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 with a trailing call to ->get return Future instances.

read_register

   $value = $chip->read_register( $addr )->get

Reads a single byte register and returns its numerical value.

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

read_config

   $config = $chip->read_config->get

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   => "191.951.kHz",
   deviation         => "47.607kHz",

   data_rate         => "115.1kbps",

change_config

   $chip->change_config( %changes )->get

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
       MSG-500kb

read_marcstate

   $state = $chip->read_marcstate->get

Reads the MARCSTATE register and returns the state name.

read_chipstatus_rx

read_chipstatus_tx

   $status = $chip->read_chipstatus_rx->get

   $status = $chip->read_chipstatus_tx->get

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

   STATE                => string
   FIFO_BYTES_AVAILABLE => integer

read_pktstatus

   $status = $chip->read_pktstatus->get

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

   $chip->reset->get

Command the chip to perform a software reset.

flush_fifos

   $chip->flush_fifos->get

Command the chip to flush the RX and TX FIFOs.

start_rx

   $chip->start_rx->get

Command the chip to enter RX mode.

start_tx

   $chip->start_tx->get

Command the chip to enter TX mode.

idle

   $chip->idle->get

Command the chip to enter IDLE mode.

read_rxfifo

   $bytes = $chip->read_rxfifo( $len )->get

Reads the given number of bytes from the RX FIFO.

write_txfifo

   $chip->write_txfifo( $bytes )->get

Writes the given bytes into the TX FIFO.

receive

   $packet = $chip->receive->get

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

   $chip->transmit( $bytes )->get

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>