HT1621 driver

README.rst

@@ -8,7 +8,7 @@ luma.lcd **|**
 
 Luma.LCD
 ========
-**PCD8544, ST7735 Display Drivers**
+**PCD8544, ST7735, HT1621 Display Drivers**
 
 .. image:: https://travis-ci.org/rm-hull/luma.lcd.svg?branch=master
    :target: https://travis-ci.org/rm-hull/luma.lcd
@@ -28,24 +28,26 @@ Luma.LCD
 
 .. image:: https://img.shields.io/maintenance/yes/2017.svg?maxAge=2592000
 
-Python library interfacing LCD displays with the PCD8544 or ST7735 driver using
-SPI on the Raspberry Pi and other linux-based single-board computers - it
-provides a Pillow-compatible drawing canvas, and other functionality to
-support:
+Python library interfacing LCD displays with the PCD8544, ST7735 and HT1621
+driver using SPI on the Raspberry Pi and other linux-based single-board
+computers - it provides a Pillow-compatible drawing canvas, and other
+functionality to support:
 
 * scrolling/panning capability,
 * terminal-style printing,
 * state management,
 * color/greyscale (where supported),
 * dithering to monochrome
 
-Both types of modules can be picked up on ebay with a breakout board
-for a few pounds.
+All modules can be picked up on ebay with a breakout board for a few pounds.
 
 .. image:: https://raw.github.com/rm-hull/luma.lcd/master/doc/images/pcd8544.png
 
 .. image:: https://raw.github.com/rm-hull/luma.lcd/master/doc/images/st7735.jpg
 
+.. image:: https://raw.github.com/rm-hull/luma.lcd/master/doc/images/ht1621.jpg
+
+
 Documentation
 -------------
 Full documentation with installation instructions and examples can be found on

doc/install.rst

@@ -74,49 +74,58 @@ Raspberry Pi, up to and including the Raspberry Pi 3 B.
 
 PCD8544
 """""""
-========== ====== ============ ======== ==============
-LCD Pin    Name   Remarks      RPi Pin  RPi Function
-========== ====== ============ ======== ==============
-1          RST    Reset        P01-18   GPIO 24 
-2          CE     Chip Enable  P01-24   GPIO 8 (CE0)
-3          DC     Data/Command P01-16   GPIO 23
-4          DIN    Data In      P01-19   GPIO 10 (MOSI)
-5          CLK    Clock        P01-23   GPIO 11 (SCLK)
-6          VCC    +3.3V Power  P01-01   3V3
-7          LIGHT  Backlight    P01-12   GPIO 18 (PCM_CLK)
-8          GND    Ground       P01-06   GND
-========== ====== ============ ======== ==============
+======== ============ ======== ==============
+LCD Pin  Remarks      RPi Pin  RPi Function
+======== ============ ======== ==============
+RST      Reset        P01-18   GPIO 24 
+CE       Chip Enable  P01-24   GPIO 8 (CE0)
+DC       Data/Command P01-16   GPIO 23
+DIN      Data In      P01-19   GPIO 10 (MOSI)
+CLK      Clock        P01-23   GPIO 11 (SCLK)
+VCC      +3.3V Power  P01-01   3V3
+LIGHT    Backlight    P01-12   GPIO 18 (PCM_CLK)
+GND      Ground       P01-06   GND
+======== ============ ======== ==============
 
 ST7735
 """"""
-========== ======= ================= ======== ==============
-LCD Pin    Name    Remarks           RPi Pin  RPi Function
-========== ======= ================= ======== ==============
-1          GND     Ground            P01-06   GND
-2          VCC     +3.3V Power       P01-01   3V3
-3          NC      Not connected     -        -
-4          NC      Not connected     -        -
-5          NC      Not connected     -        -
-6          RESET   Reset             P01-18   GPIO 24
-7          A0      Data/command      P01-16   GPIO 23
-8          SDA     SPI data          P01-19   GPIO 10 (MOSI)
-9          SCK     SPI clock         P01-23   GPIO 11 (SCLK)
-10         CS      SPI chip select   P01-24   GPIO 8 (CE0)
-11         SD-SCK  SD serial clock   -        -
-12         SD-MISO SD data in        -        -
-13         SD-MOSI SD data out       -        -
-14         SD-CS   SD chip select    -        -
-15         LED+    Backlight control P01-12   GPIO 18 (PCM_CLK)
-16         LED-    Backlight ground  P01-06   GND
-========== ======= ================= ======== ==============
+Depending on the board you bought, there may be different names for the same 
+pins, as detailed below.
+============= ================= ======== ==============
+LCD Pin       Remarks           RPi Pin  RPi Function
+============= ================= ======== ==============
+GND           Ground            P01-06   GND
+VCC           +3.3V Power       P01-01   3V3
+RESET or RST  Reset             P01-18   GPIO 24
+A0 or D/C     Data/command      P01-16   GPIO 23
+SDA or DIN    SPI data          P01-19   GPIO 10 (MOSI)
+SCK or CLK    SPI clock         P01-23   GPIO 11 (SCLK)
+CS            SPI chip select   P01-24   GPIO 8 (CE0)
+LED+ or BL    Backlight control P01-12   GPIO 18 (PCM_CLK)
+LED-          Backlight ground  P01-06   GND
+============= ================= ======== ==============
+
+HT1621
+""""""
+============= ================= ======== ==============
+LCD Pin       Remarks           RPi Pin  RPi Function
+============= ================= ======== ==============
+GND           Ground            P01-06   GND
+VCC           +3.3V Power       P01-01   3V3
+DAT           SPI data          P01-19   GPIO 10 (MOSI)
+WR            SPI clock         P01-23   GPIO 11 (SCLK)
+CS            SPI chip select   P01-24   GPIO 8 (CE0)
+LED           Backlight control P01-12   GPIO 18 (PCM_CLK)
+============= ================= ======== ==============
+
 
