Remarks

At24Cxx
Status Status badge: working
Source code GitHub
Datasheet(s) GitHub
NuGet package NuGet Gallery for Meadow.Foundation.ICs.EEPROM.At24Cxx

The AT24Cxx series of chips provide a mechanism for storing data that will survive a power outage or battery failure. These EEPROMs are available in varying sizes and are accessible using the I2C interface.

Purchasing

Code Example

At24Cxx eeprom;

public override Task Initialize()
{
    Console.WriteLine("Initialize...");

    //256kbit = 256*1024 bits = 262144 bits = 262144 / 8 bytes = 32768 bytes
    //if you're using the ZS-042 board, it has an AT24C32 and uses the default value of 8192
    eeprom = new At24Cxx(i2cBus: Device.CreateI2cBus(), memorySize: 32768);

    return base.Initialize();
}

public override Task Run()
{
    Console.WriteLine("Write to eeprom");
    eeprom.Write(0, new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 });

    Console.WriteLine("Read from eeprom");
    var memory = eeprom.Read(0, 16);

    for (ushort index = 0; index < 16; index++)
    {
        Thread.Sleep(50);
        Console.WriteLine("Byte: " + index + ", Value: " + memory[index]);
    }

    eeprom.Write(3, new byte[] { 10 });
    eeprom.Write(7, new byte[] { 1, 2, 3, 4 });
    memory = eeprom.Read(0, 16);

    for (ushort index = 0; index < 16; index++)
    {
        Thread.Sleep(50);
        Console.WriteLine("Byte: " + index + ", Value: " + memory[index]);
    }

    return base.Run();
}

Sample project(s) available on GitHub

Wiring Example

To wire a At24Cxx to your Meadow board, connect the following:

At24Cxx Meadow Pin
GND GND
SCL D08 (SCL)
SDA D07 (SDA)
VCC 3V3

It should look like the following diagram:

Characteristic Locus
Inheritance System.Object > At24Cxx
Namespace Meadow.Foundation.ICs.EEPROM
Assembly At24Cxx.dll

Syntax

public class At24Cxx : object

Constructors

At24Cxx(II2cBus, Byte, UInt16, UInt16)

Create a new AT24Cxx object using the default parameters for the component.

Declaration
public At24Cxx(II2cBus i2cBus, byte address = null, ushort pageSize = null, ushort memorySize = null)

Parameters

Type Name Description
II2cBus i2cBus

I2CBus connected to display

System.Byte address

Address of the At24Cxx (default = 0x50).

System.UInt16 pageSize

Number of bytes in a page (default = 32 - AT24C32).

System.UInt16 memorySize

Total number of bytes in the EEPROM (default = 8192 - AT24C32).

Properties

MemorySize

Number of bytes in the EEPROM module.

Declaration
public ushort MemorySize { get; }

Property Value

Type Description
System.UInt16

PageSize

Number of bytes in a page.

Declaration
public ushort PageSize { get; }

Property Value

Type Description
System.UInt16

Methods

Read(UInt16, UInt16)

Force the sensor to make a reading and update the relevant properties.

Declaration
public byte[] Read(ushort startAddress, ushort amount)

Parameters

Type Name Description
System.UInt16 startAddress

Start address for the read operation.

System.UInt16 amount

Amount of data to read from the EEPROM.

Returns

Type Description
System.Byte[]

Write(UInt16, Byte[])

Write a number of bytes to the EEPROM.

Declaration
public void Write(ushort startAddress, params byte[] data)

Parameters

Type Name Description
System.UInt16 startAddress

Address of he first byte to be written.

System.Byte[] data

Data to be written to the EEPROM.