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Enable other wire instances #74

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149cfe0
Support for additional Wire ports
rw-schumann May 3, 2025
c249f60
Enable use of other TwoWire devices
rw-schumann May 3, 2025
063772b
Fixed default initialization
rw-schumann May 3, 2025
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138 changes: 77 additions & 61 deletions src/MCP7940.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,6 @@ Arduino Library for the MCP7940M and MCP7940N Real-Time Clock devices\n\n
See main library header file for details
*/
#include "MCP7940.h"

/*! Define the number of days in each month */
const uint8_t daysInMonth[] PROGMEM = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
static uint16_t date2days(uint16_t y, uint8_t m, uint8_t d) {
Expand All @@ -16,7 +15,9 @@ static uint16_t date2days(uint16_t y, uint8_t m, uint8_t d) {
* @param[in] d Day
* @return number of days from a given Y M D value
*/
if (y >= 2000) { y -= 2000; } // of if-then year is greater than 2000
if (y >= 2000) {
y -= 2000;
} // of if-then year is greater than 2000
uint16_t days = d;
for (uint8_t i = 1; i < m; ++i) // Add number of days for each month
{
Expand Down Expand Up @@ -50,7 +51,9 @@ static uint8_t conv2d(const char* p) {
* @return decimal value
*/
uint8_t v = 0;
if ('0' <= *p && *p <= '9') { v = *p - '0'; } // of if-then character in range
if ('0' <= *p && *p <= '9') {
v = *p - '0';
} // of if-then character in range
return 10 * v + *++p - '0';
} // of method conv2d
DateTime::DateTime(uint32_t t) {
Expand All @@ -60,16 +63,12 @@ DateTime::DateTime(uint32_t t) {
constructor so there are multiple definitions. This implementation ignores time zones and DST
changes. It also ignores leap seconds, see http://en.wikipedia.org/wiki/Leap_second
@param[in] t seconds since the year 1970 (UNIX timet) */
if (t < SECS_1970_TO_2000) {
t = 0; // set to lowest possible date 2000-01-01
} else {
t -= SECS_1970_TO_2000; // bring to 2000 timestamp from 1970
}
t -= SECS_1970_TO_2000; // bring to 2000 timestamp from 1970
ss = t % 60;
t /= 60;
mm = t % 60;
t /= 60;
hh = t % 24;
hh = t % 24;
uint16_t days = t / 24;
uint8_t leap;
for (yOff = 0;; ++yOff) {
Expand Down Expand Up @@ -98,7 +97,9 @@ DateTime::DateTime(uint16_t year, uint8_t month, uint8_t day, uint8_t hour, uint
@param[in] hour Hour
@param[in] min Minute
@param[in] sec Second */
if (year >= 2000) { year -= 2000; } // of if-then year is greater than 2000 for offset
if (year >= 2000) {
year -= 2000;
} // of if-then year is greater than 2000 for offset
yOff = year;
m = month;
d = day;
Expand All @@ -125,14 +126,30 @@ DateTime::DateTime(const char* date, const char* time) {
@param[in] time Pointer to time string */
yOff = conv2d(date + 9);
switch (date[0]) {
case 'J': m = (date[1] == 'a') ? 1 : ((date[2] == 'n') ? 6 : 7); break; // Jan June July
case 'F': m = 2; break; // February
case 'A': m = date[2] == 'r' ? 4 : 8; break; // April August
case 'M': m = date[2] == 'r' ? 3 : 5; break; // March May
case 'S': m = 9; break; // September
case 'O': m = 10; break; // October
case 'N': m = 11; break; // November
case 'D': m = 12; break; // December
case 'J':
m = (date[1] == 'a') ? 1 : ((date[2] == 'n') ? 6 : 7);
break; // Jan June July
case 'F':
m = 2;
break; // February
case 'A':
m = date[2] == 'r' ? 4 : 8;
break; // April August
case 'M':
m = date[2] == 'r' ? 3 : 5;
break; // March May
case 'S':
m = 9;
break; // September
case 'O':
m = 10;
break; // October
case 'N':
m = 11;
break; // November
case 'D':
m = 12;
break; // December
} // of switch for the month
d = conv2d(date + 4); // Compute the day
hh = conv2d(time);
Expand Down Expand Up @@ -174,7 +191,7 @@ uint32_t DateTime::unixtime(void) const {
*/
uint16_t days = date2days(yOff, m, d); // Compute days
uint32_t t = time2long(days, hh, mm, ss); // Compute seconds
t += SECS_1970_TO_2000; // Add time from 1970 to 2000
t += SECS_1970_TO_2000; // Add time form 1970 to 2000
return t;
} // of method unixtime()
long DateTime::secondstime(void) const {
Expand All @@ -186,14 +203,6 @@ long DateTime::secondstime(void) const {
long t = time2long(days, hh, mm, ss);
return t;
} // of method secondstime()
bool DateTime::equals(const DateTime* other) {
/*!
