Diff: RTC/ds3231m.cpp

Revision:

0:f6e68b4ce169

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RTC/ds3231m.cpp	Mon Feb 09 13:40:46 2015 +0000
@@ -0,0 +1,225 @@
+/*
+ * VFD Modular Clock - mbed
+ * (C) 2011-14 Akafugu Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+ *
+ */
+
+#include "global.h"
+#include "ds3231m.h"
+
+#define DS3231M_SLAVE_ADDR 0xD0
+
+DS3231M::DS3231M(I2C& i2c)
+ : RTC()
+ , m_i2c(i2c)
+{
+    m_i2c.frequency(100000);    
+}
+
+void DS3231M::begin()
+{
+}
+
+time_t DS3231M::time()
+{
+    return m_time;
+}
+
+struct tm* DS3231M::getTime()
+{
+    char rtc[7];
+    
+    rtc[0] = 0; // second register, 0
+    int w = m_i2c.write(DS3231M_SLAVE_ADDR, rtc, 1);
+    int r = m_i2c.read(DS3231M_SLAVE_ADDR, rtc, 7);
+    
+    // Clear clock halt bit from read data
+    //rtc[0] &= ~(_BV(CH_BIT));
+    
+    m_tm.tm_sec  = bcd2dec(rtc[0]);
+    m_tm.tm_min  = bcd2dec(rtc[1]);
+    m_tm.tm_hour = bcd2dec(rtc[2]);
+    m_tm.tm_wday = bcd2dec(rtc[3])-1;
+    m_tm.tm_mday = bcd2dec(rtc[4]);
+    m_tm.tm_mon  = bcd2dec(rtc[5])-1; // tm_mon is 0-11
+    m_tm.tm_year = bcd2dec(rtc[6]);
+    
+    return &m_tm;    
+}
+
+void DS3231M::getTime(uint8_t* hour, uint8_t* min, uint8_t* sec)
+{
+    char rtc[3];
+    
+    rtc[0] = 0; // second register, 0
+    int w = m_i2c.write(DS3231M_SLAVE_ADDR, rtc, 1);
+    int r = m_i2c.read(DS3231M_SLAVE_ADDR, rtc, 3);
+    
+    // Clear clock halt bit from read data
+    //rtc[0] &= ~(_BV(CH_BIT));
+    
+    if (sec)  *sec =  bcd2dec(rtc[0]);
+    if (min)  *min =  bcd2dec(rtc[1]);
+    if (hour) *hour = bcd2dec(rtc[2]);
+}
+
+void DS3231M::setTime(time_t t)
+{
+    struct tm * timeinfo;
+    timeinfo = localtime (&t);
+    setTime(timeinfo->tm_hour, timeinfo->tm_min, timeinfo->tm_sec);
+}
+
+void DS3231M::setTime(uint8_t hour, uint8_t min, uint8_t sec)
+{
+    write_byte(dec2bcd(sec), 0);
+    write_byte(dec2bcd(min), 1);
+    write_byte(dec2bcd(hour), 2);
+}
+
+void DS3231M::setTime(struct tm* tm)
+{
+    write_byte(dec2bcd(tm->tm_sec),  0);
+    write_byte(dec2bcd(tm->tm_min),  1);
+    write_byte(dec2bcd(tm->tm_hour), 2);
+    write_byte(dec2bcd(tm->tm_wday+1),  3);
+    write_byte(dec2bcd(tm->tm_mday),  4);
+    write_byte(dec2bcd(tm->tm_mon+1), 5);
+    write_byte(dec2bcd(tm->tm_year),  6);
+}
+
+void DS3231M::setAlarm(time_t t)
+{
+    struct tm * timeinfo;
+    timeinfo = localtime (&t);
+    setAlarm(timeinfo->tm_hour, timeinfo->tm_min, timeinfo->tm_sec);
+}
+
+void DS3231M::setAlarm(uint8_t hour, uint8_t min, uint8_t sec)
+{
+    /*
+     *  07h: A1M1:0  Alarm 1 seconds
+     *  08h: A1M2:0  Alarm 1 minutes
+     *  09h: A1M3:0  Alarm 1 hour (bit6 is am/pm flag in 12h mode)
