Class: I2C::AlphaDisplay

Inherits:
Object
  • Object
show all
Defined in:
lib/i2c/alpha_display.rb,
lib/i2c/alpha_display/version.rb

Constant Summary collapse

DEVICE_ID = 
0x70
HT16K33_SYSTEM_SETUP = 
0x20
HT16K33_OSCILLATOR = 
0x01
HT16K33_CMD_BRIGHTNESS = 
0xE0
0x80
0x01
0x00
0x02
0x04
0x06
DIGIT_VALUES = 
{
  ' ' => 0b0000000000000000,
  '+' => 0b0001001011000000,
  '-' => 0b0000000011000000,
  '0' => 0b0000110000111111,
  '1' => 0b0000000000000110,
  '2' => 0b0000000011011011,
  '3' => 0b0000000010001111,
  '4' => 0b0000000011100110,
  '5' => 0b0010000001101001,
  '6' => 0b0000000011111101,
  '7' => 0b0000000000000111,
  '8' => 0b0000000011111111,
  '9' => 0b0000000011101111,
  'A' => 0b0000000011110111,
  'B' => 0b0001001010001111,
  'C' => 0b0000000000111001,
  'D' => 0b0001001000001111,
  'E' => 0b0000000011111001,
  'F' => 0b0000000001110001,
  'G' => 0b0000000010111101,
  'H' => 0b0000000011110110,
  'I' => 0b0001001000000000,
  'J' => 0b0000000000011110,
  'K' => 0b0010010001110000,
  'L' => 0b0000000000111000,
  'M' => 0b0000010100110110,
  'N' => 0b0010000100110110,
  'O' => 0b0000000000111111,
  'P' => 0b0000000011110011,
  'Q' => 0b0010000000111111,
  'R' => 0b0010000011110011,
  'S' => 0b0000000011101101,
  'T' => 0b0001001000000001,
  'U' => 0b0000000000111110,
  'V' => 0b0000110000110000,
  'W' => 0b0010100000110110,
  'X' => 0b0010110100000000,
  'Y' => 0b0001010100000000,
  'Z' => 0b0000110000001001	
}
VERSION = 
"0.5.1"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(device_id = DEVICE_ID, should_init = true) ⇒ AlphaDisplay

Returns a new instance of AlphaDisplay.



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# File 'lib/i2c/alpha_display.rb', line 64

def initialize(device_id = DEVICE_ID, should_init = true)
  @display_size = 4
  @device = WiringPi::I2C.new device_id
  @buffer_size = 16
  @buffer = []
  @device_id = device_id

  self.debug = false
  self.clear

  # init the device to the default state, if thats what we want
  if should_init
    self.display_init
  end
end

Instance Attribute Details

#debug ⇒ Object

Returns the value of attribute debug.



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# File 'lib/i2c/alpha_display.rb', line 62

def debug
  @debug
end

Class Method Details

.open(device_id = DEVICE_ID) ⇒ Object 



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# File 'lib/i2c/alpha_display.rb', line 86

def self.open(device_id = DEVICE_ID)
  return AlphaDisplay.new(device_id, false)
end

Instance Method Details

#blank ⇒ Object 



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# File 'lib/i2c/alpha_display.rb', line 91

def blank()
  self.clear()
  self.write_buffer
end

#blink=(v) ⇒ Object 



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# File 'lib/i2c/alpha_display.rb', line 114

def blink=(v)
  raise if ![HT16K33_BLINK_OFF, HT16K33_BLINK_2HZ, HT16K33_BLINK_1HZ, HT16K33_BLINK_HALFHZ].include? v
  @device.write HT16K33_BLINK_CMD | HT16K33_BLINK_DISPLAYON | v.to_i
end

#brightness=(v) ⇒ Object 



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# File 'lib/i2c/alpha_display.rb', line 102

def brightness=(v)
  @device.write HT16K33_CMD_BRIGHTNESS | (v.to_i & 0xf)
end

#clear ⇒ Object 



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# File 'lib/i2c/alpha_display.rb', line 96

def clear()
  @buffer_size.times do |i|
    @buffer[i] = 0
  end
end

#display_init ⇒ Object 



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# File 'lib/i2c/alpha_display.rb', line 80

def display_init
  @device.write HT16K33_SYSTEM_SETUP | HT16K33_OSCILLATOR
  self.stop_blink
  self.brightness = 1
end

#set(s, rjust = true) ⇒ Object 



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# File 'lib/i2c/alpha_display.rb', line 119

def set(s, rjust = true)
  if s.respond_to? :to_alpha
    s = s.to_alpha
  end
  
  s = s.to_s
  s_no_decimals = s.gsub('.', '')

  puts s if self.debug

  if rjust && s_no_decimals.length < @display_size
    decimal_count = s.length - s_no_decimals.length
    s = s.rjust(@display_size + decimal_count)
  end

  addr = 0
  (0..s.length-1).each do |pos|
    next if s[pos] == '.'

    decimal = (s[pos+1] == '.' && addr != @display_size -1)
    write_char addr, s[pos], decimal
    addr += 1

    break if addr >= @display_size
  end

  self.write_buffer
end

#start_blink(type = HT16K33_BLINK_1HZ) ⇒ Object 



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# File 'lib/i2c/alpha_display.rb', line 106

def start_blink(type = HT16K33_BLINK_1HZ)
  self.blink = type
end

#stop_blink ⇒ Object 



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# File 'lib/i2c/alpha_display.rb', line 110

def stop_blink
  self.blink = HT16K33_BLINK_OFF
end

#write_buffer ⇒ Object 



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# File 'lib/i2c/alpha_display.rb', line 161

def write_buffer
  @buffer_size.times do |i|
    @device.write_reg_8 i, @buffer[i] & 0xFF
  end
end

#write_char(pos, c, decimal = false) ⇒ Object 



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# File 'lib/i2c/alpha_display.rb', line 148

def write_char(pos, c, decimal = false)
  raise "Invalid address (#{pos})" if pos >= @display_size || pos.class != Fixnum
  raise "Expecting string data, but got #{c.class}" if c.class != String
  raise "Can only set a single character (string length is #{c.length})" if c.length != 1

  a = DIGIT_VALUES[c.upcase[0]]
  raise "Character not in character set (#{c})" if a.nil?
  
  a = a | 0x4000 if decimal
  @buffer[pos*2] = a & 0xff
  @buffer[pos*2+1] = (a >> 8) & 0xff
end