@brief added equals method for class DateTime
@return true if date and time are equal else return false
*/
return (this->yOff == other->yOff && this->m == other->m && this->d == other->d &&
this->hh == other->hh && this->mm == other->mm && this->ss == other->ss);
}
DateTime DateTime::operator+(const TimeSpan& span) {
/*!
@brief overloaded "+" operator for class DateTime
Expand Down Expand Up @@ -228,35 +237,28 @@ TimeSpan TimeSpan::operator+(const TimeSpan& right) {
TimeSpan TimeSpan::operator-(const TimeSpan& right) {
return TimeSpan(_seconds - right._seconds);
} // of overloaded subtract
bool MCP7940_Class::begin(const uint32_t i2cSpeed) const {


/***************************************************************************************************
** **
** Implementation of MCP7940 **
** **
***************************************************************************************************/
//void MCP7940_Class::setWire(TwoWire& wirePort) {_mcpWire = &wirePort;}
bool MCP7940_Class::begin(bool initWire, const uint32_t i2cSpeed) const {
/*!
@brief Start I2C device communications
@details Starts I2C comms with the device, using a default speed if one is not specified
@param[in] initWire defaults to TRUE, allows sharing of the i2c line and initialization elsewhere
@param[in] i2cSpeed defaults to I2C_STANDARD_MODE, otherwise use speed in Herz
@return true if successfully started communication, otherwise false
*/
return begin(SDA, SCL, i2cSpeed);
} // of method begin()
bool MCP7940_Class::begin(const uint8_t sda, const uint8_t scl, const uint32_t i2cSpeed) const {
/*!
@brief Start I2C device communications
@details Starts I2C comms with the device, using default SDA and SCL ports as well as speed
if they are not specified
@param[in] sda defaults to PIN_WIRE_SDA, otherwise use pin (ignored if not ESP8266)
@param[in] scl defaults to PIN_WIRE_SCL, otherwise use pin (ignored if not ESP8266)
@param[in] i2cSpeed defaults to I2C_STANDARD_MODE, otherwise use speed in Herz
@return true if successfully started communication, otherwise false
*/
#if defined(ESP8266)
Wire.begin(sda, scl); // Start I2C as master device using the specified SDA and SCL
#else
Wire.begin(); // Start I2C as master device
#endif
(void)sda; // force compiler to ignore this potentially unused parameter
(void)scl; // force compiler to ignore this potentially unused parameter
Wire.setClock(i2cSpeed); // Set the I2C bus speed
Wire.beginTransmission(MCP7940_ADDRESS); // Address the MCP7940
if (Wire.endTransmission() == 0) // If there a device present
if (initWire) {
_mcpWire->begin(); // Start I2C as master device
_mcpWire->setClock(i2cSpeed); // Set the I2C bus speed
}
_mcpWire->beginTransmission(MCP7940_ADDRESS); // Address the MCP7940
if (_mcpWire->endTransmission() == 0) // If there a device present
{
clearRegisterBit(MCP7940_RTCHOUR, MCP7940_12_24); // Use 24 hour clock
setRegisterBit(MCP7940_CONTROL, MCP7940_ALMPOL); // assert alarm low, default high
Expand All @@ -265,7 +267,6 @@ bool MCP7940_Class::begin(const uint8_t sda, const uint8_t scl, const uint32_t i
return false; // return error if no device found
} // of if-then-else device detected
} // of method begin()

uint8_t MCP7940_Class::readByte(const uint8_t addr) const {
/*!
