set all the MCP23008 gpio bits at once to speed up I2C

Author: dhalbert

.pre-commit-config.yaml

@@ -4,21 +4,21 @@
 
 repos:
 -   repo: https://github.com/python/black
-    rev: 20.8b1
+    rev: 23.3.0
     hooks:
     - id: black
 -   repo: https://github.com/fsfe/reuse-tool
-    rev: v0.12.1
+    rev: v1.1.1
     hooks:
     - id: reuse
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v2.3.0
+    rev: v4.4.0
     hooks:
     -   id: check-yaml
     -   id: end-of-file-fixer
     -   id: trailing-whitespace
 -   repo: https://github.com/pycqa/pylint
-    rev: v2.11.1
+    rev: v3.3.1
     hooks:
     -   id: pylint
         name: pylint (library code)

.pylintrc

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
+# SPDX-FileCopyrightText: 2017 Scott Shawcroft, written for Adafruit Industries
 #
 # SPDX-License-Identifier: Unlicense
 
@@ -9,11 +9,11 @@
 # run arbitrary code
 extension-pkg-whitelist=
 
-# Add files or directories to the blacklist. They should be base names, not
+# Add files or directories to the ignore-list. They should be base names, not
 # paths.
 ignore=CVS
 
-# Add files or directories matching the regex patterns to the blacklist. The
+# Add files or directories matching the regex patterns to the ignore-list. The
 # regex matches against base names, not paths.
 ignore-patterns=
 
@@ -26,7 +26,7 @@ jobs=1
 
 # List of plugins (as comma separated values of python modules names) to load,
 # usually to register additional checkers.
-load-plugins=
+load-plugins=pylint.extensions.no_self_use
 
 # Pickle collected data for later comparisons.
 persistent=yes
@@ -54,8 +54,8 @@ confidence=
 # --enable=similarities". If you want to run only the classes checker, but have
 # no Warning level messages displayed, use"--disable=all --enable=classes
 # --disable=W"
-# disable=import-error,print-statement,parameter-unpacking,unpacking-in-except,old-raise-syntax,backtick,long-suffix,old-ne-operator,old-octal-literal,import-star-module-level,raw-checker-failed,bad-inline-option,locally-disabled,locally-enabled,file-ignored,suppressed-message,useless-suppression,deprecated-pragma,apply-builtin,basestring-builtin,buffer-builtin,cmp-builtin,coerce-builtin,execfile-builtin,file-builtin,long-builtin,raw_input-builtin,reduce-builtin,standarderror-builtin,unicode-builtin,xrange-builtin,coerce-method,delslice-method,getslice-method,setslice-method,no-absolute-import,old-division,dict-iter-method,dict-view-method,next-method-called,metaclass-assignment,indexing-exception,raising-string,reload-builtin,oct-method,hex-method,nonzero-method,cmp-method,input-builtin,round-builtin,intern-builtin,unichr-builtin,map-builtin-not-iterating,zip-builtin-not-iterating,range-builtin-not-iterating,filter-builtin-not-iterating,using-cmp-argument,eq-without-hash,div-method,idiv-method,rdiv-method,exception-message-attribute,invalid-str-codec,sys-max-int,bad-python3-import,deprecated-string-function,deprecated-str-translate-call
-disable=print-statement,parameter-unpacking,unpacking-in-except,old-raise-syntax,backtick,long-suffix,old-ne-operator,old-octal-literal,import-star-module-level,raw-checker-failed,bad-inline-option,locally-disabled,locally-enabled,file-ignored,suppressed-message,useless-suppression,deprecated-pragma,apply-builtin,basestring-builtin,buffer-builtin,cmp-builtin,coerce-builtin,execfile-builtin,file-builtin,long-builtin,raw_input-builtin,reduce-builtin,standarderror-builtin,unicode-builtin,xrange-builtin,coerce-method,delslice-method,getslice-method,setslice-method,no-absolute-import,old-division,dict-iter-method,dict-view-method,next-method-called,metaclass-assignment,indexing-exception,raising-string,reload-builtin,oct-method,hex-method,nonzero-method,cmp-method,input-builtin,round-builtin,intern-builtin,unichr-builtin,map-builtin-not-iterating,zip-builtin-not-iterating,range-builtin-not-iterating,filter-builtin-not-iterating,using-cmp-argument,eq-without-hash,div-method,idiv-method,rdiv-method,exception-message-attribute,invalid-str-codec,sys-max-int,bad-python3-import,deprecated-string-function,deprecated-str-translate-call,import-error,bad-continuation,unspecified-encoding
+# disable=import-error,raw-checker-failed,bad-inline-option,locally-disabled,file-ignored,suppressed-message,useless-suppression,deprecated-pragma,deprecated-str-translate-call
+disable=raw-checker-failed,bad-inline-option,locally-disabled,file-ignored,suppressed-message,useless-suppression,deprecated-pragma,import-error,pointless-string-statement,unspecified-encoding
 
