RTC_NXP_Arduino

RTC device operation sample code for Arduino

Note This library works with I2C_device library together. Please be sure the I2C_device library is imported in your environment before trying to build.

PCF2131-ARD, PCF85063TP-ARD, PCF85063AT-ARD and PCF85263ATL-ARD : Arduino® Shield Evaluation Board for RTCs

What is this?

An Arduino library for RTC devices with its sample code.
A method of time() in each RTC device classes are cpmpatible to time() function in 'time.h'. The method is defined as same as time_t time( time_t* tp ).
It returns a value in the systems time stamp format of 'time.h'.

To display the calendar/time, it can be written in this way.

#include <PCF2131_I2C.h>  // including PCF2131_I2C class
#include <time.h>

PCF2131_I2C rtc;
...
..
current_time = rtc.time( NULL );
Serial.println( ctime( &current_time ) );  // Result will appear like -> "Sun Apr 09 07:11:37 2023"

Supported devices

PCF2131, PCF85063A, PCF85063TP and PCF85263A are supported.
On PCF2131, both I²C and SPI can be used for interfacing MCU. Include device name header file (PCF85063A.h, PCF85063TP.h, PCF85063TP.h and for PCF2131, PCF2131_I2C.h, PCF2131_SPI.h) to use those class libraries.

Type#	Header file	Features	Interface	Evaluation board
PCF2131	`PCF2131_I2C.h` `PCF2131_SPI.h`	Nano-Power Highly Accurate RTC with Integrated Quartz Crystal	I²C and SPI	PCF2131/PCA2131 Arduino® Shield Evaluation Board
PCF85053A	`PCF85053A.h`	Bootable CPU RTC with Two I2C Buses, 128 Byte SRAM and Alarm Function	I²C	PCF85053ATK-ARD – PCF85053ATK Evaluation Board
PCF85063A	`PCF85063A.h`	Tiny Real-Time Clock/Calendar with Alarm Function	I²C	PCF85063AT-ARD Arduino® Shield Evaluation Board
PCF85063TP	`PCF85063TP.h`	Tiny Real-Time Clock/Calendar	I²C	PCF85063TP-ARD Arduino® Shield Evaluation Board
PCF85263A	`PCF85263A.h`	Tiny Real-Time Clock/Calendar with Alarm Function, Battery Switch-Over, Time Stamp Input	I²C	PCF85263ATL-ARD Arduino® Shield Evaluation Board

Code sample

// Very simple sample to use the 'PCF2131-ARD : Arduino® Shield Evaluation Board'

#include <PCF2131_I2C.h>
#include <time.h>

void set_time(void);

PCF2131_I2C rtc;

void setup() {
  Serial.begin(9600);
  Serial.println("\n***** Hello, PCF2131! (I2C interface)*****");

  Wire.begin();

  if (rtc.oscillator_stop()) {
    Serial.println("==== oscillator_stop detected :( ====");
    set_time();
  } else {
    Serial.println("---- RTC has beeing kept running! :) ----");
  }
}

void loop() {
  time_t current_time = 0;

  current_time = rtc.time(NULL);
  Serial.print("time : ");
  Serial.print(current_time);
  Serial.print(", ");
  Serial.println(ctime(&current_time));

  delay(1000);
}
...
..

Getting started

Use Library manager in Arduino IDE for easy install

What's inside?

Examples

Examples are provided as scketch files.

How to use?

After library install, Choose menu on Arduino-IDE: File→Examples→RTC_NXP_Arduino→ sketch for your try

List of sample code

Sketch	Target	Feature
PCF2131_simple_I2C	PCF2131	Simple sample for just getting current time via I²C in every second
PCF2131_simple_SPI	PCF2131	Simple sample for just getting current time via SPI in every second
PCF2131_interrupt_based_operation	PCF2131	Interrupt based operation: Demonstrates second/minute, alarm and timestamp features. IMPORTANT: On the PCF2131-ARD shield board, short D8<-->D2 and D9<-->D3 pins
PCF85053A_simple	PCF85053A	Simple sample for just getting current time in every second
PCF85053A_interrupt_based_operation	PCF85053A	Interrupt based operation: Demonstrates alarm feature
PCF85063A_simple	PCF85063A	Simple sample for just getting current time in every second
PCF85063A_interrupt_based_operation	PCF85063A	Interrupt based operation: Demonstrates timer and alarm features
PCF85063TP	PCF85063TP	Simple sample for just getting current time in every second
PCF85263A_simple	PCF85263A	Simple sample for just getting current time in every second
PCF85263A_interrupt_based_operation	PCF85263A	Interrupt based operation: Demonstrates using 2 interrupt lines
PCF85263A_timestamp	PCF85263A	Timestamp operation: Demonstrates timestamp feature

TIPS

If you need to use different I²C bus on Arduino, it can be done like this. This sample shows how the Wire1 on Arduino Due can be operated.

include <PCF2131_I2C.h>

PCF2131_I2C rtc(Wire1);

void setup() {
  Wire1.begin();

Document

For details of the library, please find descriptions in this document.

References

Related libraries

Library	Feature	Target devices	Required library
GPIO_NXP_Arduino	GPIO libraries	PCAL6408A, PCAL6416A, PCAL6524, PCAL6534, PCA9555, PCA9554	I2C_device_Arduino
LCDDriver_NXP_Arduino	LCD driver libraries	PCA8561	I2C_device_Arduino
LEDDriver_NXP_Arduino	LED driver libraries	PCA9955B, PCA9956B, PCA9957	I2C_device_Arduino
MUX_SW_NXP_Arduino	I²C mux/switch libraries	PCA9846	I2C_device_Arduino
RTC_NXP_Arduino	RTC libraries	PCF2131, PCF85053A, PCF85063A, PCF85063TP, PCF85263A	I2C_device_Arduino
TempSensor_NXP_Arduino	Temperature sensor libraries	LM75B, P3T1084, P3T1085, P3T1035, P3T2030, PCT2075	I2C_device_Arduino
I2C_device_Arduino	Base library for I²C operations	none (can be applied as base class for all I²C targets)	---

teddokano/RTC_NXP_Arduino