@brief Read a single byte from the device address
Expand Down Expand Up @@ -437,11 +438,10 @@ void MCP7940_Class::adjust(const DateTime& dt) {
I2C_write(MCP7940_RTCMIN, int2bcd(dt.minute()));
I2C_write(MCP7940_RTCHOUR, int2bcd(dt.hour()));
weekdayWrite(dt.dayOfTheWeek()); // Update the weekday
I2C_write(MCP7940_RTCMTH, int2bcd(dt.month())); // Month, ignore R/O leapyear bit
I2C_write(MCP7940_RTCDATE, int2bcd(dt.day())); // Write the day of month
I2C_write(MCP7940_RTCMTH, int2bcd(dt.month())); // Month, ignore R/O leapyear bit
I2C_write(MCP7940_RTCYEAR, int2bcd(dt.year() - 2000)); // Write the year
deviceStart(); // Restart the oscillator
weekdayWrite(dt.dayOfTheWeek()); // Silicon errata issue 4
_SetUnixTime = dt.unixtime(); // Store time of last change
} // of method adjust
uint8_t MCP7940_Class::weekdayRead() const {
Expand Down Expand Up @@ -536,10 +536,18 @@ int8_t MCP7940_Class::calibrate(const float fMeas) const {
uint32_t fIdeal = getSQWSpeed(); // read the current SQW Speed code
switch (fIdeal) // set variable to real SQW speed
{
case 0: fIdeal = 1; break;
case 1: fIdeal = 4096; break;
case 2: fIdeal = 8192; break;
case 4: fIdeal = 64; break;
case 0:
fIdeal = 1;
break;
case 1:
fIdeal = 4096;
break;
case 2:
fIdeal = 8192;
break;
case 4:
fIdeal = 64;
break;
case 3:
fIdeal = 32768;
trim = 0; // Trim is ignored on 32KHz signal
Expand Down Expand Up @@ -745,7 +753,9 @@ bool MCP7940_Class::clearAlarm(const uint8_t alarmNumber) const {
@param[in] alarmNumber Alarm number 0 or 1
@return False if the alarmNumber is out of range, otherwise true
*/
if (alarmNumber > 1) { return false; } // of if-then a bad alarm number
if (alarmNumber > 1) {
return false;
} // of if-then a bad alarm number
clearRegisterBit(alarmNumber ? MCP7940_ALM1WKDAY : MCP7940_ALM0WKDAY,
MCP7940_ALM0IF); // reset register bit
return true;
Expand All @@ -757,7 +767,9 @@ bool MCP7940_Class::setAlarmState(const uint8_t alarmNumber, const bool state) c
@param[in] state State to the set the alarm to
@return False if the alarmNumber is out of range, otherwise true
*/
if (alarmNumber > 1) { return false; } // of if-then a bad alarm number
if (alarmNumber > 1) {
return false;
} // of if-then a bad alarm number
writeRegisterBit(MCP7940_CONTROL, alarmNumber ? MCP7940_ALM1EN : MCP7940_ALM0EN,
state); // Overwrite register bit
return true;
Expand All @@ -768,7 +780,9 @@ bool MCP7940_Class::getAlarmState(const uint8_t alarmNumber) const {
@param[in] alarmNumber Alarm number 0 or 1
@return False if the alarmNumber is out of range or off, otherwise true
*/
if (alarmNumber > 1) { return false; } // of if-then a bad alarm number
if (alarmNumber > 1) {
return false;
} // of if-then a bad alarm number
return readRegisterBit(MCP7940_CONTROL,
alarmNumber ? MCP7940_ALM1EN : MCP7940_ALM0EN); // Get state of alarm
} // of getAlarmState()
Expand All @@ -778,7 +792,9 @@ bool MCP7940_Class::isAlarm(const uint8_t alarmNumber) const {
@param[in] alarmNumber Alarm number 0 or 1
@return False if the alarmNumber is out of range or off, otherwise true
*/
if (alarmNumber > 1) { return false; } // of if-then a bad alarm number
if (alarmNumber > 1) {
return false;
} // of if-then a bad alarm number
