PicoRuby Quotes Downloader (with waveshare 2.9 inch e-paper display)

quotes.rb

# configure wifi first using ncli

require 'spi'
require 'gpio'
require 'net/http'

class Epaper
  BUSY = 1
  WS_20_30 = [
    0x80,0x66,0x00,0x00,0x00,0x00,0x00,0x00,0x40,0x00,0x00,0x00,
    0x10,0x66,0x00,0x00,0x00,0x00,0x00,0x00,0x20,0x00,0x00,0x00,
    0x80,0x66,0x00,0x00,0x00,0x00,0x00,0x00,0x40,0x00,0x00,0x00,
    0x10,0x66,0x00,0x00,0x00,0x00,0x00,0x00,0x20,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    0x14,0x08,0x00,0x00,0x00,0x00,0x02,
    0x0A,0x0A,0x00,0x0A,0x0A,0x00,0x01,
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    0x14,0x08,0x00,0x01,0x00,0x00,0x01,
    0x00,0x00,0x00,0x00,0x00,0x00,0x01,
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    0x44,0x44,0x44,0x44,0x44,0x44,0x00,0x00,0x00,
    0x22,0x17,0x41,0x00,0x32,0x36
  ]
  FONT = [
    0x18,0x24,0x42,0x7E,0x42,0x42,0x42,
    0x7C,0x42,0x7C,0x42,0x42,0x42,0x7C,
    0x3C,0x42,0x40,0x40,0x40,0x42,0x3C,
    0x78,0x44,0x42,0x42,0x42,0x44,0x78,
    0x7E,0x40,0x7E,0x40,0x40,0x40,0x7E,
    0x7E,0x40,0x7E,0x40,0x40,0x40,0x40,
    0x3C,0x42,0x40,0x4E,0x42,0x42,0x3C,
    0x42,0x42,0x7E,0x42,0x42,0x42,0x42,
    0x7C,0x10,0x10,0x10,0x10,0x10,0x7C,
    0x3E,0x04,0x04,0x04,0x04,0x44,0x38,
    0x44,0x48,0x70,0x48,0x44,0x42,0x42,
    0x40,0x40,0x40,0x40,0x40,0x40,0x7E,
    0x42,0x66,0x5A,0x42,0x42,0x42,0x42,
    0x42,0x62,0x52,0x4A,0x46,0x42,0x42,
    0x3C,0x42,0x42,0x42,0x42,0x42,0x3C,
    0x7C,0x42,0x42,0x7C,0x40,0x40,0x40,
    0x3C,0x42,0x42,0x42,0x4A,0x44,0x3A,
    0x7C,0x42,0x42,0x7C,0x44,0x42,0x42,
    0x3C,0x42,0x40,0x3C,0x02,0x42,0x3C,
    0x7E,0x10,0x10,0x10,0x10,0x10,0x10,
    0x42,0x42,0x42,0x42,0x42,0x42,0x3C,
    0x42,0x42,0x42,0x24,0x24,0x18,0x18,
    0x42,0x42,0x42,0x5A,0x5A,0x66,0x42,
    0x42,0x24,0x18,0x18,0x24,0x42,0x42,
    0x42,0x24,0x18,0x10,0x10,0x10,0x10,
    0x7E,0x04,0x08,0x10,0x20,0x40,0x7E,
    0x3C,0x42,0x46,0x5A,0x62,0x42,0x3C,
    0x10,0x30,0x10,0x10,0x10,0x10,0x7C,
    0x3C,0x42,0x02,0x0C,0x10,0x20,0x7E,
    0x3C,0x42,0x02,0x1C,0x02,0x42,0x3C,
    0x04,0x0C,0x14,0x24,0x7E,0x04,0x04,
    0x7E,0x40,0x7C,0x02,0x02,0x42,0x3C,
    0x3C,0x42,0x40,0x7C,0x42,0x42,0x3C,
    0x7E,0x02,0x04,0x08,0x10,0x20,0x40,
    0x3C,0x42,0x42,0x3C,0x42,0x42,0x3C,
    0x3C,0x42,0x42,0x3E,0x02,0x42,0x3C,
    0x00,0x00,0x00,0x00,0x00,0x00,0x18,
    0x00,0x00,0x00,0x00,0x00,0x18,0x10,
    0x00,0x18,0x00,0x00,0x00,0x18,0x00,
    0x10,0x10,0x10,0x10,0x10,0x00,0x10,
    0x3C,0x42,0x02,0x0C,0x10,0x00,0x10,
    0x00,0x00,0x00,0x7E,0x00,0x00,0x00,
    0x10,0x10,0x20,0x00,0x00,0x00,0x00,
    0x02,0x04,0x08,0x10,0x20,0x40,0x40
  ]

  def initialize
    @rst = GPIO.new(12, GPIO::OUT)
    @busy = GPIO.new(13, GPIO::IN)
    @cs = GPIO.new(9, GPIO::OUT)
    @dc = GPIO.new(8, GPIO::OUT)
    @busy.set_pull(GPIO::PULL_UP)
    @cs.write(1)
    @dc.write(1)
    @rst.write(1)
    @spi = SPI.new(unit: :RP2040_SPI1, frequency: 4000_000, mode: 0, cs_pin: -1, sck_pin: 10, copi_pin: 11)
    @white = Array.new(128, 0xFF)
    @chunk = Array.new(128, 0xFF)
  end

