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/*
* Author: Jon Trulson <jtrulson@ics.com>
* Copyright (c) 2014 Intel Corporation.
*
* Adapted from Seeed Studio library:
* https://github.com/Seeed-Studio/RTC_DS1307
*
* 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 <string>
#include <stdexcept>
#include "ds1307.hpp"
using namespace upm;
using namespace std;
DS1307::DS1307(int bus) : m_i2c(bus)
{
// setup our i2c link
mraa::Result ret = m_i2c.address(DS1307_I2C_ADDR);
if (ret != mraa::SUCCESS){
throw std::invalid_argument(std::string(__FUNCTION__) +
": i2c.address() failed");
return;
}
}
mraa::Result DS1307::writeBytes(uint8_t reg, uint8_t *buffer, int len)
{
if (!len || !buffer)
return mraa::ERROR_INVALID_PARAMETER;
// create a buffer 1 byte larger than the supplied buffer,
// store the register in the first byte
uint8_t buf2[len + 1];
buf2[0] = reg;
// copy in the buffer after the reg byte
for (int i=1; i<(len + 1); i++)
buf2[i] = buffer[i-1];
mraa::Result ret = m_i2c.address(DS1307_I2C_ADDR);
if (ret != mraa::SUCCESS){
throw std::invalid_argument(std::string(__FUNCTION__) +
": i2c.address() failed");
return ret;
}
return m_i2c.write(buf2, len + 1);
}
int DS1307::readBytes(uint8_t reg, uint8_t *buffer, int len)
{
if (!len || !buffer)
return 0;
mraa::Result ret = m_i2c.address(DS1307_I2C_ADDR);
if (ret != mraa::SUCCESS){
throw std::invalid_argument(std::string(__FUNCTION__) +
": i2c.address() failed");
return 0;
}
m_i2c.writeByte(reg);
return m_i2c.read(buffer, len);
}
bool DS1307::loadTime()
{
// read the first 7 registers
uint8_t buffer[7];
int bytesRead = readBytes(0, buffer, 7);
if (bytesRead != 7)
{
// problem
throw std::runtime_error(std::string(__FUNCTION__) +
": failed to read expected 7 bytes from device");
return false;
}
// We need to mask some control bits off of some of these values
// and convert the result to decimal from BCD. We also need to account
// for format (AM/PM or 24hr), and if AM/PM, whether PM should be set.
// first bit here is the oscillator enable/disable bit
seconds = bcdToDec(buffer[0] & 0x7f);
minutes = bcdToDec(buffer[1]);
// check AM/PM or 24hr mode
if (buffer[2] & 0x40)
{
// We are in AM/PM mode
hours = bcdToDec(buffer[2] & 0x1f);
amPmMode = true;
pm = (buffer[2] & 0x20) ? true : false;
}
else
{
// 24hr mode
hours = bcdToDec(buffer[2] & 0x3f);
amPmMode = false;
pm = false;
}
dayOfWeek = bcdToDec(buffer[3]);
dayOfMonth = bcdToDec(buffer[4]);
month = bcdToDec(buffer[5]);
year = bcdToDec(buffer[6]);
return true;
}
bool DS1307::setTime()
{
uint8_t buffer[7];
// seconds
// we need to read in seconds first to preserve the osc enable bit
uint8_t tmpbuf;
readBytes(0, &tmpbuf, 1);
buffer[0] = decToBcd(seconds) | (tmpbuf & 0x80);
// minutes
buffer[1] = decToBcd(minutes);
// hours
if (amPmMode)
{
buffer[2] = decToBcd(hours) | 0x40;
if (pm)
buffer[2] |= 0x20;
}
else
buffer[2] = decToBcd(hours);
// day of week
buffer[3] = decToBcd(dayOfWeek);
// day of month
buffer[4] = decToBcd(dayOfMonth);
// month
buffer[5] = decToBcd(month);
// year
buffer[6] = decToBcd(year);
return writeBytes(0, buffer, 7);
}
mraa::Result DS1307::enableClock()
{
// the oscillator enable bit is the high bit of reg 0
// so read it, clear it, and write it back.
uint8_t buf;
readBytes(0, &buf, 1);
buf &= ~0x80;
return writeBytes(0, &buf, 1);
}
mraa::Result DS1307::disableClock()
{
// the oscillator enable bit is the high bit of reg 0
// so read it, set it, and write it back.
uint8_t buf;
readBytes(0, &buf, 1);
buf |= 0x80;
return writeBytes(0, &buf, 1);
}
// Convert decimal to BCD
uint8_t DS1307::decToBcd(unsigned int val)
{
return ( (val/10*16) + (val%10) );
}
// Convert BCD to decimal
unsigned int DS1307::bcdToDec(uint8_t val)
{
return ( (val/16*10) + (val%16) );
}
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