources only. Doxygen will then generate output that is more tailored for that
+# language. For instance, namespaces will be presented as modules, types will be
+# separated into more groups, etc.
+# The default value is: NO.
+
+OPTIMIZE_OUTPUT_SLICE  = NO
+
 # Doxygen selects the parser to use depending on the extension of the files it
 # parses. With this tag you can assign which parser to use for a given
 # extension. Doxygen has a built-in mapping, but you can override or extend it
 # using this tag. The format is ext=language, where ext is a file extension, and
-# language is one of the parsers supported by doxygen: IDL, Java, Javascript,
-# C#, C, C++, D, PHP, Objective-C, Python, Fortran (fixed format Fortran:
-# FortranFixed, free formatted Fortran: FortranFree, unknown formatted Fortran:
-# Fortran. In the later case the parser tries to guess whether the code is fixed
-# or free formatted code, this is the default for Fortran type files), VHDL. For
-# instance to make doxygen treat .inc files as Fortran files (default is PHP),
-# and .f files as C (default is Fortran), use: inc=Fortran f=C.
+# language is one of the parsers supported by doxygen: IDL, Java, JavaScript,
+# Csharp (C#), C, C++, D, PHP, md (Markdown), Objective-C, Python, Slice, VHDL,
+# Fortran (fixed format Fortran: FortranFixed, free formatted Fortran:
+# FortranFree, unknown formatted Fortran: Fortran. In the later case the parser
+# tries to guess whether the code is fixed or free formatted code, this is the
+# default for Fortran type files). For instance to make doxygen treat .inc files
+# as Fortran files (default is PHP), and .f files as C (default is Fortran),
+# use: inc=Fortran f=C.
 #
 # Note: For files without extension you can use no_extension as a placeholder.
 #
 # Note that for custom extensions you also need to set FILE_PATTERNS otherwise
-# the files are not read by doxygen.
+# the files are not read by doxygen. When specifying no_extension you should add
+# * to the FILE_PATTERNS.
+#
+# Note see also the list of default file extension mappings.
 
 EXTENSION_MAPPING      =
 
 # If the MARKDOWN_SUPPORT tag is enabled then doxygen pre-processes all comments
 # according to the Markdown format, which allows for more readable
-# documentation. See http://daringfireball.net/projects/markdown/ for details.
+# documentation. See https://daringfireball.net/projects/markdown/ for details.
 # The output of markdown processing is further processed by doxygen, so you can
 # mix doxygen, HTML, and XML commands with Markdown formatting. Disable only in
 # case of backward compatibilities issues.
@@ -307,7 +344,7 @@ MARKDOWN_SUPPORT       = YES
 # to that level are automatically included in the table of contents, even if
 # they do not have an id attribute.
 # Note: This feature currently applies only to Markdown headings.
-# Minimum value: 0, maximum value: 99, default value: 0.
+# Minimum value: 0, maximum value: 99, default value: 5.
 # This tag requires that the tag MARKDOWN_SUPPORT is set to YES.
 
 TOC_INCLUDE_HEADINGS   = 0
@@ -337,7 +374,7 @@ BUILTIN_STL_SUPPORT    = NO
 CPP_CLI_SUPPORT        = NO
 
 # Set the SIP_SUPPORT tag to YES if your project consists of sip (see:
-# http://www.riverbankcomputing.co.uk/software/sip/intro) sources only. Doxygen
+# https://www.riverbankcomputing.com/software/sip/intro) sources only. Doxygen
 # will parse them like normal C++ but will assume all classes use public instead
 # of private inheritance when no explicit protection keyword is present.
 # The default value is: NO.
@@ -423,6 +460,19 @@ TYPEDEF_HIDES_STRUCT   = NO
 
 LOOKUP_CACHE_SIZE      = 0
 
+# The NUM_PROC_THREADS specifies the number threads doxygen is allowed to use
+# during processing. When set to 0 doxygen will based this on the number of
+# cores available in the system. You can set it explicitly to a value larger
+# than 0 to get more control over the balance between CPU load and processing
+# speed. At this moment only the input processing can be done using multiple
+# threads. Since this is still an experimental feature the default is set to 1,
+# which efficively disables parallel processing. Please report any issues you
+# encounter. Generating dot graphs in parallel is controlled by the
+# DOT_NUM_THREADS setting.
+# Minimum value: 0, maximum value: 32, default value: 1.
+
+NUM_PROC_THREADS       = 1
+
 #---------------------------------------------------------------------------
 # Build related configuration options
 #---------------------------------------------------------------------------
@@ -443,6 +493,12 @@ EXTRACT_ALL            = NO
 
 EXTRACT_PRIVATE        = NO
 
+# If the EXTRACT_PRIV_VIRTUAL tag is set to YES, documented private virtual
+# methods of a class will be included in the documentation.
+# The default value is: NO.
+
+EXTRACT_PRIV_VIRTUAL   = NO
+
 # If the EXTRACT_PACKAGE tag is set to YES, all members with package or internal
 # scope will be included in the documentation.
 # The default value is: NO.
@@ -480,6 +536,13 @@ EXTRACT_LOCAL_METHODS  = NO
 
 EXTRACT_ANON_NSPACES   = NO
 
+# If this flag is set to YES, the name of an unnamed parameter in a declaration
+# will be determined by the corresponding definition. By default unnamed
+# parameters remain unnamed in the output.
+# The default value is: YES.
+
+RESOLVE_UNNAMED_PARAMS = YES
+
 # If the HIDE_UNDOC_MEMBERS tag is set to YES, doxygen will hide all
 # undocumented members inside documented classes or files. If set to NO these
 # members will be included in the various overviews, but no documentation
@@ -497,8 +560,8 @@ HIDE_UNDOC_MEMBERS     = NO
 HIDE_UNDOC_CLASSES     = NO
 
 # If the HIDE_FRIEND_COMPOUNDS tag is set to YES, doxygen will hide all friend
-# (class|struct|union) declarations. If set to NO, these declarations will be
-# included in the documentation.
+# declarations. If set to NO, these declarations will be included in the
+# documentation.
 # The default value is: NO.
 
