import smbus
import time

after = ''

CHANNEL = 1
ICADDR = 0x20
REG_IODIRA = 0x00 # GPAの方向レジスタ
REG_IODIRB = 0x01 # GPBの方向レジスタ
REG_GPIOA = 0x12 # GPAの入力データレジスタ
REG_OLATA = 0x14 # GPAの出力データレジスタ
REG_GPIOB = 0x13 # GPBの入力データレジスタ
REG_OLATB = 0x15 # GPBの出力データレジスタ

i2c = smbus.SMBus(CHANNEL)

#i2c.write_byte_data(ICADDR, REG_IODIRA, 0x00) # GPAを全て出力に設定
#i2c.write_byte_data(ICADDR, REG_IODIRB, 0xFF) # GPBを全て入力に設定
i2c.write_byte_data(ICADDR, REG_IODIRA, 0xFF) # GPAを全て入力に設定
i2c.write_byte_data(ICADDR, REG_IODIRB, 0x00) # GPBを全て出力に設定

try:
    while True:
#        sw = i2c.read_byte_data(ICADDR, REG_GPIOB) #GPBの読み込み
#        i2c.write_byte_data(ICADDR, REG_OLATA, sw) #GPAへGPBの値を出力
        sw = i2c.read_byte_data(ICADDR, REG_GPIOA) #GPAの読み込み
#        print(bin(sw))
        if (sw == 0b11111110):
            print('N')
            after = 'N'
        elif(sw == 0b11111101):
            print('NE')
            after = 'NE'
        elif(sw == 0b11111011):
            print('E')
            after = 'E'
        elif(sw == 0b11110111):
            print('SE')
            after = 'SE'
        elif(sw == 0b11101111):
            print('S')
            after = 'S'
        elif(sw == 0b11011111):
            print('SW')
            after = 'SW'
        elif(sw == 0b10111111):
            print('W')
            after = 'W'
        elif(sw == 0b01111111):
            print('NW')
            after = 'NW'
        else:
            print(after)
        time.sleep(5)
    
except KeyboardInterrupt:
    pass

finally:
    print('END')