 # Enable the message, report, category or checker with the given id(s). You can
 # either give multiple identifier separated by comma (,) or put this option
@@ -225,12 +225,6 @@ max-line-length=100
 # Maximum number of lines in a module
 max-module-lines=1000
 
-# List of optional constructs for which whitespace checking is disabled. `dict-
-# separator` is used to allow tabulation in dicts, etc.: {1  : 1,\n222: 2}.
-# `trailing-comma` allows a space between comma and closing bracket: (a, ).
-# `empty-line` allows space-only lines.
-no-space-check=trailing-comma,dict-separator
-
 # Allow the body of a class to be on the same line as the declaration if body
 # contains single statement.
 single-line-class-stmt=no
@@ -252,53 +246,34 @@ ignore-docstrings=yes
 ignore-imports=yes
 
 # Minimum lines number of a similarity.
-min-similarity-lines=4
+min-similarity-lines=12
 
 
 [BASIC]
 
-# Naming hint for argument names
-argument-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
-
 # Regular expression matching correct argument names
 argument-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
 
-# Naming hint for attribute names
-attr-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
-
 # Regular expression matching correct attribute names
 attr-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
 
 # Bad variable names which should always be refused, separated by a comma
 bad-names=foo,bar,baz,toto,tutu,tata
 
-# Naming hint for class attribute names
-class-attribute-name-hint=([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$
-
 # Regular expression matching correct class attribute names
 class-attribute-rgx=([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$
 
-# Naming hint for class names
-# class-name-hint=[A-Z_][a-zA-Z0-9]+$
-class-name-hint=[A-Z_][a-zA-Z0-9_]+$
-
 # Regular expression matching correct class names
 # class-rgx=[A-Z_][a-zA-Z0-9]+$
 class-rgx=[A-Z_][a-zA-Z0-9_]+$
 
-# Naming hint for constant names
-const-name-hint=(([A-Z_][A-Z0-9_]*)|(__.*__))$
-
 # Regular expression matching correct constant names
 const-rgx=(([A-Z_][A-Z0-9_]*)|(__.*__))$
 
 # Minimum line length for functions/classes that require docstrings, shorter
 # ones are exempt.
 docstring-min-length=-1
 
-# Naming hint for function names
-function-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
-
 # Regular expression matching correct function names
 function-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
 
@@ -309,21 +284,12 @@ good-names=r,g,b,w,i,j,k,n,x,y,z,ex,ok,Run,_
 # Include a hint for the correct naming format with invalid-name
 include-naming-hint=no
 
-# Naming hint for inline iteration names
-inlinevar-name-hint=[A-Za-z_][A-Za-z0-9_]*$
-
 # Regular expression matching correct inline iteration names
 inlinevar-rgx=[A-Za-z_][A-Za-z0-9_]*$
 
-# Naming hint for method names
-method-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
-
 # Regular expression matching correct method names
 method-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
 