+     *  0ah: A1M4:1  Alarm 1 day/date (bit6: 1 for day, 0 for date)
+     *  Sets alarm to fire when hour, minute and second matches
+     */
+    write_byte(dec2bcd(sec), 0x07); // second
+    write_byte(dec2bcd(min), 0x08); // minute
+    write_byte(dec2bcd(hour), 0x09); // hour
+    write_byte(0x81, 0x0a); // day (upper bit must be set)
+    
+    // clear alarm flag
+    uint8_t val = read_byte(0x0f);
+    write_byte(val & ~0x01, 0x0f);
+}
+
+
+struct tm* DS3231M::getAlarm(void)
+{
+    struct tm * timeinfo = getTime();
+    uint8_t hour, min, sec;
+    
+    getAlarm(&hour, &min, &sec);
+    timeinfo->tm_hour = hour;
+    timeinfo->tm_min = min;
+    timeinfo->tm_sec = sec;
+    return timeinfo;
+}
+
+void DS3231M::getAlarm(uint8_t* hour, uint8_t* min, uint8_t* sec)
+{
+    *sec  = bcd2dec(read_byte(0x07) & ~0x80);
+    *min  = bcd2dec(read_byte(0x08) & ~0x80);
+    *hour = bcd2dec(read_byte(0x09) & ~0x80);
+}
+
+bool DS3231M::checkAlarm(void)
+{
+    // Alarm 1 flag (A1F) in bit 0
+    uint8_t val = read_byte(0x0f);
+
+    // clear flag when set
+    if (val & 1)
+        write_byte(val & ~0x01, 0x0f);
+        
+    return val & 1 ? 1 : 0;
+}
+
+void DS3231M::SQWEnable(bool enable)
+{
+    uint8_t control = read_byte(0x0E);  // read control register
+    if (enable) {
+        control |=  0x40; // set BBSQW to 1
+        control &= ~0x04; // set INTCN to 0
+    }
+    else {
+        control &= ~0x40; // set BBSQW to 0
+    }
+    // write control back
+    write_byte(control, 0x0E);
+}
+
+void DS3231M::SQWSetFreq(enum RTC_SQW_FREQ freq)
+{
+    uint8_t control = read_byte(0x0E);  // read control register
+    control &= ~0x18; // Set to 0
+    control |= (freq << 4); // Set freq bitmask
+
+    // write control back
+    write_byte(control, 0x0E);
+}
+
+void DS3231M::Osc32kHzEnable(bool enable)
+{
+    uint8_t status = read_byte(0x0F);  // read status
+
+    if (enable)
+        status |= 0x08; // set to 1
+    else
+        status &= ~0x08; // Set to 0
+
+    // write status back
+    write_byte(status, 0x0F);
+}
+
+uint8_t DS3231M::read_byte(uint8_t offset)
+{
+    char buf[1];
+    buf[0] = offset;
+    
+    int w = m_i2c.write(DS3231M_SLAVE_ADDR, buf, 1);
+    int r = m_i2c.read(DS3231M_SLAVE_ADDR,  buf, 1);    
+    //error = ((w!=0) || (r!=0));
+    
+    return buf[0];
+}
+
+void DS3231M::write_byte(uint8_t b, uint8_t offset)
+{
+    char buf[2];
+    buf[0] = offset;
+    buf[1] = b;
+    
+    int w = m_i2c.write(DS3231M_SLAVE_ADDR, buf, 2); 
+    //error=(w!=0);   
+}
+
+void DS3231M::write_addr(uint8_t addr)
+{
+    /*
+    Wire.beginTransmission(RTC_ADDR);
+    Wire.write(addr);
+    Wire.endTransmission();
+    */
+}
+