 HIDE_FRIEND_COMPOUNDS  = NO
@@ -517,11 +580,18 @@ HIDE_IN_BODY_DOCS      = NO
 
 INTERNAL_DOCS          = NO
 
-# If the CASE_SENSE_NAMES tag is set to NO then doxygen will only generate file
-# names in lower-case letters. If set to YES, upper-case letters are also
-# allowed. This is useful if you have classes or files whose names only differ
-# in case and if your file system supports case sensitive file names. Windows
-# and Mac users are advised to set this option to NO.
+# With the correct setting of option CASE_SENSE_NAMES doxygen will better be
+# able to match the capabilities of the underlying filesystem. In case the
+# filesystem is case sensitive (i.e. it supports files in the same directory
+# whose names only differ in casing), the option must be set to YES to properly
+# deal with such files in case they appear in the input. For filesystems that
+# are not case sensitive the option should be be set to NO to properly deal with
+# output files written for symbols that only differ in casing, such as for two
+# classes, one named CLASS and the other named Class, and to also support
+# references to files without having to specify the exact matching casing. On
+# Windows (including Cygwin) and MacOS, users should typically set this option
+# to NO, whereas on Linux or other Unix flavors it should typically be set to
+# YES.
 # The default value is: system dependent.
 
 CASE_SENSE_NAMES       = YES
@@ -708,7 +778,7 @@ LAYOUT_FILE            =
 # The CITE_BIB_FILES tag can be used to specify one or more bib files containing
 # the reference definitions. This must be a list of .bib files. The .bib
 # extension is automatically appended if omitted. This requires the bibtex tool
-# to be installed. See also http://en.wikipedia.org/wiki/BibTeX for more info.
+# to be installed. See also https://en.wikipedia.org/wiki/BibTeX for more info.
 # For LaTeX the style of the bibliography can be controlled using
 # LATEX_BIB_STYLE. To use this feature you need bibtex and perl available in the
 # search path. See also \cite for info how to create references.
@@ -753,13 +823,17 @@ WARN_IF_DOC_ERROR      = YES
 # This WARN_NO_PARAMDOC option can be enabled to get warnings for functions that
 # are documented, but have no documentation for their parameters or return
 # value. If set to NO, doxygen will only warn about wrong or incomplete
-# parameter documentation, but not about the absence of documentation.
+# parameter documentation, but not about the absence of documentation. If
+# EXTRACT_ALL is set to YES then this flag will automatically be disabled.
 # The default value is: NO.
 
 WARN_NO_PARAMDOC       = NO
 
 # If the WARN_AS_ERROR tag is set to YES then doxygen will immediately stop when
-# a warning is encountered.
+# a warning is encountered. If the WARN_AS_ERROR tag is set to FAIL_ON_WARNINGS
+# then doxygen will continue running as if WARN_AS_ERROR tag is set to NO, but
+# at the end of the doxygen process doxygen will return with a non-zero status.
+# Possible values are: NO, YES and FAIL_ON_WARNINGS.
 # The default value is: NO.
 
 WARN_AS_ERROR          = NO
@@ -790,13 +864,14 @@ WARN_LOGFILE           =
 # spaces. See also FILE_PATTERNS and EXTENSION_MAPPING
 # Note: If this tag is empty the current directory is searched.
 
-INPUT                  = src README.md
+INPUT                  = src \
+                         README.md
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
 # libiconv (or the iconv built into libc) for the transcoding. See the libiconv
-# documentation (see: http://www.gnu.org/software/libiconv) for the list of
-# possible encodings.
+# documentation (see:
+# https://www.gnu.org/software/libiconv/) for the list of possible encodings.
 # The default value is: UTF-8.
 
 INPUT_ENCODING         = UTF-8
@@ -809,11 +884,15 @@ INPUT_ENCODING         = UTF-8
 # need to set EXTENSION_MAPPING for the extension otherwise the files are not
 # read by doxygen.
 #
+# Note the list of default checked file patterns might differ from the list of
+# default file extension mappings.
+#
 # If left blank the following patterns are tested:*.c, *.cc, *.cxx, *.cpp,
 # *.c++, *.java, *.ii, *.ixx, *.ipp, *.i++, *.inl, *.idl, *.ddl, *.odl, *.h,
 # *.hh, *.hxx, *.hpp, *.h++, *.cs, *.d, *.php, *.php4, *.php5, *.phtml, *.inc,
-# *.m, *.markdown, *.md, *.mm, *.dox, *.py, *.pyw, *.f90, *.f95, *.f03, *.f08,
-# *.f, *.for, *.tcl, *.vhd, *.vhdl, *.ucf and *.qsf.
+# *.m, *.markdown, *.md, *.mm, *.dox (to be provided as doxygen C comment),
+# *.py, *.pyw, *.f90, *.f95, *.f03, *.f08, *.f18, *.f, *.for, *.vhd, *.vhdl,
+# *.ucf, *.qsf and *.ice.
 
 FILE_PATTERNS          = *.c \
                          *.cc \
@@ -1011,7 +1090,7 @@ INLINE_SOURCES         = NO
 STRIP_CODE_COMMENTS    = YES
 
 # If the REFERENCED_BY_RELATION tag is set to YES then for each documented
-# function all documented functions referencing it will be listed.
+# entity all documented functions referencing it will be listed.
 # The default value is: NO.
 
 REFERENCED_BY_RELATION = NO
@@ -1043,12 +1122,12 @@ SOURCE_TOOLTIPS        = YES
 # If the USE_HTAGS tag is set to YES then the references to source code will
 # point to the HTML generated by the htags(1) tool instead of doxygen built-in
 # source browser. The htags tool is part of GNU's global source tagging system
-# (see http://www.gnu.org/software/global/global.html). You will need version
+# (see https://www.gnu.org/software/global/global.html). You will need version
 # 4.8.6 or higher.
 #
 # To use it do the following:
 # - Install the latest version of global
-# - Enable SOURCE_BROWSER and USE_HTAGS in the config file
+# - Enable SOURCE_BROWSER and USE_HTAGS in the configuration file
 # - Make sure the INPUT points to the root of the source tree
 # - Run doxygen as normal
 #
@@ -1071,16 +1150,22 @@ USE_HTAGS              = NO
 VERBATIM_HEADERS       = YES
 
 # If the CLANG_ASSISTED_PARSING tag is set to YES then doxygen will use the
-# clang parser (see: http://clang.llvm.org/) for more accurate parsing at the
-# cost of reduced performance. This can be particularly helpful with template
-# rich C++ code for which doxygen's built-in parser lacks the necessary type
-# information.
+# clang parser (see:
+# http://clang.llvm.org/) for more accurate parsing at the cost of reduced
+# performance. This can be particularly helpful with template rich C++ code for
+# which doxygen's built-in parser lacks the necessary type information.
 # Note: The availability of this option depends on whether or not doxygen was
-# generated with the -Duse-libclang=ON option for CMake.
+# generated with the -Duse_libclang=ON option for CMake.
 # The default value is: NO.
 
