Class: Denko::Display::ST7565

Inherits:
Object
  • Object
show all
Includes:
Behaviors::Lifecycle, SPICommon
Defined in:
lib/denko/display/st7565.rb

Constant Summary collapse

COLUMNS = 
128
ROWS = 
64
RESET =

Overall commands

0b11100010
DISPLAY_ON = 
0b10101111
DISPLAY_OFF = 
0b10101110
ALL_POINTS_OFF = 
0b10100100
ALL_POINTS_ON = 
0b10100100
STATIC_INDICATOR_OFF = 
0b10101100
STATIC_INDICATOR_ON = 
0b10101101
POWER_CONTROL =

Overall votage commands

0b00101000
LCD_BIAS_1_7 = 
0b10100011
VOLUME = 
0b10000001
VALID_VOLUMES = 
(0..63).to_a
RESISTOR_RATIO =

Control voltage regulator circuit. Values 0-7 are OR’ed into last 3 bits. 5 seems to work best for non-inverted mode, and 6 for inverted.

0b00100000
VALID_RESISTOR_RATIOS = 
(0..7).to_a
RMW_WRITE =

Addressing and writing to display RAM. Always in write mode. Called Read-Modify-Write and END in datasheet.

0b11100000
RMW_END = 
0b11101110
PASET =

Set page and column to start on before writing data. Page and column nibbles are OR’ed into lower 4 bits.

0b10110000
CASET_UPPER = 
0b00010000
CASET_LOWER = 
0b00000000
COL_NORMAL =

Control X and Y mirroring, so the display can be reflected in either axis, or rotated 180 degrees, in hardware.

How RAM columns map to pixels. Called ADC in datasheet.

0b10100000
COL_REVERSE = 
0b10100001
PAGE_NORMAL =

How RAM pages map to pixels. Called Common Output Mode in datasheet.

0b11000000
PAGE_REVERSE = 
0b11001000
COL_REVERSE_COL_START =

RAM has 132 columns. Need to start at index 4 when columns get reversed.

4
INVERT_OFF =

Control display inversion. White on black is OFF. Black on white ON.

0b10100110
INVERT_ON = 
0b10100111

Constants included from Behaviors::Lifecycle

Behaviors::Lifecycle::CALLBACK_METHODS

Instance Attribute Summary

Attributes included from SPI::Peripheral

#spi_bit_order, #spi_frequency, #spi_mode

Attributes included from Behaviors::State

#state

Attributes included from Behaviors::Component

#board, #params

Attributes included from Behaviors::MultiPin

#pin, #pins, #proxies

Instance Method Summary collapse

Methods included from SPICommon

#command, #data, #initialize_pins, #transfer_limit

Methods included from PixelCommon

#canvas, #colors, #columns, #draw, #get_partial_buffer, #p_max, #p_min, #refresh, #rows, #x_max, #x_min, #y_max, #y_min

Methods included from SPI::Peripheral

#ensure_byte_array, #initialize_pins, #proxy_pin, #spi_listen, #spi_read, #spi_stop, #spi_transfer, #spi_write, #update

Methods included from Behaviors::Lifecycle

included

Methods included from Behaviors::Callbacks

#add_callback, #callbacks, #pre_callback_filter, #remove_callback, #update

Methods included from Behaviors::State

#update_state

Methods included from Behaviors::BusPeripheral

#atomically

Methods included from Behaviors::Component

#initialize, #micro_delay

Methods included from Behaviors::MultiPin

#convert_pins, #proxy_pin, #proxy_states, #require_pin, #require_pins

Instance Method Details

#draw_partial(buffer, x_start, x_finish, p_start, p_finish, color = 1) ⇒ Object 



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# File 'lib/denko/display/st7565.rb', line 144

def draw_partial(buffer, x_start, x_finish, p_start, p_finish, color=1)
  x = x_start + x_ram_offset
  x_lower4 = (x & 0b00001111)
  x_upper4 = (x & 0b11110000) >> 4

  (p_start..p_finish).each do |page|
    command [RMW_WRITE]
    # Set start page and column.
    command [PASET | page, CASET_LOWER | x_lower4, CASET_UPPER | x_upper4]

    # Get needed bytes for this page only.
    src_start       = (columns * page) + x_start
    src_end         = (columns * page) + x_finish
    partial_buffer  = buffer[src_start..src_end]

    # Send in chunks up to maximum transfer size.
    partial_buffer.each_slice(transfer_limit) { |slice| data(slice) }
    command [RMW_END]
  end
end

#invert ⇒ Object 



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# File 'lib/denko/display/st7565.rb', line 104

def invert
  @inverted ||= false
  if @inverted
    command [INVERT_OFF]
    self.resistor_ratio = 5
  else
    command [INVERT_ON]
    self.resistor_ratio = 6
  end
  @inverted = !@inverted
end

#reflect_x ⇒ Object 



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# File 'lib/denko/display/st7565.rb', line 81

def reflect_x
  @reflected_x ||= false
  @reflected_x ? command([COL_NORMAL]) : command([COL_REVERSE])
  @reflected_x = !@reflected_x
  @x_ram_offset = @reflected_x ? COL_REVERSE_COL_START : 0
end

#reflect_y ⇒ Object 



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# File 'lib/denko/display/st7565.rb', line 88

def reflect_y
  @reflected_y ||= false
  @reflected_y ? command([PAGE_NORMAL]) : command([PAGE_REVERSE])
  @reflected_y = !@reflected_y
end

#resistor_ratio=(ratio) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/denko/display/st7565.rb', line 43

def resistor_ratio=(ratio)
  raise ArgumentError, "invalid resistor ratio #{ratio}" unless VALID_RESISTOR_RATIOS.include? ratio
  command [RESISTOR_RATIO | ratio]
end

#rotate ⇒ Object 



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# File 'lib/denko/display/st7565.rb', line 94

def rotate
  reflect_x
  reflect_y
end

#slp ⇒ Object 



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# File 'lib/denko/display/st7565.rb', line 23

def slp
  command [STATIC_INDICATOR_OFF, 0b00, DISPLAY_OFF, ALL_POINTS_ON]
end

#standby ⇒ Object 



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# File 'lib/denko/display/st7565.rb', line 19

def standby
  command [DISPLAY_OFF, ALL_POINTS_ON]
end

#volume=(value) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/denko/display/st7565.rb', line 48

def volume=(value)
  raise ArgumentError, "invalid volume #{value}" unless VALID_VOLUMES.include? value
  command [VOLUME, value]
end

#wake ⇒ Object 



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# File 'lib/denko/display/st7565.rb', line 27

def wake
  # Note static indicator stays disabled. Not sure how to use it.
  command [ALL_POINTS_OFF, DISPLAY_ON, STATIC_INDICATOR_OFF, 0b00]
end

#x_ram_offset ⇒ Object 



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# File 'lib/denko/display/st7565.rb', line 77

def x_ram_offset
  @x_ram_offset ||= 0
end