Ruby bindings for the raspberry pi LCD interface

Known issues:

• one needs to be root in order to run all this
• FIXED NOW: it seems that one needs to execute ext/RaspiLCD-V0.9.0/raspilcd first in order to see something on the display (you can quit raspilcd with ctrl+c immediately)

This gem provides a module RaspiLCD, with the following methods:

  clear_screen
  set_pen_color(color)
  set_fill_color(color)
  set_font(font)
  set_contrast(contrast)

  put_pixel(x,y,color)
  draw_line(x0,y0,x1,y1)
  draw_circle(x,y,radius)
  draw_ellipse(xm,ym,a,b)
  draw_rect(x0,y0,x1,y1,line)
  print_xy(x,y,string)
  print_encoded_xy(x,y,string) # use this one for umlauts etc. Requires ruby > 1.9
  draw_bitmap(x,y,bmp)

  init
  write_framebuffer

  raspi_lcd_hw_init
  update_buttons
  get_raspberry_hw_revision
  spi_putc(d)
  set_backlight(light)
  sleep_ms(ms)
  button(b)         # b can be :up, :left, :center, :right, :down 
  button_pressed(b) # b can be :up, :left, :center, :right, :down 
  buttons
  buttons_pressed