 CLANG_ASSISTED_PARSING = NO
 
+# If clang assisted parsing is enabled and the CLANG_ADD_INC_PATHS tag is set to
+# YES then doxygen will add the directory of each input to the include path.
+# The default value is: YES.
+
+CLANG_ADD_INC_PATHS    = YES
+
 # If clang assisted parsing is enabled you can provide the compiler with command
 # line options that you would normally use when invoking the compiler. Note that
 # the include paths will already be set by doxygen for the files and directories
@@ -1089,6 +1174,19 @@ CLANG_ASSISTED_PARSING = NO
 
 CLANG_OPTIONS          =
 
+# If clang assisted parsing is enabled you can provide the clang parser with the
+# path to the directory containing a file called compile_commands.json. This
+# file is the compilation database (see:
+# http://clang.llvm.org/docs/HowToSetupToolingForLLVM.html) containing the
+# options used when the source files were built. This is equivalent to
+# specifying the -p option to a clang tool, such as clang-check. These options
+# will then be passed to the parser. Any options specified with CLANG_OPTIONS
+# will be added as well.
+# Note: The availability of this option depends on whether or not doxygen was
+# generated with the -Duse_libclang=ON option for CMake.
+
+CLANG_DATABASE_PATH    =
+
 #---------------------------------------------------------------------------
 # Configuration options related to the alphabetical class index
 #---------------------------------------------------------------------------
@@ -1100,13 +1198,6 @@ CLANG_OPTIONS          =
 
 ALPHABETICAL_INDEX     = YES
 
-# The COLS_IN_ALPHA_INDEX tag can be used to specify the number of columns in
-# which the alphabetical index list will be split.
-# Minimum value: 1, maximum value: 20, default value: 5.
-# This tag requires that the tag ALPHABETICAL_INDEX is set to YES.
-
-COLS_IN_ALPHA_INDEX    = 5
-
 # In case all classes in a project start with a common prefix, all classes will
 # be put under the same header in the alphabetical index. The IGNORE_PREFIX tag
 # can be used to specify a prefix (or a list of prefixes) that should be ignored
@@ -1207,7 +1298,7 @@ HTML_EXTRA_FILES       =
 # The HTML_COLORSTYLE_HUE tag controls the color of the HTML output. Doxygen
 # will adjust the colors in the style sheet and background images according to
 # this color. Hue is specified as an angle on a colorwheel, see
-# http://en.wikipedia.org/wiki/Hue for more information. For instance the value
+# https://en.wikipedia.org/wiki/Hue for more information. For instance the value
 # 0 represents red, 60 is yellow, 120 is green, 180 is cyan, 240 is blue, 300
 # purple, and 360 is red again.
 # Minimum value: 0, maximum value: 359, default value: 220.
@@ -1243,6 +1334,17 @@ HTML_COLORSTYLE_GAMMA  = 80
 
 HTML_TIMESTAMP         = NO
 
+# If the HTML_DYNAMIC_MENUS tag is set to YES then the generated HTML
+# documentation will contain a main index with vertical navigation menus that
+# are dynamically created via JavaScript. If disabled, the navigation index will
+# consists of multiple levels of tabs that are statically embedded in every HTML
+# page. Disable this option to support browsers that do not have JavaScript,
+# like the Qt help browser.
+# The default value is: YES.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_DYNAMIC_MENUS     = YES
+
 # If the HTML_DYNAMIC_SECTIONS tag is set to YES then the generated HTML
 # documentation will contain sections that can be hidden and shown after the
 # page has loaded.
@@ -1266,13 +1368,14 @@ HTML_INDEX_NUM_ENTRIES = 100
 
 # If the GENERATE_DOCSET tag is set to YES, additional index files will be
 # generated that can be used as input for Apple's Xcode 3 integrated development
-# environment (see: http://developer.apple.com/tools/xcode/), introduced with
-# OSX 10.5 (Leopard). To create a documentation set, doxygen will generate a
-# Makefile in the HTML output directory. Running make will produce the docset in
-# that directory and running make install will install the docset in
+# environment (see:
+# https://developer.apple.com/xcode/), introduced with OSX 10.5 (Leopard). To
+# create a documentation set, doxygen will generate a Makefile in the HTML
+# output directory. Running make will produce the docset in that directory and
+# running make install will install the docset in
 # ~/Library/Developer/Shared/Documentation/DocSets so that Xcode will find it at
-# startup. See http://developer.apple.com/tools/creatingdocsetswithdoxygen.html
-# for more information.
+# startup. See https://developer.apple.com/library/archive/featuredarticles/Doxy
+# genXcode/_index.html for more information.
 # The default value is: NO.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
@@ -1311,8 +1414,8 @@ DOCSET_PUBLISHER_NAME  = Publisher
 # If the GENERATE_HTMLHELP tag is set to YES then doxygen generates three
 # additional HTML index files: index.hhp, index.hhc, and index.hhk. The
 # index.hhp is a project file that can be read by Microsoft's HTML Help Workshop
-# (see: http://www.microsoft.com/en-us/download/details.aspx?id=21138) on
-# Windows.
+# (see:
+# https://www.microsoft.com/en-us/download/details.aspx?id=21138) on Windows.
 #
 # The HTML Help Workshop contains a compiler that can convert all HTML output
 # generated by doxygen into a single compiled HTML file (.chm). Compiled HTML
@@ -1342,7 +1445,7 @@ CHM_FILE               =
 HHC_LOCATION           =
 
 # The GENERATE_CHI flag controls if a separate .chi index file is generated
-# (YES) or that it should be included in the master .chm file (NO).
+# (YES) or that it should be included in the main .chm file (NO).
 # The default value is: NO.
 # This tag requires that the tag GENERATE_HTMLHELP is set to YES.
 
@@ -1387,7 +1490,8 @@ QCH_FILE               =
 
 # The QHP_NAMESPACE tag specifies the namespace to use when generating Qt Help
 # Project output. For more information please see Qt Help Project / Namespace
-# (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#namespace).
+# (see:
+# https://doc.qt.io/archives/qt-4.8/qthelpproject.html#namespace).
 # The default value is: org.doxygen.Project.
 # This tag requires that the tag GENERATE_QHP is set to YES.
 
