class RpiLcd16x2

Public Class Methods

new(string='', p_rs: 11, p_en: 10, d4: 6, d5: 5, d6: 4, d7: 1) click to toggle source

# File lib/rpi_lcd16x2.rb, line 13
def initialize(string='', p_rs: 11, p_en: 10, d4: 6, d5: 5, d6: 4, d7: 1)

  @p_rs, @p_en, @d4, @d5, @d6, @d7 = p_rs, p_en, d4, d5, d6, d7

  Wiringpi.wiringPiSetup

  # Set all pins to output mode
  [p_rs, p_en, d7, d6, d5, d4].each {|pin,val| Wiringpi.pinMode(pin, 1)}

  function_set # sets the display to use 4-bit instructions
  cursor_off
  print string unless string.empty?
end

Public Instance Methods

cls() click to toggle source

Clear all data from screen

# File lib/rpi_lcd16x2.rb, line 29
def cls() cmd d4: 1                       end

cursor(direction=1) click to toggle source

# File lib/rpi_lcd16x2.rb, line 31
def cursor(direction=1) cmd d7: 1, d6: direction, d5: nil, d4: nil end

cursor_off() click to toggle source

# File lib/rpi_lcd16x2.rb, line 32
def cursor_off()  cmd d7: 1, d6: 1, d5: 0 end

cursor_on() click to toggle source

# File lib/rpi_lcd16x2.rb, line 33
def cursor_on()   cmd d7: 1, d6: 1, d5: 1 end

display_off() click to toggle source

# File lib/rpi_lcd16x2.rb, line 34
def display_off() cmd d7: 1               end

display_on() click to toggle source

# File lib/rpi_lcd16x2.rb, line 35
def display_on()  cmd d7: 1, d6: 1        end

entry(direction=1) click to toggle source

Sets cursor move direction (I/D); specifies to shift the display (S). I/D - increment = 1 or decrement = 0 S - 0 = no display shift, 1 = display shift e.g. 0 0 0 0 1 D C B

# File lib/rpi_lcd16x2.rb, line 42
def entry(direction=1)
  write_command rs: 1, d7: 0, d6: 0,         d5: 0,   d4: 1
  write_command rs: 1, d7: 0, d6: direction, d5: nil, d4: nil
end

home() click to toggle source

# File lib/rpi_lcd16x2.rb, line 55
def home()        cmd d5: 1               end

lcd_write(a) click to toggle source

Write data to CGRAM/DDRAM

# File lib/rpi_lcd16x2.rb, line 49
def lcd_write(a)

  write_command rs: 1, d7: a[0], d6: a[1], d5: a[2], d4: a[3]
  write_command rs: 1, d7: a[4], d6: a[5], d5: a[6], d4: a[7]
end

print(raw_s) click to toggle source

# File lib/rpi_lcd16x2.rb, line 58
def print(raw_s)
  cls
  s = raw_s.split(/\n/).map {|x| x.ljust(40)}.join
  print_text s
end

Also aliased as: text

print_text(s) click to toggle source

# File lib/rpi_lcd16x2.rb, line 66
def print_text(s)

  s.each_byte.to_a.each do |x|
    lcd_write ("%08b" % x).each_char.to_a.map(&:to_i)
  end
end

text(raw_s)

Alias for: print

Protected Instance Methods

cmd(h) click to toggle source

# File lib/rpi_lcd16x2.rb, line 75
def cmd(h) write_command; write_command h;  sleep 0.001  end

function_set() click to toggle source

Sets interface data length (DL), number of display line (N),

and character font (F).

DL - 0 = 4-bit interface, 1 = 8-bit interface N - 0 = 1/8 or 1/11 duty (1 line), 1 = 1/16 duty (2 lines) F - 0 = 5×8 dots, 1 = 5×10 dots e.g. 0 0 1 DL N F * *

d7 d6 d5 d4  d7 d6 d5 d4

# File lib/rpi_lcd16x2.rb, line 84
def function_set()
  write_command rs: 0, d7: 0, d6: 0, d5: 1,   d4: 0
  write_command rs: 0, d7: 1, d6: 0, d5: nil, d4: nil
end

write_command(rs: 0, d7: 0, d6: 0, d5: 0, d4: 0) click to toggle source

# File lib/rpi_lcd16x2.rb, line 89
def write_command(rs: 0, d7: 0, d6: 0, d5: 0, d4: 0)

  [@p_rs, @d7, @d6, @d5, @d4,].zip([rs,d7,d6,d5,d4]).each do |pin,val| 
    Wiringpi.digitalWrite(pin, val) if val
  end
  pulse_enable()
end

Private Instance Methods

pulse_enable() click to toggle source

Indicate to LCD that command should be 'executed'

# File lib/rpi_lcd16x2.rb, line 101
def pulse_enable()
  [1,0].each {|x| Wiringpi.digitalWrite(@p_en, x)}
end