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/*
* Author: Jon Trulson <jtrulson@ics.com>
* Copyright (c) 2016 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 <time.h>
#include <stdexcept>
#include "ds2413.hpp"
using namespace upm;
using namespace std;
DS2413::DS2413(int uart) :
m_uart(uart)
{
m_devicesFound = 0;
// check basic access to the 1-wire bus (presence detect)
mraa::Result rv;
if ((rv = m_uart.reset()) != mraa::SUCCESS)
{
throw std::runtime_error(std::string(__FUNCTION__) +
": reset() failed, no devices on bus?");
return;
}
}
DS2413::~DS2413()
{
}
void DS2413::init()
{
// iterate through the bus and build up a list of detected DS2413
// devices (only)
// empty the map, in case this method has already been run once
// before
m_devicesFound = 0;
m_deviceMap.clear();
// start the search from scratch
string id = m_uart.search(true);
if (id.empty())
{
throw std::runtime_error(std::string(__FUNCTION__) +
": no devices detected on bus");
return;
}
while (!id.empty())
{
// The first byte (id[0]]) is the device type (family) code. We
// are only interested in the family code for this device (0x3a).
if ((uint8_t)id[0] == DS2413_FAMILY_CODE)
{
// we have a winner, add it to our map and continue searching
m_deviceMap[m_devicesFound] = id;
m_devicesFound++;
}
// continue search
id = m_uart.search(false);
}
if (!m_devicesFound)
{
throw std::runtime_error(std::string(__FUNCTION__) +
": no DS2413 devices found on bus");
return;
}
}
int DS2413::readGpios(int index)
{
if (index < 0 || index >= m_devicesFound)
{
throw std::out_of_range(std::string(__FUNCTION__) +
": device index out of range");
return 0;
}
m_uart.command(ACCESS_READ, m_deviceMap[index]);
uint8_t value = m_uart.readByte();
// Validity is performed by taking the high nibble, inverting it, and
// copmpating it to the low nibble. If they are equal, then the
// data is good.
if ( (value & 0x0f) != ((~value >> 4) & 0x0f) )
{
throw std::runtime_error(std::string(__FUNCTION__) +
": returned value failed integrity check");
return 0;
}
m_uart.reset();
// Only the 4 lsb's are relevant
return (value & 0x0f);
}
void DS2413::writeGpios(int index, int value)
{
if (index < 0 || index >= m_devicesFound)
{
throw std::out_of_range(std::string(__FUNCTION__) +
": device index out of range");
return;
}
// mask out everything but the first 2 bits
uint8_t val = (uint8_t)value & 0x03;
// the value must have the upper 8 bits written set to 1's
val |= 0xfc;
m_uart.command(ACCESS_WRITE, m_deviceMap[index]);
// first we write the new value, then the inverted value
m_uart.writeByte(val);
m_uart.writeByte(~val);
// now we read back a response indicating success or failure
uint8_t resp = m_uart.readByte();
if (resp != ACK_SUCCESS)
{
throw std::runtime_error(std::string(__FUNCTION__) +
": failed response validation");
return;
}
m_uart.reset();
return;
}
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