#!/usr/bin/env python3

import time

import sys

# appends to PYTHONPATH the location of the example codes

sys.path.append(r'/home/pi/git/quick2wire-python-api/')

import quick2wire.i2c as q2w_i2c

import twitalu_globals as globals

# Useful port expander registers

IODIRA = 0x00

IODIRB = 0x01

IPOLA = 0x02

IPOLB = 0x03

GPPUA = 0x0C

GPPUB = 0x0D

GPIOA = 0x12

GPIOB = 0x13

# Each of the following functions require these arguments:

# port_expand_addr = {0x20, 0x21, 0x22} (hex address)

# port = {A, B} (expander port)

# value = {0b00000000} (8-bit data value)

# This function sets the port's pull up resistors

# For pull-up, value = 0b11111111. Port must be set to input.

def set_IO_PULL_UP(port_expand_addr, port, value):

q2w_i2c.writing_bytes(port_expand_addr, GPPUB, value))

# This function sets the port's logic polarity

# For inverting, value = 0b11111111. For non-inverting, value = 0b00000000

def set_IO_POL(port_expand_addr, port, value):

q2w_i2c.writing_bytes(port_expand_addr, IPOLB, value))

# This function sets the direction of a port's GPIO

# For input, value = 0b11111111. For output, value = 0b00000000

def set_IO_DIR(port_expand_addr, port, value):

q2w_i2c.writing_bytes(port_expand_addr, IODIRB, value))

# This function writes data to the port expander

def write_data(port_expand_addr, port, value):

q2w_i2c.writing_bytes(port_expand_addr, GPIOB, value))

# This function reads data from the port expander

def read_data(port_expand_addr, port):