109 lines
4.1 KiB
ReStructuredText
109 lines
4.1 KiB
ReStructuredText
.. _ls0xx_generic_shield:
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Sharp memory display generic shield
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###################################
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Overview
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********
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This is a generic shield for Sharp memory pixel LCD. It supports
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displays of LS0XX type. These displays have an SPI interface and
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few other pins. Note that the SCS is active high for this display.
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The DISP pin controls whether to display memory
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contents or show all white pixels, this can be connected
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directly to VDD, to always display memory contents or connected
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to a gpio. If devicetree contains ``disp-en-gpios`` then it will be set to
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high during driver initialization. Display blanking apis can be used
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to control it.
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Sharp memory displays require toggling the VCOM signal periodically
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to prevent a DC bias occurring in the panel as mentioned in the `appnote`_
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and `datasheet`_. The DC bias can damage the LCD and reduce the life.
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This signal must be supplied from either serial input (sw) or an external
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signal on the EXTCOMIN pin.
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Currently the driver only supports VCOM toggling using the EXTCOMIN pin
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(EXTMODE pin is connected to VDD).
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When ``extcomin-gpios`` is defined, driver starts a thread which will
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toggle EXTCOMIN at ``extcomin-frequency`` frequency. Higher frequency
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gives better contrast while lower frequency saves power.
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To use a different method of toggling for example pwm, user may not
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define ``extcomin-gpios`` and implement their preferred method in
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application code.
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Pins Assignment of the Generic Sharp memory Display Shield
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==========================================================
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+---------------+---------------------------------------------------------+
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| Pin | Function |
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+===============+=========================================================+
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| SCS | Serial Slave Select |
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+---------------+---------------------------------------------------------+
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| SI | Serial Data Input |
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+---------------+---------------------------------------------------------+
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| SCLK | Serial Clock Input |
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+---------------+---------------------------------------------------------+
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| EXTCOMIN | VCOM Inversion Polarity Input (VCOM can be controlled |
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| | through SW) |
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+---------------+---------------------------------------------------------+
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| DISP | Display ON/OFF switching signal (Can be connected |
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| | directly to VDD) |
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+---------------+---------------------------------------------------------+
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| EXTMODE | COM Inversion Selection |
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+---------------+---------------------------------------------------------+
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Current supported displays
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==========================
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Following displays are supported but shield only exists
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for LS013B7DH03. Other shields can be added by using the LS013B7DH03 as
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a reference and changing the width, height, etc configurations.
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LS012B7DD01
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LS012B7DD06
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LS013B7DH03
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LS013B7DH05
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LS013B7DH06
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LS027B7DH01A
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LS032B7DD02
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LS044Q7DH01
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+----------------------+------------------------------+
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| Display | Shield Designation |
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| | |
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+======================+==============================+
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| LS013B7DH03 | ls013b7dh03 |
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+----------------------+------------------------------+
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Requirements
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************
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This shield can only be used with a board that provides a configuration
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for Arduino connectors and defines node aliases for SPI and GPIO interfaces
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(see :ref:`shields` for more details).
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Programming
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***********
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Set ``-DSHIELD=ls013b7dh03`` when you invoke ``west build``. For example:
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.. zephyr-app-commands::
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:zephyr-app: samples/subsys/display/lvgl
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:board: nrf52840dk_nrf52840
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:shield: ls013b7dh03
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:goals: build
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References
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**********
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.. target-notes::
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.. _appnote:
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https://www.sharpsma.com/documents/1468207/1485747/Memory+LCD+Theory%2C+Programming%2C+and+Interfaces
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.. _datasheet:
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https://www.mouser.com/datasheet/2/365/LS013B7DH03%20SPEC_SMA-224806.pdf
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