@@ -1395,8 +1499,8 @@ QHP_NAMESPACE          = org.doxygen.Project
 
 # The QHP_VIRTUAL_FOLDER tag specifies the namespace to use when generating Qt
 # Help Project output. For more information please see Qt Help Project / Virtual
-# Folders (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#virtual-
-# folders).
+# Folders (see:
+# https://doc.qt.io/archives/qt-4.8/qthelpproject.html#virtual-folders).
 # The default value is: doc.
 # This tag requires that the tag GENERATE_QHP is set to YES.
 
@@ -1404,30 +1508,30 @@ QHP_VIRTUAL_FOLDER     = doc
 
 # If the QHP_CUST_FILTER_NAME tag is set, it specifies the name of a custom
 # filter to add. For more information please see Qt Help Project / Custom
-# Filters (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#custom-
-# filters).
+# Filters (see:
+# https://doc.qt.io/archives/qt-4.8/qthelpproject.html#custom-filters).
 # This tag requires that the tag GENERATE_QHP is set to YES.
 
 QHP_CUST_FILTER_NAME   =
 
 # The QHP_CUST_FILTER_ATTRS tag specifies the list of the attributes of the
 # custom filter to add. For more information please see Qt Help Project / Custom
-# Filters (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#custom-
-# filters).
+# Filters (see:
+# https://doc.qt.io/archives/qt-4.8/qthelpproject.html#custom-filters).
 # This tag requires that the tag GENERATE_QHP is set to YES.
 
 QHP_CUST_FILTER_ATTRS  =
 
 # The QHP_SECT_FILTER_ATTRS tag specifies the list of the attributes this
 # project's filter section matches. Qt Help Project / Filter Attributes (see:
-# http://qt-project.org/doc/qt-4.8/qthelpproject.html#filter-attributes).
+# https://doc.qt.io/archives/qt-4.8/qthelpproject.html#filter-attributes).
 # This tag requires that the tag GENERATE_QHP is set to YES.
 
 QHP_SECT_FILTER_ATTRS  =
 
-# The QHG_LOCATION tag can be used to specify the location of Qt's
-# qhelpgenerator. If non-empty doxygen will try to run qhelpgenerator on the
-# generated .qhp file.
+# The QHG_LOCATION tag can be used to specify the location (absolute path
+# including file name) of Qt's qhelpgenerator. If non-empty doxygen will try to
+# run qhelpgenerator on the generated .qhp file.
 # This tag requires that the tag GENERATE_QHP is set to YES.
 
 QHG_LOCATION           =
@@ -1504,6 +1608,17 @@ TREEVIEW_WIDTH         = 250
 
 EXT_LINKS_IN_WINDOW    = NO
 
+# If the HTML_FORMULA_FORMAT option is set to svg, doxygen will use the pdf2svg
+# tool (see https://github.com/dawbarton/pdf2svg) or inkscape (see
+# https://inkscape.org) to generate formulas as SVG images instead of PNGs for
+# the HTML output. These images will generally look nicer at scaled resolutions.
+# Possible values are: png (the default) and svg (looks nicer but requires the
+# pdf2svg or inkscape tool).
+# The default value is: png.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_FORMULA_FORMAT    = png
+
 # Use this tag to change the font size of LaTeX formulas included as images in
 # the HTML documentation. When you change the font size after a successful
 # doxygen run you need to manually remove any form_*.png images from the HTML
@@ -1513,7 +1628,7 @@ EXT_LINKS_IN_WINDOW    = NO
 
 FORMULA_FONTSIZE       = 10
 
-# Use the FORMULA_TRANPARENT tag to determine whether or not the images
+# Use the FORMULA_TRANSPARENT tag to determine whether or not the images
 # generated for formulas are transparent PNGs. Transparent PNGs are not
 # supported properly for IE 6.0, but are supported on all modern browsers.
 #
@@ -1524,8 +1639,14 @@ FORMULA_FONTSIZE       = 10
 
 FORMULA_TRANSPARENT    = YES
 
+# The FORMULA_MACROFILE can contain LaTeX \newcommand and \renewcommand commands
+# to create new LaTeX commands to be used in formulas as building blocks. See
+# the section "Including formulas" for details.
+
+FORMULA_MACROFILE      =
+
 # Enable the USE_MATHJAX option to render LaTeX formulas using MathJax (see
-# http://www.mathjax.org) which uses client side Javascript for the rendering
+# https://www.mathjax.org) which uses client side JavaScript for the rendering
 # instead of using pre-rendered bitmaps. Use this if you do not have LaTeX
 # installed or if you want to formulas look prettier in the HTML output. When
 # enabled you may also need to install MathJax separately and configure the path
@@ -1537,7 +1658,7 @@ USE_MATHJAX            = NO
 
 # When MathJax is enabled you can set the default output format to be used for
 # the MathJax output. See the MathJax site (see:
-# http://docs.mathjax.org/en/latest/output.html) for more details.
+# http://docs.mathjax.org/en/v2.7-latest/output.html) for more details.
 # Possible values are: HTML-CSS (which is slower, but has the best
 # compatibility), NativeMML (i.e. MathML) and SVG.
 # The default value is: HTML-CSS.
@@ -1552,8 +1673,8 @@ MATHJAX_FORMAT         = HTML-CSS
 # MATHJAX_RELPATH should be ../mathjax. The default value points to the MathJax
 # Content Delivery Network so you can quickly see the result without installing
 # MathJax. However, it is strongly recommended to install a local copy of
-# MathJax from http://www.mathjax.org before deployment.
-# The default value is: http://cdn.mathjax.org/mathjax/latest.
+# MathJax from https://www.mathjax.org before deployment.
+# The default value is: https://cdn.jsdelivr.net/npm/mathjax@2.
 # This tag requires that the tag USE_MATHJAX is set to YES.
 
 MATHJAX_RELPATH        = http://cdn.mathjax.org/mathjax/latest
@@ -1567,7 +1688,8 @@ MATHJAX_EXTENSIONS     =
 
 # The MATHJAX_CODEFILE tag can be used to specify a file with javascript pieces
 # of code that will be used on startup of the MathJax code. See the MathJax site
-# (see: http://docs.mathjax.org/en/latest/output.html) for more details. For an
+# (see:
+# http://docs.mathjax.org/en/v2.7-latest/output.html) for more details. For an
 # example see the documentation.
 # This tag requires that the tag USE_MATHJAX is set to YES.
 