-# Naming hint for module names
-module-name-hint=(([a-z_][a-z0-9_]*)|([A-Z][a-zA-Z0-9]+))$
-
 # Regular expression matching correct module names
 module-rgx=(([a-z_][a-z0-9_]*)|([A-Z][a-zA-Z0-9]+))$
 
@@ -339,9 +305,6 @@ no-docstring-rgx=^_
 # to this list to register other decorators that produce valid properties.
 property-classes=abc.abstractproperty
 
-# Naming hint for variable names
-variable-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
-
 # Regular expression matching correct variable names
 variable-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
 
@@ -398,7 +361,7 @@ valid-metaclass-classmethod-first-arg=mcs
 [DESIGN]
 
 # Maximum number of arguments for function / method
-max-args=5
+max-args=13
 
 # Maximum number of attributes for a class (see R0902).
 # max-attributes=7
@@ -433,4 +396,4 @@ min-public-methods=1
 
 # Exceptions that will emit a warning when being caught. Defaults to
 # "Exception"
-overgeneral-exceptions=Exception
+overgeneral-exceptions=builtins.Exception

adafruit_character_lcd/character_lcd.py

@@ -96,7 +96,7 @@ def _map(xval, in_min, in_max, out_min, out_max):
     return ret
 
 
-# pylint: disable-msg=too-many-instance-attributes
+# pylint: disable=too-many-instance-attributes
 class Character_LCD:
     """Base class for character LCD.
 
@@ -114,9 +114,8 @@ class Character_LCD:
     LEFT_TO_RIGHT = const(0)
     RIGHT_TO_LEFT = const(1)
 
-    # pylint: disable-msg=too-many-arguments
+    # pylint: disable=too-many-positional-arguments,invalid-name
     def __init__(self, rs, en, d4, d5, d6, d7, columns, lines):
-
         self.columns = columns
         self.lines = lines
         #  save pin numbers
@@ -148,9 +147,9 @@ def __init__(self, rs, en, d4, d5, d6, d7, columns, lines):
         self._write8(_LCD_ENTRYMODESET | self.displaymode)
         self.clear()
 
-        self._message = None
-        self._enable = None
-        self._direction = None
+        self._message = ""
+        self._backlight_on = False
+        self._direction = self.LEFT_TO_RIGHT
         # track row and column used in cursor_position
         # initialize to 0,0
         self.row = 0
@@ -484,6 +483,7 @@ def create_char(self, location, pattern):
             self._write8(pattern[i], char_mode=True)
 
     def _write8(self, value, char_mode=False):
+        print(f"bit-by-bit: {char_mode=}, {value=:x}")
         # Sends 8b ``value`` in ``char_mode``.
         # :param value: bytes
         # :param char_mode: character/data mode selector. False (default) for
@@ -520,7 +520,7 @@ def _pulse_enable(self):
 # pylint: enable-msg=too-many-instance-attributes
 
 
-# pylint: disable-msg=too-many-instance-attributes
+# pylint: disable=too-many-instance-attributes
 class Character_LCD_Mono(Character_LCD):
     """Interfaces with monochromatic character LCDs.
 
@@ -539,7 +539,7 @@ class Character_LCD_Mono(Character_LCD):
 
     """
 
-    # pylint: disable-msg=too-many-arguments
+    # pylint: disable=too-many-positional-arguments
     def __init__(
         self,
         rs,
@@ -553,7 +553,6 @@ def __init__(
         backlight_pin=None,
         backlight_inverted=False,
     ):
-
         # Backlight pin and inversion
         self.backlight_pin = backlight_pin
         self.backlight_inverted = backlight_inverted
@@ -591,15 +590,12 @@ def backlight(self):
             time.sleep(5)
 
         """
-        return self._enable
+        return self._backlight_on
 
     @backlight.setter
     def backlight(self, enable):
-        self._enable = enable
-        if enable:
-            self.backlight_pin.value = not self.backlight_inverted
-        else:
-            self.backlight_pin.value = self.backlight_inverted
+        self._backlight_on = enable
+        self.backlight_pin.value = enable ^ self.backlight_inverted
 
 
 class Character_LCD_RGB(Character_LCD):
@@ -621,7 +617,7 @@ class Character_LCD_RGB(Character_LCD):
 
