NAME

    Device::I2C - Control and read hardware devices with i2c(SMBus)

VERSION

    version 0.06

SYNOPSIS

       use Device::I2C;
       use Fcntl;
       $dev = Device::I2C->new('/dev/i2c-1', O_RDWR);
       $dev->checkDevice(0x4c);
       print $dev->readByteData(0x20);

DESCRIPTION

    This is a perl interface to I2C interface using libi2c-dev library.

    Prerequisites:

    For Debian and derivative distros(including raspbian) use the following
    to install dependencies:

      sudo apt-get install libi2c-dev i2c-tools build-essential

    If you are using Angstrom Linux use the following:

      opkg install i2c-tools
      opkg install i2c-tools-dev

    For ArchLINUX use the following steps:

      pacman -S base-devel
      pacman -S i2c-tools

    Special Instructions for enabling the I2C driver on a Raspberry Pi:

    You will need to comment out the driver from the blacklist. currently
    the I2C driver isn't being loaded.

         sudo vim /etc/modprobe.d/raspi-blacklist.conf

    Replace this line

         blacklist i2c-bcm2708

    with this

         #blacklist i2c-bcm2708

    You now need to edit the modules conf file.

         sudo vim /etc/modules

    Add these two lines;

         i2c-dev
         i2c-bcm2708

    Now run this command(replace 1 with 0 for older model Pi)

         sudo i2cdetect -y 1

    If that doesnt work on your system you may alternatively use this:

         sudo i2cdetect -r 1

    you should now see the addresses of the i2c devices connected to your
    i2c bus

METHODS

 fileError

    returns IO::Handle->error() for the device handle since the last
    clearerr

 checkDevice

     $self->checkDevice($register_address)

    Check device

 selectDevice

     $self->selectDevice($register_address)

    Select device

 writeQuick

     $self->writeQuick($value)

    This sends a single bit to the device, at the place of the Rd/Wr bit.

 readByte

     $self->readByte()

    This reads a single byte from a device, without specifying a device
    register. Some devices are so simple that this interface is enough; for
    others, it is a shorthand if you want to read the same register as in
    the previous I2C command

 writeByte

     $self->writeByte()

    This operation is the reverse of readByte: it sends a single byte to a
    device.

 readByteData

     $self->readByteData($register_address)

    This reads a single byte from a device, from a designated register. The
    register is specified through the Comm byte.

 writeByteData

     $self->writeByteData($register_address,$value)

    This writes a single byte to a device, to a designated register. The
    register is specified through the Comm byte. This is the opposite of
    the Read Byte operation.

 readNBytes

     $self->readNBytes($lowest_byte_address, $number_of_bytes);

    Read together N bytes of Data in linear register order. i.e. to read
    from 0x28,0x29,0x2a

     $self->readNBytes(0x28,3);

 readWordData

     $self->readWordData($register_address)

    This operation is very like Read Byte; again, data is read from a
    device, from a designated register that is specified through the Comm
    byte. But this time, the data is a complete word (16 bits).

 writeWordData

     $self->writeWordData($register_address,$value)

    This is the opposite of the Read Word operation. 16 bits of data is
    written to a device, to the designated register that is specified
    through the Comm byte.

 processCall

     $self->processCall($register_address,$value)

    This command selects a device register (through the Comm byte), sends
    16 bits of data to it, and reads 16 bits of data in return.

 writeBlockData

     $self->writeBlockData($register_address, $values)

    Writes a maximum of 32 bytes in a single block to the i2c device. The
    supplied $values should be an array ref containing the bytes to be
    written.

    The register address should be one that is at the beginning of a
    contiguous block of registers of equal length to the array of values
    passed. Not adhering to this will almost certainly result in unexpected
    behaviour in the device.

 readBlockData

     $self->readBlockData($register_address, $numBytes)

    Read $numBytes form the given register address, data is returned as
    array

    The register address is often 0x00 or the value your device expects

    common usage with micro controllers that receive and send large amounts
    of data: they almost always needs a 'command' to be written to them
    then they send a response: e.g: 1) send 'command' with writeBlockData,
    or writeByteData, for example 'get last telegram' 2) read 'response'
    with readBlockData of size $numBytes, controller is sending the last
    telegram

 DEMOLISH

    Destructor

CONSTANTS

 I2C_SLAVE

 I2C_SLAVE_FORCE

CREATING YOUR OWN CHIPSET DRIVERS

    Writing your own chipset driver for your own i2c devices is quiet
    simple. You just need to know the i2c address of your device and the
    registers that you need to read or write. Example in the
    Device::I2C::ADV7611.

NOTES

    Based on the Device::SMBus without Moo. On my device Moo based script
    started 5 second.

    The SMBus was defined by Intel in 1995. It carries clock, data, and
    instructions and is based on Philips' I2C serial bus protocol. Its
    clock frequency range is 10 kHz to 100 kHz. (PMBus extends this to 400
    kHz.) Its voltage levels and timings are more strictly defined than
    those of I2C, but devices belonging to the two systems are often
    successfully mixed on the same bus. SMBus is used as an interconnect in
    several platform management standards including: ASF, DASH, IPMI.

USAGE

      * This module provides a simplified object oriented interface to the
      libi2c-dev library for accessing electronic peripherals connected on
      the I2C bus.

SEE ALSO

      * Device::SMBus

      * Device::I2C::ADV7611

      * IO::File

      * Fcntl

SUPPORT

 Bugs / Feature Requests

    Please report any bugs or feature requests through github at
    https://github.com/sv99/perl-device-i2c/issues. You will be notified
    automatically of any progress on your issue.

 Source Code

    This is open source software. The code repository is available for
    public review and contribution under the terms of the license.

    https://github.com/sv99/perl-device-i2c

      git clone git://github.com/sv99/perl-device-i2c.git

AUTHOR

    Slava Volkov <sv99@inbox.ru>

CONTRIBUTOR

    Slava Volkov <svolkov att cpan dott org>

COPYRIGHT AND LICENSE

    This software is copyright (c) 2016 by Slava Volkov.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.

