Tracking Olympic Medals with the Raspberry Pi

medals.py

import sys, urllib
from time import sleep
import spidev

def spi_send(bus, data):
  xfer_list = []
  if type(data) == str:
    for c in data:
      xfer_list.append(ord(c))
  elif type(data) == list:
    xfer_list += data
  elif type(data) == int:
    xfer_list.append(data)
  else:
    print "Unsupported type passed to spi_send. Must be str, int, or list"

  bus.xfer2(xfer_list, 250000)

def clear_display(bus):
  spi_send(bus, [0x76])

def display_medal_counts(bus, gold, silver, bronze):
    total = gold + silver + bronze
    totalstr = "to" + str(total)
    goldstr = "go" + str(gold)
    silverstr = "si" + str(silver)
    bronzestr = "br" + str(bronze)

    for i in range(3):
        clear_display(bus)
        spi_send(bus, totalstr)
        spi_send(bus, [0x77, 0x10])
        sleep(4)

        clear_display(bus)
        spi_send(bus, goldstr)
        spi_send(bus, [0x77, 0x10])
        sleep(4)

        clear_display(bus)
        spi_send(bus, silverstr)
        spi_send(bus, [0x77, 0x10])
        sleep(4)

        clear_display(bus)
        spi_send(bus, bronzestr)
        spi_send(bus, [0x77, 0x10])
        sleep(4)

try:
    import lxml.html
except ImportError:
    print "You need to install the lxml module first. Use 'sudo apt-get install python-lxml'"
    sys.exit(1)

print("Press Ctrl-C to exit")
print("")

# Setup spi module
spi = spidev.SpiDev()
spi.open(0,0)

try:
  while True:
    sys.stdout.write('Counting Medals.....')
    sys.stdout.flush()

    # Add a delay for effect
    sleep(2)

    page = urllib.urlopen("http://www.nbcolympics.com/medals").read()
    html = lxml.html.fromstring(page)
    result = html.xpath('//a[text()=" United States of America"]/@href')
    nameNode = result[0].getparent().getparent()

    goldNode = nameNode.getnext()
    silverNode = goldNode.getnext()
    bronzeNode = silverNode.getnext()

    gold_count = int(goldNode.text_content().strip())
    silver_count = int(silverNode.text_content().strip())
    bronze_count = int(bronzeNode.text_content().strip())

    # Display each count 3 times and then check again
    display_medal_counts(spi, gold_count, silver_count, bronze_count)

except KeyboardInterrupt:
  clear_display(spi)
  spi.close()
  sys.exit(0)