     """
 
-    # pylint: disable-msg=too-many-arguments
+    # pylint: disable=too-many-positional-arguments,invalid-name
     def __init__(
         self,
         rs,
@@ -637,7 +633,6 @@ def __init__(
         blue,
         read_write=None,
     ):
-
         # Define read_write (rw) pin
         self.read_write = read_write
 

adafruit_character_lcd/character_lcd_i2c.py

@@ -28,6 +28,8 @@
 
 """
 
+import time
+
 from adafruit_mcp230xx.mcp23008 import MCP23008
 from adafruit_character_lcd.character_lcd import Character_LCD_Mono
 
@@ -36,7 +38,7 @@
 
 
 class Character_LCD_I2C(Character_LCD_Mono):
-    # pylint: disable=too-few-public-methods, too-many-arguments
+    # pylint: disable=too-few-public-methods
     """Character LCD connected to I2C/SPI backpack using its I2C connection.
     This is a subclass of `Character_LCD_Mono` and implements all of the
     same functions and functionality.
@@ -52,25 +54,59 @@ class Character_LCD_I2C(Character_LCD_Mono):
         lcd = Character_LCD_I2C(i2c, 16, 2)
     """
 
+    # pylint: disable=too-many-positional-arguments
     def __init__(self, i2c, columns, lines, address=None, backlight_inverted=False):
         """Initialize character LCD connected to backpack using I2C connection
         on the specified I2C bus with the specified number of columns and
         lines on the display. Optionally specify if backlight is inverted.
         """
 
         if address:
-            mcp = MCP23008(i2c, address=address)
+            self.mcp = MCP23008(i2c, address=address)
         else:
-            mcp = MCP23008(i2c)
+            self.mcp = MCP23008(i2c)
         super().__init__(
-            mcp.get_pin(1),
-            mcp.get_pin(2),
-            mcp.get_pin(3),
-            mcp.get_pin(4),
-            mcp.get_pin(5),
-            mcp.get_pin(6),
+            self.mcp.get_pin(1),  # reset
+            self.mcp.get_pin(2),  # enable
+            self.mcp.get_pin(3),  # data line 4
+            self.mcp.get_pin(4),  # data line 5
+            self.mcp.get_pin(5),  # data line 6
+            self.mcp.get_pin(6),  # data line 7
             columns,
             lines,
-            backlight_pin=mcp.get_pin(7),
+            backlight_pin=self.mcp.get_pin(7),
             backlight_inverted=backlight_inverted,
         )
+
+    def _write8(self, value, char_mode=False):
+        # Sends 8b ``value`` in ``char_mode``.
+        # :param value: bytes
+        # :param char_mode: character/data mode selector. False (default) for
+        # data only, True for character bits.
+        #  one ms delay to prevent writing too quickly.
+        time.sleep(0.001)
+
+        # bits are, MSB (7) to LSB (0)
+        # backlight:   bit 7
+        # data line 7: bit 6
+        # data line 6: bit 5
+        # data line 5: bit 4
+        # data line 4: bit 3
+        # enable:      bit 2
+        # reset:       bit 1
+        # (unused):    bit 0
+
+        reset_bit = int(char_mode) << 1
+        backlight_bit = int(self.backlight ^ self.backlight_inverted) << 7
+
+        # Write char_mode and upper 4 bits of data, shifted to the correct position.
+        self.mcp.gpio = reset_bit | backlight_bit | ((value & 0xF0) >> 1)
+
+        #  do command
+        self._pulse_enable()
+
+        # Write char_mode and lower 4 bits of data, shifted to the correct position.
+        self.mcp.gpio = reset_bit | backlight_bit | ((value & 0x0F) << 3)
+
+        # do command
+        self._pulse_enable()