Remarks

Ds1307
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

The DS1307 is a low-power realtime clock (RTC) controlled via I2C.

Code Example

Ds1307 rtc;

public override Task Initialize()
{
    Resolver.Log.Info("Initializing...");

    rtc = new Ds1307(Device.CreateI2cBus());

    return base.Initialize();
}

public override Task Run()
{
    var dateTime = new DateTime();
    var running = rtc.IsRunning;

    Resolver.Log.Info($"{(running ? "is running" : "is not running")}");

    if (!running)
    {
        Resolver.Log.Info(" Starting RTC...");
        rtc.IsRunning = true;
    }

    dateTime = rtc.GetTime();
    Resolver.Log.Info($" RTC current time is: {dateTime.ToString("MM/dd/yy HH:mm:ss")}");

    Resolver.Log.Info($" Setting RTC to : {dateTime.ToString("MM/dd/yy HH:mm:ss")}");
    dateTime = new DateTime(2030, 2, 15);
    rtc.SetTime(dateTime);

    dateTime = rtc.GetTime();
    Resolver.Log.Info($" RTC current time is: {dateTime.ToString("MM/dd/yy HH:mm:ss")}");

    var rand = new Random();

    var data = new byte[56];

    for (int i = 0; i < 56; i++)
    {
        data[i] = (byte)rand.Next(256);
    }

    Resolver.Log.Info($" Writing to RTC RAM   : {BitConverter.ToString(data)}");
    rtc.WriteRAM(0, data);
    Resolver.Log.Info($" Reading from RTC RAM : ");
    data = rtc.ReadRAM(0, 56);
    Resolver.Log.Info(BitConverter.ToString(data));

    return base.Run();
}

Sample project(s) available on GitHub

Wiring Example

The DS3231 real time clock module (see image below) requires only four (for simple timekeeping) or five (for alarms) connections

DS3231	Meadow Pin
GND	GND
VCC	3V3
SCL	D08 (SCL Pin)
SDA	D07 (SDA Pin)

The 32K pin outputs the 32,768 Hz clock signal from the module. This signal is only available when power is supplied by V_cc, it is not available when the module is on battery power.

Characteristic	Locus
Inheritance	System.Object > Ds1307
Namespace	Meadow.Foundation.RTCs
Assembly	Ds1307.dll

Syntax

public class Ds1307 : object

Constructors

Ds1307(II2cBus)

Create a new Ds1307 object

Declaration

public Ds1307(II2cBus i2cBus)

Parameters

Type	Name	Description
II2cBus	i2cBus	The I2C bus

Properties

IsRunning

Stops or starts the clock oscillator Stopping the oscillator decreases power consumption (and stops the clock)

Declaration

public bool IsRunning { get; set; }

Property Value

Type	Description
System.Boolean

Methods

GetTime()

Get the time from the real-time clock

Declaration

public DateTime GetTime()

Returns

Type	Description
DateTime

ReadRAM(Int32, Int32)

The DS1307 has 56 bytes of battery-backed RAM. Use this method to Read from that memory.

Declaration

public byte[] ReadRAM(int offset, int count)

Parameters

Type	Name	Description
System.Int32	offset	Offset to the start of the read (0-55)
System.Int32	count	The number of bytes to read

Returns

Type	Description
System.Byte[]

SetTime(DateTime)

Set the time on the real-time clock

Declaration

public void SetTime(DateTime time)

Parameters

Type	Name	Description
DateTime	time	The new time

SquareWaveOutput(Ds1307.SquareWaveFrequency)

Square wave output

Declaration

public void SquareWaveOutput(Ds1307.SquareWaveFrequency freq)

Parameters

Type	Name	Description
Ds1307.SquareWaveFrequency	freq	The frequency

WriteRAM(Int32, Byte[])

The DS1307 has 56 bytes of battery-backed RAM Use this method to Write to that memory

Declaration

public void WriteRAM(int offset, params byte[] data)

Parameters

Type	Name	Description
System.Int32	offset
System.Byte[]	data