Merge pull request #96 from tekktrik/feature/custom-characters

Add ability to use custom characters for 7-segment display

Author: FoamyGuy

adafruit_ht16k33/segments.py

@@ -12,7 +12,7 @@
 from adafruit_ht16k33.ht16k33 import HT16K33
 
 try:
-    from typing import Union, List, Tuple
+    from typing import Union, List, Tuple, Optional, Dict
     from busio import I2C
 except ImportError:
     pass
@@ -335,10 +335,17 @@ class Seg7x4(Seg14x4):
 
     POSITIONS = (0, 2, 6, 8)  #  The positions of characters.
 
-    def __init__(self, i2c: I2C, address: int = 0x70, auto_write: bool = True) -> None:
+    def __init__(
+        self,
+        i2c: I2C,
+        address: int = 0x70,
+        auto_write: bool = True,
+        char_dict: Optional[Dict[str, int]] = None,
+    ) -> None:
         super().__init__(i2c, address, auto_write)
         # Use colon for controling two-dots indicator at the center (index 0)
         self._colon = Colon(self)
+        self._chardict = char_dict
 
     def scroll(self, count: int = 1) -> None:
         """Scroll the display by specified number of places.
@@ -370,8 +377,11 @@ def _put(self, char: str, index: int = 0) -> None:
         # pylint: disable=too-many-return-statements
         if not 0 <= index <= 3:
             return
-        char = char.lower()
         index = self.POSITIONS[index]
+        if self._chardict and char in self._chardict:
+            self._set_buffer(index, self._chardict[char])
+            return
+        char = char.lower()
         if char == ".":
             self._set_buffer(index, self._get_buffer(index) | 0b10000000)
             return
@@ -438,11 +448,18 @@ class BigSeg7x4(Seg7x4):
         `show` must be called explicitly.
     """
 
-    def __init__(self, i2c: I2C, address: int = 0x70, auto_write: bool = True) -> None:
+    def __init__(
+        self,
+        i2c: I2C,
+        address: int = 0x70,
+        auto_write: bool = True,
+        char_dict: Optional[Dict[str, int]] = None,
+    ) -> None:
         super().__init__(i2c, address, auto_write)
         # Use colon for controling two-dots indicator at the center (index 0)
         # or the two-dots indicators at the left (index 1)
         self.colon = Colon(self, 2)
+        self._chardict = char_dict
 
     def _setindicator(self, index: int, value: bool) -> None:
         """Set side LEDs (dots)

examples/ht16k33_segments_7x4customchars.py

@@ -0,0 +1,44 @@
+# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
+# SPDX-License-Identifier: MIT
+
+# Basic example of setting digits on a LED segment display.
+# This example and library is meant to work with Adafruit CircuitPython API.
+# Author: Alec Delaney
+# License: Public Domain
+
+# Import all board pins.
+import time
+import board
+import busio
+from adafruit_ht16k33 import segments
+
+# Create the character dictionary
+# You can use the list normally referenced as a starting point
+custom_chars = {}
+typical_list_values = segments.NUMBERS
+typical_list_chars = list("0123456789abcdef-")
+for char, value in zip(typical_list_chars, typical_list_values):
+    custom_chars[char] = value
+
+# Add the custom characters you want
+custom_chars["s"] = 0b01101101
+custom_chars["r"] = 0b01010000
+custom_chars["o"] = 0b00111111
+custom_chars["l"] = 0b00110000
+custom_chars["i"] = 0b00010000
+custom_chars["n"] = 0b01010100
+custom_chars["g"] = 0b01101111
+
+# Create the I2C interface.
+i2c = busio.I2C(board.SCL, board.SDA)
+display = segments.Seg7x4(i2c, char_dict=custom_chars)
+
+# Clear the display.
+display.fill(0)
+
+# Now you can print custom text
+display.print("cool")
+time.sleep(3)
+
+# You can also marquee custom text
+display.marquee("scrolling... ", 0.2)