  def cmd(c) @dc.write(0); @cs.write(0); @spi.write([c]); @cs.write(1) end
  def dat(d) @dc.write(1); @cs.write(0); @spi.write(d.is_a?(Array) ? d : [d]); @cs.write(1) end
  def busy() while @busy.read == 1 do sleep_ms 10 end end

  def init
    @rst.write(1); sleep_ms(50); @rst.write(0); sleep_ms(10); @rst.write(1); sleep_ms(50)
    busy; cmd(0x12); busy
    cmd(0x01); dat([0x27,0x01,0x00])
    cmd(0x11); dat([0x03])
    cmd(0x44); dat([0x00,0x0F])
    cmd(0x45); dat([0x00,0x00,0x27,0x01])
    cmd(0x21); dat([0x00,0x80])
    cmd(0x4E); dat([0x00]); cmd(0x4F); dat([0x00,0x00]); busy
    cmd(0x32)
    i = 0
    while i < 153 do dat([WS_20_30[i]]); i += 1 end
    busy
    cmd(0x3F); dat([WS_20_30[153]])
    cmd(0x03); dat([WS_20_30[154]])
    cmd(0x04); dat([WS_20_30[155],WS_20_30[156],WS_20_30[157]])
    cmd(0x2C); dat([WS_20_30[158]])
  end

  def clear
    init
    cmd(0x24); i=0; while i<37 do white_chunk; i+=1 end
    cmd(0x26); i=0; while i<37 do white_chunk; i+=1 end
    cmd(0x22); dat([0xC7]); cmd(0x20); busy
  end

  def glyph(c, r)
    o = c.ord
    return 0x00 if o == 32
    if o >= 65 && o <= 90 then o = o - 65
    elsif o >= 97 && o <= 122 then o = o - 97
    else
      case c
      when '0' then o=26; when '1' then o=27; when '2' then o=28
      when '3' then o=29; when '4' then o=30; when '5' then o=31
      when '6' then o=32; when '7' then o=33; when '8' then o=34
      when '9' then o=35; when '.' then o=36; when ',' then o=37
      when ':' then o=38; when '!' then o=39; when '?' then o=40
      when '-' then o=41; when '\'' then o=42; when '/' then o=43
      else return 0x00
      end
    end
    FONT[o * 7 + r]
  end

  def white_chunk
    @dc.write(1); @cs.write(0); @spi.write(@white); @cs.write(1)
  end

  # Landscape display 2x scaled: 296 wide x 128 tall
  # 18 chars/line, 8 lines (16px each: 14 glyph + 2 space)
  # Rotated 90 CCW: hold bottom of display to the left
  def display_landscape(lines)
    cmd(0x4E); dat([0x00]); cmd(0x4F); dat([0x00,0x00]); busy
    cmd(0x24)

    dy = 0
    while dy < 296
      ci = 0
      ri = 0
      while ri < 8 && dy + ri < 296
        lx = 295 - (dy + ri)
        char_col = lx / 16
        char_px = (lx % 16) / 2
        char_px = 7 - char_px

        bx = 0
        while bx < 16
          byte_val = 0xFF
          bp = 0
          while bp < 8
            dx = bx * 8 + bp
            text_line = dx / 16
            char_py = (dx % 16) / 2

            if char_py < 7 && text_line < lines.length
              line = lines[text_line]
              if char_col < line.length
                g = glyph(line[char_col], char_py)
                if (g >> char_px) & 1 == 1
                  byte_val = byte_val & (0xFF ^ (0x80 >> bp))
                end
              end
            end
            bp += 1
          end
          @chunk[ci] = byte_val
          ci += 1
          bx += 1
        end
        ri += 1
      end
      dat(@chunk)
      dy += 8
    end

    cmd(0x22); dat([0xC7]); cmd(0x20); busy
  end
end

def wrap(text, w)
  lines = []
  line = ""
  words = text.split(" ")
  wi = 0
  while wi < words.length
    word = words[wi]
    if line.length == 0
      line = word
    elsif line.length + 1 + word.length <= w
      line = line + " " + word
    else
      lines << line
      line = word
    end
    wi += 1
  end
  lines << line if line.length > 0
  lines
end

epd = Epaper.new
epd.init
epd.clear



loop do
  quote = "No quote"
  author = ""
  begin
    puts "Fetching quote..."
    http = Net::HTTP.new("zenquotes.io", 443)
    http.use_ssl = true
    response = http.get("/api/random")
    body = response.body
    response = nil
    http = nil

    if body != nil && body.length > 0
      qi = body.index("\"q\":\"")
      if qi != nil
        qi += 5
        qe = body.index("\"", qi)
        quote = body[qi, qe - qi] if qe != nil
      end
      ai = body.index("\"a\":\"")
      if ai != nil
        ai += 5
        ae = body.index("\"", ai)
        author = body[ai, ae - ai] if ae != nil
      end
    end
    body = nil
  rescue => e
    puts "HTTP error: #{e}"
    Machine.reboot
  end

  puts "Quote: #{quote}"
  lines = wrap(quote, 18)
  lines << ""
  lines << "- #{author}" if author.length > 0

  epd.clear
  epd.display_landscape(lines)
  lines = nil
  GC.start
  sleep 10
end