Class: Crubyflie::RadioDriver

Inherits:
Object
  • Object
show all
Defined in:
lib/crubyflie/driver/radio_driver.rb

Overview

This layer takes care of connecting to the crazyradio and managing the incoming and outgoing queues. This is done by spawing a thread. It also provides the interface to scan for available crazyflies to which connect

Constant Summary collapse

CALLBACKS =

Currently used callbacks that can be passed to connect()

[:link_quality_cb,
:link_error_cb]
OUT_QUEUE_MAX_SIZE =

Default size for the outgoing queue

50
RETRIES_BEFORE_DISCONNECT =

Default number of retries before disconnecting

20

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initializeRadioDriver

Initialize the driver. Creates new empty queues.


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# File 'lib/crubyflie/driver/radio_driver.rb', line 76

def initialize()
    @uri = nil
    @in_queue = Queue.new()
    @out_queue = Queue.new()
    Thread.abort_on_exception = true
    @radio_thread = nil
    @callbacks = {}
    @crazyradio = nil
    @out_queue_max_size = nil
    @retries_before_disconnect = nil
    @shutdown_thread = false
end

Instance Attribute Details

#out_queue_max_sizeObject (readonly)

Returns the value of attribute out_queue_max_size


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# File 'lib/crubyflie/driver/radio_driver.rb', line 73

def out_queue_max_size
  @out_queue_max_size
end

#retries_before_disconnectObject (readonly)

Returns the value of attribute retries_before_disconnect


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# File 'lib/crubyflie/driver/radio_driver.rb', line 73

def retries_before_disconnect
  @retries_before_disconnect
end

#uriObject (readonly)

Returns the value of attribute uri


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# File 'lib/crubyflie/driver/radio_driver.rb', line 72

def uri
  @uri
end

Instance Method Details

#connect(uri_s, callbacks = {}, opts = {}) ⇒ Object

Connect to a Crazyflie in the specified URI

Parameters:

  • uri_s (String)

    a radio uri like radio://<dongle>/<ch>/<rate>

  • callbacks (Hash) (defaults to: {})

    blocks to call (see CALLBACKS contant values)

  • opts (Hash) (defaults to: {})

    options. Currently supported :retries_before_disconnect (defaults to 20) and :out_queue_max_size (defaults to 50)

Raises:


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# File 'lib/crubyflie/driver/radio_driver.rb', line 99

def connect(uri_s, callbacks={}, opts={})
    # Check if apparently there is an open link

    if @crazyradio
        m = "Active link to #{@uri.to_s}. Disconnect first"
        raise OpenLink.new(m)
    end

    # Parse URI to initialize Crazyradio
    # @todo: better control input. It defaults to 0
    @uri = CrubyflieURI.new(uri_s)
    dongle_number = @uri.dongle.to_i
    channel = @uri.channel.to_i
    rate = @uri.rate

    # @todo this should be taken care of in crazyradio
    case rate
    when "250K"
        rate = CrazyradioConstants::DR_250KPS
    when "1M"
        rate = CrazyradioConstants::DR_1MPS
    when "2M"
        rate = CrazyradioConstants::DR_2MPS
    else
        raise InvalidURIException.new("Bad radio rate")
    end

    # Fill in the callbacks Hash
    CALLBACKS.each do |cb|
        if passed_cb = callbacks[cb]
            @callbacks[cb] = passed_cb
        else
            raise CallbackMissing.new("Callback #{cb} mandatory")
        end
    end

    @retries_before_disconnect = opts[:retries_before_disconnect] ||
        RETRIES_BEFORE_DISCONNECT
    @out_queue_max_size = opts[:out_queue_max_size] ||
        OUT_QUEUE_MAX_SIZE

    # Initialize Crazyradio and run thread
    cradio_opts = {
        :channel => channel,
        :data_rate => rate
    }
    @crazyradio = Crazyradio.factory(cradio_opts)
    start_radio_thread()

end

#disconnect(force = nil) ⇒ Object

Disconnects from the crazyradio

Parameters:

  • force (TrueClass, FalseClass) (defaults to: nil)

    . Kill the thread right away, or wait for out_queue to empty


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# File 'lib/crubyflie/driver/radio_driver.rb', line 153

def disconnect(force=nil)
    kill_radio_thread(force)
    @in_queue.clear()
    @out_queue.clear()

    return if !@crazyradio
    @crazyradio.close()
    @crazyradio = nil
end

#get_statusObject

Get status from the crazyradio. @see Crazyradio#status


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# File 'lib/crubyflie/driver/radio_driver.rb', line 241

def get_status
    return Crazyradio.status()
end

#receive_packet(non_block = true) ⇒ CRTPPacket?

Fetch a packet from the incoming queue

Returns:

  • (CRTPPacket, nil)

    a packet from the queue, or nil when there is none


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# File 'lib/crubyflie/driver/radio_driver.rb', line 180

def receive_packet(non_block=true)
    begin
        return @in_queue.pop(non_block)
    rescue ThreadError
        return nil
    end
end

#scan_interfaceArray

List available Crazyflies

Returns:

  • (Array)

    List of radio URIs where a crazyflie was found

Raises:

  • (OpenLink)

    if the Crazyradio is connected already


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# File 'lib/crubyflie/driver/radio_driver.rb', line 200

def scan_interface
    raise OpenLink.new("Cannot scan when link is open") if @crazyradio
    begin
        @crazyradio = Crazyradio.factory()
        results = {}
        @crazyradio[:arc] = 1
        @crazyradio[:data_rate] = Crazyradio::DR_250KPS
        results["250K"] = scan_radio_channels()
        @crazyradio[:data_rate] = Crazyradio::DR_1MPS
        results["1M"]   = scan_radio_channels()
        @crazyradio[:data_rate] = Crazyradio::DR_2MPS
        results["2M"]   = scan_radio_channels()

        uris = []
        results.each do |rate, channels|
            channels.each do |ch|
                uris << "radio://0/#{ch}/#{rate}"
            end
        end
        return uris
    rescue USBDongleException
        raise
    rescue Exception
        retries ||= 0
        logger.error("Unknown error scanning interface: #{$!}")
        @crazyradio.reopen()
        retries += 1
        if retries < 2
            logger.error("Retrying")
            sleep 0.5
            retry
        end
        return []
    ensure
        @crazyradio.close() if @crazyradio
        @crazyradio = nil
    end
end

#send_packet(packet) ⇒ Object

Place a packet in the outgoing queue When not connected it will do nothing

Parameters:


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# File 'lib/crubyflie/driver/radio_driver.rb', line 166

def send_packet(packet)
    return if !@crazyradio
    if (s = @out_queue.size) >= @out_queue_max_size
        m = "Reached #{s} elements in outgoing queue"
        @callbacks[:link_error_cb].call(m)
        disconnect()
    end

    @out_queue << packet if !@shutdown_thread
end