 Installing from PyPI
 ^^^^^^^^^^^^^^^^^^^^
 Install the dependencies for library first with::
 
   $ sudo usermod -a -G spi,gpio pi
   $ sudo apt-get install python-dev python-pip
-  $ sudo -i pip install --upgrade pip
+  $ sudo -i pip install --upgrade pip setuptools
   $ sudo apt-get purge python-pip
 
 .. warning:: The default pip bundled with apt on Raspbian is really old, and can 
@@ -127,7 +136,7 @@ Install the dependencies for library first with::
       pip 9.0.1 from /usr/local/lib/python2.7/dist-packages (python 2.7)
 
 Proceed to install latest version of the library directly from
-`PyPI <https://pypi.python.org/pypi?:action=display&name=luma.led_matrix>`_::
+`PyPI <https://pypi.python.org/pypi?:action=display&name=luma.lcd>`_::
 
   $ sudo -H pip install --upgrade luma.lcd
 

doc/intro.rst

@@ -1,6 +1,6 @@
 Introduction
 ------------
-Interfacing small LCD displays with the PCD8544 and ST7735 driver in Python
+Interfacing small LCD displays with the PCD8544, ST7735 and HT1621 driver in Python
 using SPI on the Raspberry Pi and other linux-based single-board computers: the
 library provides a Pillow-compatible drawing canvas, and other functionality to
 support:
@@ -26,12 +26,18 @@ colors) with a switchable backlight:
 
 .. image:: images/st7735.jpg
 
+The HT1621 display (as purchased) supports six 7-segment characters with a 
+switchable backlight:
+
+.. image:: images/ht1621.jpg
+
 .. seealso::
    Further technical information for the specific device can be found in the
    datasheet below: 
 
    - :download:`PCD8544 <tech-spec/PCD8544.pdf>`
    - :download:`ST7735 <tech-spec/ST7735.pdf>`
+   - :download:`HT1621 <tech-spec/HT1621.pdf>`
 
 As well as display drivers for the physical device, there are emulators that
 run in real-time (with pygame) and others that can take screenshots, or

doc/python-usage.rst

@@ -1,5 +1,8 @@
 Python usage
 ------------
+
+Pixel Drivers
+^^^^^^^^^^^^^
 The PCD8544 is driven with python using the implementation in the
 :py:class:`luma.lcd.device.pcd8544` class. Likewise, to drive the ST7735, use
 the :py:class:`luma.lcd.device.st7735` class. Usage is very simple if you have
@@ -43,7 +46,7 @@ flushed to the device's display memory and the :mod:`PIL.ImageDraw` object is
 garbage collected.
 
 Color Model
-^^^^^^^^^^^
+"""""""""""
 Any of the standard :py:mod:`PIL.ImageColor` color formats may be used, but
 since the PCD8544 LCD is monochrome, only the HTML color names
 :py:const:`"black"` and :py:const:`"white"` values should really be used; in
@@ -61,7 +64,7 @@ Note that there is no such limitation for the ST7735 device which supports 262K
 colour RGB images, whereby 24-bit RGB images are downscaled to 18-bit RGB.
 
 Landscape / Portrait Orientation
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+""""""""""""""""""""""""""""""""
 By default the PCD8544 and ST7735 displays will both be oriented in landscape
 mode (84x48 and 160x128 pixels respectively). Should you have an application
 that requires the display to be mounted in a portrait aspect, then add a
@@ -87,6 +90,48 @@ rotate 90° clockwise, 2 is 180° rotation and 3 represents 270° rotation.
 The :py:attr:`device.size`, :py:attr:`device.width` and :py:attr:`device.height`
 properties reflect the rotated dimensions rather than the physical dimensions.
 
