RTC Pi Node JS Library

Node.js Library to use with RTC Pi Raspberry Pi real-time clock board.

Install

To download to your Raspberry Pi type in the terminal:

git clone https://github.com/abelectronicsuk/ABElectronics_NodeJS_Libraries.git

The RTC Pi library is located in the /lib/rtcpi/ directory

The example files are located in the /examples/rtcpi/ directory

The RTC Pi library requires the i2c-bus library to run.

Install from npm package repositoryi2c-bus with

npm install i2c-bus

Functions:

setDate(date) 

Set the date and time on the RTC using a javascript Date object
Parameter: date
Returns: null

readDate() 

Returns the date from the RTC as a javascript Date object
Returns: date object

enableOutput() 

Enable the square-wave output on the SQW pin.
Returns: null

disableOutput()

Disable the square-wave output on the SQW pin.
Returns: null

setFrequency(frequency)

Set the frequency for the square-wave output on the SQW pin.
Parameter: frequency - options are: 1 = 1Hz, 2 = 4.096KHz, 3 = 8.192KHz, 4 = 32.768KHz
Returns: null

writeMemory(address, valuearray)

Write to the memory on the DS1307. The DS1307 contains 56 - Byte, battery-backed RAM with Unlimited Writes
Parameter: address - 0x08 to 0x3F
Parameter: valuearray - byte array (Uint8Array) containing data to be written to memory
Returns: null

readMemory(address, valuearray)

Read from the memory on the DS1307. The DS1307 contains 56 - Byte, battery-backed RAM with Unlimited Writes
Parameter: address - 0x08 to 0x3F
Parameter: length - Up to 32 bytes. length can not exceed the available address space.
Returns: Returns a Uint8Array type array of the data read from memory

Usage

To use the RTC Pi library in your code you must first import the library:

var rtcpi = require('../../lib/rtcpi/rtcpi');

Next, you must create an RTCPi object:

var rtc = new RTCPi();

Set the current time using a date object:

var d = new Date(2016, 07, 04, 10, 23, 00, 00);
rtc.setDate(d);

Enable the square-wave output at 8.192KHz on the SQW pin:

rtc.set_frequency(3)
rtc.enable_output()

Read the current date and time from the RTC at 1-second intervals:

var myClock = setInterval(clockTimer, 1000);

function clockTimer() {    
    console.log(rtc.readDate().toISOString());
}