upm/src/ht9170/ht9170.cxx

/*
 * Author: Jon Trulson <jtrulson@ics.com>
 * Copyright (c) 2015 Intel Corporation.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <iostream>

#include "ht9170.h"

using namespace upm;
using namespace std;

HT9170::HT9170(int dr, int o1, int o2, int o3, int o4)
{
  // init the gpio's we will need
  if ( !(m_dr = mraa_gpio_init(dr)) )
    {
      cerr << __FUNCTION__ << ": mraa_gpio_init(dr) failed" << endl;
      return;
    }
  mraa_gpio_dir(m_dr, MRAA_GPIO_IN);

  if ( !(m_o1 = mraa_gpio_init(o1)) )
    {
      cerr << __FUNCTION__ << ": mraa_gpio_init(o1) failed" << endl;
      return;
    }
  mraa_gpio_dir(m_o1, MRAA_GPIO_IN);

  if ( !(m_o2 = mraa_gpio_init(o2)) )
    {
      cerr << __FUNCTION__ << ": mraa_gpio_init(o2) failed" << endl;
      return;
    }
  mraa_gpio_dir(m_o2, MRAA_GPIO_IN);

  if ( !(m_o3 = mraa_gpio_init(o3)) )
    {
      cerr << __FUNCTION__ << ": mraa_gpio_init(o3) failed" << endl;
      return;
    }
  mraa_gpio_dir(m_o3, MRAA_GPIO_IN);

  if ( !(m_o4 = mraa_gpio_init(o4)) )
    {
      cerr << __FUNCTION__ << ": mraa_gpio_init(o4) failed" << endl;
      return;
    }
  mraa_gpio_dir(m_o4, MRAA_GPIO_IN);
}

HT9170::~HT9170()
{
  mraa_gpio_close(m_dr);
  mraa_gpio_close(m_o1);
  mraa_gpio_close(m_o2);
  mraa_gpio_close(m_o3);
  mraa_gpio_close(m_o4);
}

bool HT9170::digitReady()
{
  return (mraa_gpio_read(m_dr) ? true : false);
}

char HT9170::decodeDigit()
{
  // This lookup table is derived from the decode table on page 7 of
  // the HT9170B/HT9170D datasheet.

  static const char decode[16] = {
    'D',     // 0
    '1',     // 1
    '2',     // 2
    '3',     // 3
    '4',     // 4
    '5',     // 5
    '6',     // 6
    '7',     // 7
    '8',     // 8
    '9',     // 9
    '0',     // 10
    '*',     // 11
    '#',     // 12
    'A',     // 13
    'B',     // 14
    'C'      // 15
  };

  uint8_t bits = 0;

  bits = mraa_gpio_read(m_o1);
  bits |= (mraa_gpio_read(m_o2) << 1);
  bits |= (mraa_gpio_read(m_o3) << 2);
  bits |= (mraa_gpio_read(m_o4) << 3);

  return decode[bits];
}