return readRegisterBit(alarmNumber ? MCP7940_ALM1WKDAY : MCP7940_ALM0WKDAY,
MCP7940_ALM0IF); // Get alarm state
} // of method isAlarm()
Expand Down
62 changes: 32 additions & 30 deletions src/MCP7940.h
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Original file line number Diff line number Diff line change
Expand Up @@ -254,11 +254,12 @@ class MCP7940_Class {
@brief Main class definition with forward declarations
*/
public:
MCP7940_Class(){}; ///< Unused Class constructor
MCP7940_Class(TwoWire &wirePort = Wire): _mcpWire(&wirePort) {}; // Default is Wire so should be backwards compatible
~MCP7940_Class(){}; ///< Unused Class destructor
bool begin(const uint32_t i2cSpeed) const;
bool begin(const uint8_t sda = SDA, const uint8_t scl = SCL,
const uint32_t i2cSpeed = I2C_STANDARD_MODE) const;
bool begin(bool initWire = true, const uint32_t i2cSpeed = 100000) const;
// bool begin(const uint8_t sda = SDA, const uint8_t scl = SCL,
// const uint32_t i2cSpeed = I2C_STANDARD_MODE) const;
void setWire(TwoWire &wirePort) {_mcpWire = &wirePort;};
bool deviceStatus() const;
bool deviceStart() const;
bool deviceStop() const;
Expand Down Expand Up @@ -338,13 +339,13 @@ class MCP7940_Class {
@return Pointer to return data structure
*/
uint8_t i{0}; // return number of bytes read
Wire.beginTransmission(MCP7940_EUI_ADDRESS); // Address the special I2C address
Wire.write((addr % 8) + MCP7940_EUI_RAM_ADDRESS); // Send register address to read from
if (Wire.endTransmission() == 0) { // Close transmission and check error code
Wire.requestFrom(MCP7940_EUI_ADDRESS, sizeof(T)); // Request a block of data, max 61 bits
_mcpWire->beginTransmission(MCP7940_EUI_ADDRESS); // Address the special I2C address
_mcpWire->write((addr % 8) + MCP7940_EUI_RAM_ADDRESS); // Send register address to read from
if (_mcpWire->endTransmission() == 0) { // Close transmission and check error code
_mcpWire->requestFrom(MCP7940_EUI_ADDRESS, sizeof(T)); // Request a block of data, max 61 bits
uint8_t* bytePtr = (uint8_t*)&value; // Declare pointer to start of structure
for (i = 0; i < sizeof(T); i++) { // Loop for each byte to be read
*bytePtr++ = Wire.read(); // Read a byte
*bytePtr++ = _mcpWire->read(); // Read a byte
} // of for-next each byte
} // if-then success
return i; // return number of bytes read
Expand All @@ -361,23 +362,24 @@ class MCP7940_Class {
@return Pointer to data structure to write
*/
uint8_t i{0}; // return number of bytes read
Wire.beginTransmission(MCP7940_EUI_ADDRESS); // Address the special I2C address
Wire.write(MCP7940_EEUNLOCK); // Send special register address to write to
Wire.write(0x55); // Special write value to start unlock
i = Wire.endTransmission(); // close transmission of first byte
Wire.beginTransmission(MCP7940_EUI_ADDRESS); // Address the special I2C address
Wire.write(MCP7940_EEUNLOCK); // Send special register address to write to
Wire.write(0x55); // Special write value to complete unlock
i = Wire.endTransmission(); // close transmission of second byte
Wire.beginTransmission(MCP7940_EUI_ADDRESS); // Address the special I2C address
Wire.write((addr % 8) + MCP7940_EUI_RAM_ADDRESS); // Send register address to read from
Wire.write((uint8_t*)&value, sizeof(T)); // write the data