+Seven-Segment Drivers
+^^^^^^^^^^^^^^^^^^^^^
+The HT1621 is driven with the :py:class:`luma,lcd.device.ht1621` class, but is 
+not accessed directly: it should be wrapped with the :py:class:`luma.core.virtual.sevensegment`
+wrapper, as follows:
+
+.. code:: python
+
+   from luma.core.virtual import sevensegment
+   from luma.lcd.device import ht1621
+
+   device = ht1621()
+   seg = sevensegment(device)
+   
+   
+The **seg** instance now has a :py:attr:`~luma.led_matrix.virtual.sevensegment.text` 
+property which may be assigned, and when it does will update all digits
+according to the limited alphabet the 7-segment displays support. For example,
+assuming there are 2 cascaded modules, we have 16 character available, and so
+can write:
+
+.. code:: python
+
+   seg.text = "HELLO"
+
+Rather than updating the whole display buffer, it is possible to update
+'slices', as per the below example:
+
+.. code:: python
+
+   seg.text[0:5] = "BYE"
+
+This replaces ``HELLO`` in the previous example, replacing it with ``BYE``.
+The usual python idioms for slicing (inserting / replacing / deleteing) can be
+used here, but note if inserted text exceeds the underlying buffer size, a
+:py:exc:`ValueError` is raised.
+
+Floating point numbers (or text with '.') are handled slightly differently - the
+decimal-place is fused in place on the character immediately preceding it. This
+means that it is technically possible to get more characters displayed than the
+buffer allows, but only because dots are folded into their host character.
+
 Backlight Control
 ^^^^^^^^^^^^^^^^^
 These displays typically require a backlight to illuminate the liquid crystal
@@ -95,65 +140,5 @@ be specified to control the backlight through software.
 
 Examples
 ^^^^^^^^
-After installing the library, download the `luma.examples
-<https://github.com/rm-hull/luma.examples>`_ directory and try running the
-following examples:
-
-=============== ========================================================
-Example         Description
-=============== ========================================================
-3d_box.py       Rotating 3D box wireframe & color dithering
-bounce.py       Display a bouncing ball animation and frames per second
-carousel.py     Showcase viewport and hotspot functionality
-clock.py        An analog clockface with date & time
-colors.py       Color rendering demo
-crawl.py        A vertical scrolling demo, which should be familiar
-demo.py         Use misc draw commands to create a simple image
-game_of_life.py Conway's game of life
-grayscale.py    Greyscale rendering demo
-invaders.py     Space Invaders demo
-maze.py         Maze generator
-perfloop.py     Simple benchmarking utility to measure performance
-pi_logo.py      Display the Raspberry Pi logo (loads image as .png)
-savepoint.py    Example of savepoint/restore functionality
-starfield.py    3D starfield simulation
-sys_info.py     Display basic system information
-terminal.py     Simple println capabilities
-tv_snow.py      Example image-blitting
-welcome.py      Unicode font rendering & scrolling
-=============== ========================================================
-
-See the README in that project for further information on how to run the demos.
-
-Emulators
-^^^^^^^^^
-There are various display emulators available for running code against, for
-debugging and screen capture functionality:
-
-* The :py:class:`luma.emulator.device.capture` device will persist a numbered
-  PNG file to disk every time its :py:meth:`~luma.emulator.device.capture.display`
-  method is called.
-
-* The :py:class:`luma.emulator.device.gifanim` device will record every image
-  when its :py:meth:`~luma.emulator.device.gifanim.display` method is called,
-  and on program exit (or Ctrl-C), will assemble the images into an animated GIF.
-
-* The :py:class:`luma.emulator.device.pygame` device uses the :py:mod:`pygame`
-  library to render the displayed image to a pygame display surface.
-
-Invoke the demos with::
-
-  $ python examples/clock.py -d capture
-
-or::
-
-  $ python examples/clock.py -d pygame
-  
-.. note::
-   *Pygame* is required to use any of the emulated devices, but it is **NOT**
-   installed as a dependency by default, and so must be manually installed
-   before using any of these emulation devices (e.g. ``pip install pygame``).
-   See the install instructions in `luma.emulator  <http://github.com/rm-hull/luma.emulator>`_
-   for further details.
-
-
+After installing the library, head over to the `luma.examples <https://github.com/rm-hull/luma.examples>`_ 
+repository. Details of how to run the examples is shown in the example repo's README.

luma/lcd/const.py

@@ -11,3 +11,8 @@ class pcd8544(object):
 class st7735(object):
     DISPLAYON = 0x29
     DISPLAYOFF = 0x28
+
+
+class ht1621(object):
+    DISPLAYON = 0x06
+    DISPLAYOFF = 0x04