NAME

    Device::Chip::CC1101 - chip driver for a CC1101

DESCRIPTION

    This Device::Chip subclass provides specific communication to a Texas
    Instruments CC1101 radio transceiver chip attached to a computer via an
    SPI adapter.

    The reader is presumed to be familiar with the general operation of
    this chip; the documentation here will not attempt to explain or define
    chip-specific concepts or features, only the use of this module to
    access them.

CONSTRUCTOR

 new

       $chip = Device::Chip::CC1101->new( %ops )

    Constructs a new Device::Chip::CC1101 instance. Takes the following
    optional named arguments:

      * fosc

      Gives the XTAL oscillator frequency in Hz. This is used by the
      carrier_frequency to calculate the actual frequency from the chip
      config. A default of 26MHz applies if not supplied.

      * poll_interval

      Interval in seconds to poll the chip status after transmitting. A
      default of 20msec applies if not supplied.

METHODS

    The following methods documented in an await expression return Future
    instances.

 read_register

       $value = await $chip->read_register( $addr );

    Reads a single byte register and returns its numerical value.

    $addr should be between 0 and 0x3D, giving the register address.

 read_config

       $config = await $chip->read_config;

    Reads and returns the current chip configuration as a HASH reference.

    The returned hash will contain keys with capitalized names representing
    all of the config register fields in the datasheet, from registers
    IOCFG2 to RCCTRL0. Values are returned either as integers, or converted
    enumeration names. Where documented by the datasheet, the enumeration
    values are capitalised. Where invented by this module from the
    description they are given in lowercase.

    The value of PATABLE is also returned, rendered as a human-readable hex
    string in the form

       PATABLE => "01.23.45.67.89.AB.CD.EF",

    The following values are also returned, derived from the actual
    register values as a convenience.

       carrier_frequency => "800.000MHz",
       channel_spacing   => "191.951kHz",
       deviation         => "47.607kHz",
    
       data_rate         => "115.1kbps",

 change_config

       await $chip->change_config( %changes );

    Writes the configuration registers to apply the given changes. Any
    fields not specified will retain their current values. The value of
    PATABLE can also be set here. Values should be given using the same
    converted forms as the read_config returns.

    The following additional lowercase-named keys are also provided as
    shortcuts.

      * band => STRING

      A convenient shortcut to setting the FREQ and PATABLE configuration
      to one of the standard ISM bands. The names of these bands are

         433MHz
         868MHz

      * mode => STRING

      A convenient shortcut to setting the configuration state to one of
      the presets supplied with the module. The names of these presets are

         GFSK-1.2kb
         GFSK-38.4kb
         GFSK-100kb
         MSK-250kb
         MSK-500kb

 read_marcstate

       $state = await $chip->read_marcstate;

    Reads the MARCSTATE register and returns the state name.

 read_chipstatus_rx

 read_chipstatus_tx

       $status = await $chip->read_chipstatus_rx;
    
       $status = await $chip->read_chipstatus_tx;

    Reads the chip status word and returns a reference to a hash containing
    the following:

       STATE                => string
       FIFO_BYTES_AVAILABLE => integer

 read_pktstatus

       $status = await $chip->read_pktstatus;

    Reads the PKTSTATUS register and returns a reference to a hash
    containing boolean fields of the following names:

       CRC_OK CS PQT_REACHED CCA SFD GDO0 GDO2

 reset

       await $chip->reset;

    Command the chip to perform a software reset.

 flush_fifos

       await $chip->flush_fifos;

    Command the chip to flush the RX and TX FIFOs.

 start_rx

       await $chip->start_rx;

    Command the chip to enter RX mode.

 start_tx

       await $chip->start_tx;

    Command the chip to enter TX mode.

 idle

       await $chip->idle;

    Command the chip to enter IDLE mode.

 read_rxfifo

       $bytes = await $chip->read_rxfifo( $len );

    Reads the given number of bytes from the RX FIFO.

 write_txfifo

       await $chip->write_txfifo( $bytes );

    Writes the given bytes into the TX FIFO.

 receive

       $packet = await $chip->receive;

    Retrieves a packet from the RX FIFO, returning a HASH reference.

       data => STRING

    This method automatically strips the RSSI, LQI and CRC_OK fields from
    the data and adds them to the returned hash if the chip is configured
    with APPEND_STATUS.

       RSSI   => NUM (in units of dBm)
       LQI    => INT
       CRC_OK => BOOL

    This method automatically handles prepending the packet length if the
    chip is configured in variable-length packet mode.

    TODO: Note that, despite its name, this method does not currently wait
    for a packet to be available - the caller is responsible for calling
    "start_rx" and waiting for a packet to be received. This may be
    provided in a later version by polling chip status or using interrupts
    if Device::Chip makes them available.

 transmit

       await $chip->transmit( $bytes );

    Enters TX mode and sends a packet containing the given bytes.

    This method automatically handles prepending the packet length if the
    chip is configured in variable-length packet mode.

TODO

      * Polling/interrupts to wait for RX packet

      * Support addressing modes in "transmit" and "receive"

AUTHOR

    Paul Evans <leonerd@leonerd.org.uk>

