Class: LittleWire::SPI

Inherits:
Object
  • Object
show all
Defined in:
lib/littlewire/spi.rb

Instance Method Summary collapse

Constructor Details

#initialize(wire) ⇒ SPI

Returns a new instance of SPI.



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# File 'lib/littlewire/spi.rb', line 2

def initialize wire
  @wire = wire
  @wire.control_transfer(function: :setup_spi)
  raise "SPI requires LittleWire firmware 1.1. Yours = #{@wire.version}" unless @wire.version_hex >= 0.11
end

Instance Method Details

#debug ⇒ Object

get debug status



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# File 'lib/littlewire/spi.rb', line 26

def debug
  @wire.control_transfer(function: :debug_spi, dataIn: 8)
  @wire.control_transfer(function: :read_buffer, dataIn: 8).unpack('c').first
end

#delay=(number) ⇒ Object

change spi delay setting



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# File 'lib/littlewire/spi.rb', line 21

def delay= number
  @wire.control_transfer(function: :spi_update_delay, wValue: number)
end

#send(send, auto_chipselect = false) ⇒ Object

send and receive a message of up to four bytes



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# File 'lib/littlewire/spi.rb', line 9

def send send, auto_chipselect = false
  mode = auto_chipselect ? 1 : 0
  bytes = send.bytes.to_a
  @wire.control_transfer(
    bRequest: 0xF0 + send.length + (mode << 3),
    wValue: bytes[1].to_i << 8 | bytes[0].to_i,
    wIndex: bytes[3].to_i << 8 | bytes[2].to_i,
    dataIn: bytes.length
  )
end