@@ -1595,7 +1717,7 @@ MATHJAX_CODEFILE       =
 SEARCHENGINE           = YES
 
 # When the SERVER_BASED_SEARCH tag is enabled the search engine will be
-# implemented using a web server instead of a web client using Javascript. There
+# implemented using a web server instead of a web client using JavaScript. There
 # are two flavors of web server based searching depending on the EXTERNAL_SEARCH
 # setting. When disabled, doxygen will generate a PHP script for searching and
 # an index file used by the script. When EXTERNAL_SEARCH is enabled the indexing
@@ -1614,7 +1736,8 @@ SERVER_BASED_SEARCH    = NO
 #
 # Doxygen ships with an example indexer (doxyindexer) and search engine
 # (doxysearch.cgi) which are based on the open source search engine library
-# Xapian (see: http://xapian.org/).
+# Xapian (see:
+# https://xapian.org/).
 #
 # See the section "External Indexing and Searching" for details.
 # The default value is: NO.
@@ -1627,8 +1750,9 @@ EXTERNAL_SEARCH        = NO
 #
 # Doxygen ships with an example indexer (doxyindexer) and search engine
 # (doxysearch.cgi) which are based on the open source search engine library
-# Xapian (see: http://xapian.org/). See the section "External Indexing and
-# Searching" for details.
+# Xapian (see:
+# https://xapian.org/). See the section "External Indexing and Searching" for
+# details.
 # This tag requires that the tag SEARCHENGINE is set to YES.
 
 SEARCHENGINE_URL       =
@@ -1679,21 +1803,35 @@ LATEX_OUTPUT           = latex
 # The LATEX_CMD_NAME tag can be used to specify the LaTeX command name to be
 # invoked.
 #
-# Note that when enabling USE_PDFLATEX this option is only used for generating
-# bitmaps for formulas in the HTML output, but not in the Makefile that is
-# written to the output directory.
-# The default file is: latex.
+# Note that when not enabling USE_PDFLATEX the default is latex when enabling
+# USE_PDFLATEX the default is pdflatex and when in the later case latex is
+# chosen this is overwritten by pdflatex. For specific output languages the
+# default can have been set differently, this depends on the implementation of
+# the output language.
 # This tag requires that the tag GENERATE_LATEX is set to YES.
 
 LATEX_CMD_NAME         = latex
 
 # The MAKEINDEX_CMD_NAME tag can be used to specify the command name to generate
 # index for LaTeX.
+# Note: This tag is used in the Makefile / make.bat.
+# See also: LATEX_MAKEINDEX_CMD for the part in the generated output file
+# (.tex).
 # The default file is: makeindex.
 # This tag requires that the tag GENERATE_LATEX is set to YES.
 
 MAKEINDEX_CMD_NAME     = makeindex
 
+# The LATEX_MAKEINDEX_CMD tag can be used to specify the command name to
+# generate index for LaTeX. In case there is no backslash (\) as first character
+# it will be automatically added in the LaTeX code.
+# Note: This tag is used in the generated output file (.tex).
+# See also: MAKEINDEX_CMD_NAME for the part in the Makefile / make.bat.
+# The default value is: makeindex.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+LATEX_MAKEINDEX_CMD    = makeindex
+
 # If the COMPACT_LATEX tag is set to YES, doxygen generates more compact LaTeX
 # documents. This may be useful for small projects and may help to save some
 # trees in general.
@@ -1778,9 +1916,11 @@ LATEX_EXTRA_FILES      =
 
 PDF_HYPERLINKS         = YES
 
-# If the USE_PDFLATEX tag is set to YES, doxygen will use pdflatex to generate
-# the PDF file directly from the LaTeX files. Set this option to YES, to get a
-# higher quality PDF documentation.
+# If the USE_PDFLATEX tag is set to YES, doxygen will use the engine as
+# specified with LATEX_CMD_NAME to generate the PDF file directly from the LaTeX
+# files. Set this option to YES, to get a higher quality PDF documentation.
+#
+# See also section LATEX_CMD_NAME for selecting the engine.
 # The default value is: YES.
 # This tag requires that the tag GENERATE_LATEX is set to YES.
 
@@ -1814,7 +1954,7 @@ LATEX_SOURCE_CODE      = NO
 
 # The LATEX_BIB_STYLE tag can be used to specify the style to use for the
 # bibliography, e.g. plainnat, or ieeetr. See
-# http://en.wikipedia.org/wiki/BibTeX and \cite for more info.
+# https://en.wikipedia.org/wiki/BibTeX and \cite for more info.
 # The default value is: plain.
 # This tag requires that the tag GENERATE_LATEX is set to YES.
 
@@ -1828,6 +1968,14 @@ LATEX_BIB_STYLE        = plain
 
 LATEX_TIMESTAMP        = NO
 
+# The LATEX_EMOJI_DIRECTORY tag is used to specify the (relative or absolute)
+# path from which the emoji images will be read. If a relative path is entered,
+# it will be relative to the LATEX_OUTPUT directory. If left blank the
+# LATEX_OUTPUT directory will be used.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+LATEX_EMOJI_DIRECTORY  =
+
 #---------------------------------------------------------------------------
 # Configuration options related to the RTF output
 #---------------------------------------------------------------------------
@@ -1867,9 +2015,9 @@ COMPACT_RTF            = NO
 
 RTF_HYPERLINKS         = NO
 
-# Load stylesheet definitions from file. Syntax is similar to doxygen's config
-# file, i.e. a series of assignments. You only have to provide replacements,
-# missing definitions are set to their default value.
+# Load stylesheet definitions from file. Syntax is similar to doxygen's
+# configuration file, i.e. a series of assignments. You only have to provide
+# replacements, missing definitions are set to their default value.
 #
 # See also section "Doxygen usage" for information on how to generate the
 # default style sheet that doxygen normally uses.
@@ -1878,8 +2026,8 @@ RTF_HYPERLINKS         = NO
 RTF_STYLESHEET_FILE    =
 
 # Set optional variables used in the generation of an RTF document. Syntax is
-# similar to doxygen's config file. A template extensions file can be generated
-# using doxygen -e rtf extensionFile.
+# similar to doxygen's configuration file. A template extensions file can be
+# generated using doxygen -e rtf extensionFile.
 # This tag requires that the tag GENERATE_RTF is set to YES.
 