i = Wire.endTransmission(); // close transmission of actual write
_mcpWire->beginTransmission(MCP7940_EUI_ADDRESS); // Address the special I2C address
_mcpWire->write(MCP7940_EEUNLOCK); // Send special register address to write to
_mcpWire->write(0x55); // Special write value to start unlock
i = _mcpWire->endTransmission(); // close transmission of first byte
_mcpWire->beginTransmission(MCP7940_EUI_ADDRESS); // Address the special I2C address
_mcpWire->write(MCP7940_EEUNLOCK); // Send special register address to write to
_mcpWire->write(0x55); // Special write value to complete unlock
i = _mcpWire->endTransmission(); // close transmission of second byte
_mcpWire->beginTransmission(MCP7940_EUI_ADDRESS); // Address the special I2C address
_mcpWire->write((addr % 8) + MCP7940_EUI_RAM_ADDRESS); // Send register address to read from
_mcpWire->write((uint8_t*)&value, sizeof(T)); // write the data
i = _mcpWire->endTransmission(); // close transmission of actual write
if (i == 0) i = sizeof(T); // return number of bytes on success
return i; // return number of bytes read
} // of method writeEUI()

private:
TwoWire *_mcpWire = &Wire;
uint32_t _SetUnixTime{0}; ///< UNIX time when clock last set
/*************************************************************************************************
** Template functions definitions are done in the header file **
Expand All @@ -399,13 +401,13 @@ class MCP7940_Class {
@return number of bytes read
*/
uint8_t i{0}; // return number of bytes read
Wire.beginTransmission(MCP7940_ADDRESS); // Address the I2C device
Wire.write(address); // Send register address to read from
if (Wire.endTransmission() == 0) { // Close transmission and check error code
Wire.requestFrom(MCP7940_ADDRESS, sizeof(T)); // Request a block of data
_mcpWire->beginTransmission(MCP7940_ADDRESS); // Address the I2C device
_mcpWire->write(address); // Send register address to read from
if (_mcpWire->endTransmission() == 0) { // Close transmission and check error code
_mcpWire->requestFrom(MCP7940_ADDRESS, sizeof(T)); // Request a block of data
uint8_t* bytePtr = (uint8_t*)&value; // Declare pointer to start of structure
for (i = 0; i < sizeof(T); i++) { // Loop for each byte to be read
*bytePtr++ = Wire.read(); // Read a byte
*bytePtr++ = _mcpWire->read(); // Read a byte
} // of for-next each byte
} // if-then success
return i; // return number of bytes read
Expand All @@ -421,10 +423,10 @@ class MCP7940_Class {
@param[in] value Data Type "T" to write
@return number of bytes written
*/
Wire.beginTransmission(MCP7940_ADDRESS); // Address the I2C device
Wire.write(address); // Send register address to read from
Wire.write((uint8_t*)&value, sizeof(T)); // write the data
uint8_t i = Wire.endTransmission(); // close transmission and save status
_mcpWire->beginTransmission(MCP7940_ADDRESS); // Address the I2C device
_mcpWire->write(address); // Send register address to read from
_mcpWire->write((uint8_t*)&value, sizeof(T)); // write the data
uint8_t i = _mcpWire->endTransmission(); // close transmission and save status
if (i == 0) i = sizeof(T); // return number of bytes on success
return i; // return the number of bytes written
} // end of template method "I2C_write()"
Expand Down