 RTF_EXTENSIONS_FILE    =
@@ -1965,6 +2113,13 @@ XML_OUTPUT             = xml
 
 XML_PROGRAMLISTING     = YES
 
+# If the XML_NS_MEMB_FILE_SCOPE tag is set to YES, doxygen will include
+# namespace members in file scope as well, matching the HTML output.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_XML is set to YES.
+
+XML_NS_MEMB_FILE_SCOPE = NO
+
 #---------------------------------------------------------------------------
 # Configuration options related to the DOCBOOK output
 #---------------------------------------------------------------------------
@@ -1997,9 +2152,9 @@ DOCBOOK_PROGRAMLISTING = NO
 #---------------------------------------------------------------------------
 
 # If the GENERATE_AUTOGEN_DEF tag is set to YES, doxygen will generate an
-# AutoGen Definitions (see http://autogen.sf.net) file that captures the
-# structure of the code including all documentation. Note that this feature is
-# still experimental and incomplete at the moment.
+# AutoGen Definitions (see http://autogen.sourceforge.net/) file that captures
+# the structure of the code including all documentation. Note that this feature
+# is still experimental and incomplete at the moment.
 # The default value is: NO.
 
 GENERATE_AUTOGEN_DEF   = NO
@@ -2166,12 +2321,6 @@ EXTERNAL_GROUPS        = YES
 
 EXTERNAL_PAGES         = YES
 
-# The PERL_PATH should be the absolute path and name of the perl script
-# interpreter (i.e. the result of 'which perl').
-# The default file (with absolute path) is: /usr/bin/perl.
-
-PERL_PATH              = /usr/bin/perl
-
 #---------------------------------------------------------------------------
 # Configuration options related to the dot tool
 #---------------------------------------------------------------------------
@@ -2185,15 +2334,6 @@ PERL_PATH              = /usr/bin/perl
 
 CLASS_DIAGRAMS         = YES
 
-# You can define message sequence charts within doxygen comments using the \msc
-# command. Doxygen will then run the mscgen tool (see:
-# http://www.mcternan.me.uk/mscgen/)) to produce the chart and insert it in the
-# documentation. The MSCGEN_PATH tag allows you to specify the directory where
-# the mscgen tool resides. If left empty the tool is assumed to be found in the
-# default search path.
-
-MSCGEN_PATH            =
-
 # You can include diagrams made with dia in doxygen documentation. Doxygen will
 # then run dia to produce the diagram and insert it in the documentation. The
 # DIA_PATH tag allows you to specify the directory where the dia binary resides.
@@ -2291,10 +2431,32 @@ UML_LOOK               = NO
 # but if the number exceeds 15, the total amount of fields shown is limited to
 # 10.
 # Minimum value: 0, maximum value: 100, default value: 10.
-# This tag requires that the tag HAVE_DOT is set to YES.
+# This tag requires that the tag UML_LOOK is set to YES.
 
 UML_LIMIT_NUM_FIELDS   = 10
 
+# If the DOT_UML_DETAILS tag is set to NO, doxygen will show attributes and
+# methods without types and arguments in the UML graphs. If the DOT_UML_DETAILS
+# tag is set to YES, doxygen will add type and arguments for attributes and
+# methods in the UML graphs. If the DOT_UML_DETAILS tag is set to NONE, doxygen
+# will not generate fields with class member information in the UML graphs. The
+# class diagrams will look similar to the default class diagrams but using UML
+# notation for the relationships.
+# Possible values are: NO, YES and NONE.
+# The default value is: NO.
+# This tag requires that the tag UML_LOOK is set to YES.
+
+DOT_UML_DETAILS        = NO
+
+# The DOT_WRAP_THRESHOLD tag can be used to set the maximum number of characters
+# to display on a single line. If the actual line length exceeds this threshold
+# significantly it will wrapped across multiple lines. Some heuristics are apply
+# to avoid ugly line breaks.
+# Minimum value: 0, maximum value: 1000, default value: 17.
+# This tag requires that the tag HAVE_DOT is set to YES.
+
+DOT_WRAP_THRESHOLD     = 17
+
 # If the TEMPLATE_RELATIONS tag is set to YES then the inheritance and
 # collaboration graphs will show the relations between templates and their
 # instances.
@@ -2486,9 +2648,18 @@ DOT_MULTI_TARGETS      = NO
 
 GENERATE_LEGEND        = YES
 
-# If the DOT_CLEANUP tag is set to YES, doxygen will remove the intermediate dot
+# If the DOT_CLEANUP tag is set to YES, doxygen will remove the intermediate
 # files that are used to generate the various graphs.
+#
+# Note: This setting is not only used for dot files but also for msc and
+# plantuml temporary files.
 # The default value is: YES.
-# This tag requires that the tag HAVE_DOT is set to YES.
 
 DOT_CLEANUP            = YES
+
+# MODS:
+
+
+DISABLE_INDEX = YES
+GENERATE_TREEVIEW = YES
+
diff --git a/src/Sensors.cpp b/src/Sensors.cpp
index 881de94f..897c4c6b 100644
--- a/src/Sensors.cpp
+++ b/src/Sensors.cpp
@@ -194,7 +194,7 @@ void Sensors::setCO2RecalibrationFactor(int ppmValue) {
  */
 void Sensors::setCO2AltitudeOffset(float altitude){
     this->altoffset = altitude;
-    this->hpa = hpaCalculation(altitude);       //hPa hectopascal calculation based on altitude
+    this->hpa = hpaCalculation(altitude);       // hPa hectopascal calculation based on altitude
 
     if (isSensorRegistered(SENSORS::SSCD30)) {
         setSCD30AltitudeOffset(altoffset);
@@ -428,10 +428,12 @@ void Sensors::detectI2COnly(bool enable) {
     i2conly = enable;
 }
 
+/// returns the CanAirIO Sensorslib version
 String Sensors::getLibraryVersion() {
     return String(CSL_VERSION);
 }
 
+/// return the current revision code number
 int16_t Sensors::getLibraryRevision() {
     return CSL_REVISION;
 }
@@ -477,10 +479,9 @@ SensorGroup Sensors::getSensorGroup(SENSORS sensor) {
 
 /**
  * @brief get the sensor registry for retrieve the sensor names
- * @return pointer to the sensor registry
- * @link https://bit.ly/3qVQYYy
+ * @return pointer to the sensor registry.
  * 
- * See the multivariable example: https://bit.ly/2XzZ9yw
+ * See the <a href="https://bit.ly/3qVQYYy">Advanced Multivariable example</a> 
  */
 uint8_t * Sensors::getSensorsRegistered() {
     return sensors_registered;
@@ -489,9 +490,8 @@ uint8_t * Sensors::getSensorsRegistered() {
 /**
  * @brief get the sensor unit status on the registry
  * @return True if the sensor unit is available, false otherwise.
- * @link https://bit.ly/3qVQYYy
  * 
- * See the multivariable example: https://bit.ly/2XzZ9yw
+ * See the <a href="https://bit.ly/3qVQYYy">Advanced Multivariable example</a> 
  */
 bool Sensors::isUnitRegistered(UNIT unit) {
     if (unit == UNIT::NUNIT) return false;
@@ -504,9 +504,8 @@ bool Sensors::isUnitRegistered(UNIT unit) {
 /**
  * @brief get the sensor units registry for retrieve the unit name, unit type and symbol. See getNextUnit()
  * @return pointer to the sensor units registry
- * @link https://bit.ly/3qVQYYy
  * 
- * See the multivariable example: https://bit.ly/2XzZ9yw
+ * See the <a href="https://bit.ly/3qVQYYy">Advanced Multivariable example</a> 
  */
 uint8_t * Sensors::getUnitsRegistered() {
     return units_registered;
@@ -1512,6 +1511,7 @@ void Sensors::bme280Init() {
     sensorRegister(SENSORS::SBME280);
 }
 
+/// Environment BMP280 sensor init
 void Sensors::bmp280Init() {
     sensorAnnounce(SENSORS::SBMP280);
     #ifndef Wire1
@@ -1536,6 +1536,7 @@ void Sensors::bmp280Init() {
     sensorRegister(SENSORS::SBMP280);
 }
 
+/// Bosch BME680 sensor init
 void Sensors::bme680Init() {
     sensorAnnounce(SENSORS::SBME680);
     if (!bme680.begin()) return;
@@ -1547,6 +1548,7 @@ void Sensors::bme680Init() {
     sensorRegister(SENSORS::SBME680);
 }
 
+/// AHTXX sensors init
 void Sensors::aht10Init() {
     sensorAnnounce(SENSORS::SAHTXX);
     aht10 = AHTxx(AHTXX_ADDRESS_X38, AHT1x_SENSOR);
@@ -1558,6 +1560,7 @@ void Sensors::aht10Init() {
     sensorRegister(SENSORS::SAHTXX);
 }
 
+/// Sensirion SCD30 CO2/T/H sensor init
 void Sensors::CO2scd30Init() {
     sensorAnnounce(SENSORS::SSCD30);
     #ifndef Wire1
@@ -1599,6 +1602,7 @@ void Sensors::setSCD30AltitudeOffset(float offset) {
     }
 }
 
+/// Sensirion SCD4X CO2 sensor init
 void Sensors::CO2scd4xInit() {
     sensorAnnounce(SENSORS::SSCD4X);
     float tTemperatureOffset, offsetDifference;
@@ -1649,6 +1653,7 @@ void Sensors::setSCD4xAltitudeOffset(float offset) {
     }
 }
 
+/// Panasonic GCJA5 sensor init
 void Sensors::GCJA5Init() {
     sensorAnnounce(SENSORS::SGCJA5);
     #ifndef Wire1
@@ -1659,6 +1664,7 @@ void Sensors::GCJA5Init() {
     sensorRegister(SENSORS::SGCJA5);
 }
 
+/// DFRobot GAS (CO) sensors init
 void Sensors::DFRobotCOInit() {
   sensorAnnounce(SENSORS::SDFRCO);
   dfrCO = DFRobot_GAS_I2C(&Wire, 0x78); // Be sure that your group of i2c address is 7
@@ -1670,6 +1676,7 @@ void Sensors::DFRobotCOInit() {
   sensorRegister(SENSORS::SDFRCO);
 }
 
+/// DFRobot GAS (NH3) sensors init
 void Sensors::DFRobotNH3Init() {
   sensorAnnounce(SENSORS::SDFRNH3);
   dfrNH3 = DFRobot_GAS_I2C(&Wire, 0x7A); // 0x77 y 0x75 used by bme680. Be sure that your group of i2c address is 7
@@ -1689,6 +1696,7 @@ void Sensors::CO2correctionAlt() {
     DEBUG("-->[SLIB] CO2 compensated\t:", String(CO2Val).c_str());
 }
 
+/// hPa hectopascal calculation based on the altitude. See CO2AltitudeOffset setter
 float Sensors::hpaCalculation(float altitude) {
     DEBUG("-->[SLIB] CO2 altitude offset\t:", String(altitude).c_str());
     float hpa = 1012 - 0.118 * altitude + 0.00000473 * altitude * altitude;            // Cuadratic regresion formula obtained PA (hpa) from high above the sea
@@ -1696,22 +1704,38 @@ float Sensors::hpaCalculation(float altitude) {
     return hpa;
 }
 
+/// utility to notify on the debug output a possible sensor.
 void Sensors::sensorAnnounce(SENSORS sensor) {
     DEBUG("-->[SLIB] attempt enable sensor\t:",getSensorName(sensor).c_str());
 }
 
+/**
+ * @brief register the sensor type.
+ * @param receive SENSORS enum param.
+ * 
+ * Each sensor should be registered and also its units. With that we will able to have
+ * dynamic calls of the sensors and its units on the GUI or implementation.
+*/
 void Sensors::sensorRegister(SENSORS sensor) {
     if (isSensorRegistered(sensor)) return;
     Serial.printf("-->[SLIB] sensor registered\t: %s  \t:D\r\n", getSensorName(sensor).c_str());
     sensors_registered[sensors_registered_count++] = sensor;
 }
 
+/**
+ * @brief register the unit type.
+ * @param receive UNIT enum param.
+ *
+ * Each sensor unit should be registered. For temperature sensors
+ * please use tempRegister() method.
+*/
 void Sensors::unitRegister(UNIT unit) {
     if (isUnitRegistered(unit)) return;
     if (unit == UNIT::NUNIT) return;
     units_registered[units_registered_count++] = unit;
 }
 
+/// reset all library variables (generic sensors units)
 void Sensors::resetAllVariables() {
     pm1 = 0;
     pm25 = 0;
@@ -1739,7 +1763,7 @@ void Sensors::geigerRead(){
 }
 /**
  * @brief Enable Geiger sensor on specific pin
- * @param GPIO pin.
+ * @param gpio number or pin.
 */
 void Sensors::enableGeigerSensor(int gpio){
   sensorAnnounce(SENSORS::SCAJOE);
@@ -1751,11 +1775,19 @@ void Sensors::enableGeigerSensor(int gpio){
   sensorRegister(SENSORS::SCAJOE);
 }
 
+/**
+ * @brief get Geiger count. Tics in the last 60secs
+ * @return CPM
+*/
 uint32_t Sensors::getGeigerCPM(void) {
   if (rad == nullptr) return 0;
   else return rad->getTics();
 }
 
+/**
+ * @brief get Geiger count in uSv/h units
+ * @return CPM * J305 conversion factor
+*/
 float Sensors::getGeigerMicroSievertHour(void) {
   if (rad == nullptr) return 0;
   else return rad->getUSvh();
diff --git a/src/Sensors.hpp b/src/Sensors.hpp
index 6b773a16..9cf8e345 100644
--- a/src/Sensors.hpp
+++ b/src/Sensors.hpp
@@ -84,6 +84,7 @@
 // UART defualt port
 #define SENSOR_COMMS SERIALPORT2
 
+/// Sensors units definitions (symbol/name)
 #define SENSOR_UNITS           \
     X(NUNIT, "NUNIT", "NUNIT") \
     X(PM1, "ug/m3", "PM1")     \
@@ -113,6 +114,7 @@
 typedef enum UNIT : size_t { SENSOR_UNITS } UNIT;
 #undef X
 
+/// sensors types: 1:PM, 2:CO2, 3:ENV
 #define SENSORS_TYPES       \
     X(Auto, "GENERIC", 1)   \
     X(SGCJA5, "GCJA5", 1)   \
@@ -140,14 +142,14 @@ typedef enum UNIT : size_t { SENSOR_UNITS } UNIT;
 typedef enum SENSORS : size_t { SENSORS_TYPES } SENSORS;  // backward compatibility
 #undef X
 
-// MAIN SENSOR TYPE
+/// MAIN SENSOR GROUPS TYPE
 enum class SensorGroup { SENSOR_NONE,
                          SENSOR_PM,
                          SENSOR_CO2,
                          SENSOR_ENV, 
                          SENSOR_RAD  // CAJOE_GEIGER
                          };
-// TEMPERATURE UNIT
+/// TEMPERATURE UNITS
 enum class TEMPUNIT {
     CELSIUS,
     FAHRENHEIT,
@@ -157,81 +159,85 @@ enum class TEMPUNIT {
 typedef void (*errorCbFn)(const char *msg);
 typedef void (*voidCbFn)();
 
+/**
+ * @brief CanAirIO Sensors Manager main class.
+ * @authors \@hpsaturn and CanAir.IO contributers
+*/
 class Sensors {
    public:
-    // SPS30 values. Only for Sensirion SPS30 sensor.
+    /// SPS30 values. Only for Sensirion SPS30 sensor.
     struct sps_values val;
 
-    // Debug mode for increase verbose.
+    /// Debug mode for increase verbose.
     bool devmode;
 
-    // Initial sample time for all sensors
+    /// Initial sample time for all sensors
     int sample_time = 10;
 
-    // temperature offset (for final temp output)
+    /// Temperature offset (for final temp output)
     float toffset = 0.0;
 
-    // Altitud compensation variable
+    /// Altitud compensation variable
     float altoffset = 0.0;
 
-    // Sea level pressure (hPa)
+    /// Sea level pressure (hPa)
     float sealevel = 1013.25;
 
-    // Altitud hpa calculation
+    /// Altitud hpa calculation
     float hpa = 0.0;
 
     /// Sensirion library
     SPS30 sps30;
 
-    // only detect i2c sensors
+    /// only detect i2c sensors flag
     bool i2conly;
 
     /*****************************************
      * I2C sensors:
      ****************************************/
 
-    // AM2320 (Humidity and temperature)
+    /// AM2320 object (Humidity and temperature)
     AM232X am2320;
-    // BME280 (Humidity, Pressure, Altitude and Temperature)
+    /// BME280 object (Humidity, Pressure, Altitude and Temperature)
     Adafruit_BME280 bme280;
-    // BMP280 (Humidity, Pressure, Altitude and Temperature)
+    /// BMP280 object (Humidity, Pressure, Altitude and Temperature)
     Adafruit_BMP280 bmp280;
-    // BME680 (Humidity, Gas, IAQ, Pressure, Altitude and Temperature)
+    /// BME680 object (Humidity, Gas, IAQ, Pressure, Altitude and Temperature)
     Adafruit_BME680 bme680;
-    // AHT10
+    /// AHTXX sensors object
     AHTxx aht10;
-    // SHT31
+    /// SHT31 object (Humidity and temperature)
     Adafruit_SHT31 sht31;
 
     #ifdef DHT11_ENABLED
-    // DHT sensor
+    /// @deprecated DHT sensor variable 
     float dhthumi, dhttemp;
     #endif
-    // Mhz19 sensor
+    /// Mhz19 object sensor
     MHZ19 mhz19;
-    // SCD30 sensor
+    /// SCD30 object sensor
     Adafruit_SCD30 scd30;
-    // CM1106 UART
+    /// CM1106 UART main object sensor
     CM1106_UART *cm1106;
-    // CM1106 UART
+    /// CM1106 UART main variable
     CM1106_sensor cm1106sensor;
-    // CM1106 UART
+    /// CM1106 UART calibration object
     CM1106_ABC abc;
-    // Panasonic SN-GCJA5
+    /// Panasonic SN-GCJA5 object sensor
     SFE_PARTICLE_SENSOR pmGCJA5;
-    // SenseAir S8 CO2 sensor
+    /// SenseAir S8 CO2 object sensor
     S8_UART *s8;
-    // SenseAir S8 CO2 sensor
+    /// SenseAir S8 CO2 object sensor
     S8_sensor s8sensor;
-    // SCD4x sensor
+    /// SCD4x object sensor
     SensirionI2CScd4x scd4x;
-    // IKEA Vindriktn sensor
+    /// IKEA Vindriktn object sensor
     PM1006 *pm1006;
-    // DFRobot gravity NH3 sensor addr 0x74
+    /// DFRobot gravity NH3 object sensor addr 0x74
     DFRobot_GAS_I2C dfrCO;
-    // DFRobot gravity NH3 sensor addr 0x77
+    /// DFRobot gravity NH3 object sensor addr 0x77
     DFRobot_GAS_I2C dfrNH3;
-    // Geiger CAJOE sensor
+    /// Geiger CAJOE object sensor
     GEIGER *rad;
 
     void init(u_int pms_type = 0, int pms_rx = PMS_RX, int pms_tx = PMS_TX);