diff --git a/.travis.yml b/.travis.yml
index 3dfc619..e968680 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,5 @@
 language: ruby
+cache: bundler
 rvm:
   - 1.9.3
   - 2.1.0
diff --git a/Gemfile.lock b/Gemfile.lock
index 17aaa59..9fcf70e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,19 +1,21 @@
 PATH
   remote: .
   specs:
-    bcm2835 (0.1.0)
+    pi_piper-bcm2835 (0.1.0)
       ffi
-      pi_piper
+      pi_piper (>= 2.0.0)
 
 GEM
   remote: https://rubygems.org/
   specs:
     coderay (1.1.0)
     diff-lcs (1.2.5)
+    docile (1.1.5)
     eventmachine (1.0.9)
     ffi (1.9.10)
+    json (1.8.3)
     method_source (0.8.2)
-    pi_piper (1.9.9)
+    pi_piper (2.0.0)
       eventmachine (= 1.0.9)
       ffi
     pry (0.10.3)
@@ -34,17 +36,23 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.4.0)
     rspec-support (3.4.1)
+    simplecov (0.11.2)
+      docile (~> 1.1.0)
+      json (~> 1.8)
+      simplecov-html (~> 0.10.0)
+    simplecov-html (0.10.0)
     slop (3.6.0)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  bcm2835!
   bundler (~> 1.11)
+  pi_piper-bcm2835!
   pry
   rake (~> 10.0)
   rspec (~> 3.0)
+  simplecov
 
 BUNDLED WITH
    1.11.2
diff --git a/lib/bcm2835/driver.rb b/lib/bcm2835/driver.rb
deleted file mode 100644
index 2208f07..0000000
--- a/lib/bcm2835/driver.rb
+++ /dev/null
@@ -1,135 +0,0 @@
-require 'ffi'
-require 'pi_piper/frequency'
-
-module Bcm2835
-  # The Bcm2835 module is not intended to be directly called.
-  # It serves as an FFI library for PiPiper::SPI and PiPiper::I2C
-  class Driver
-    extend FFI::Library
-
-    ffi_lib File.dirname(__FILE__) + '/../../bin/libbcm2835.so'
-    @pins = []
-
-    SPI_MODE0 = 0
-    SPI_MODE1 = 1
-    SPI_MODE2 = 2
-    SPI_MODE3 = 3
-
-    I2C_REASON_OK         = 0  # Success
-    I2C_REASON_ERROR_NACK = 1  # Received a NACK
-    I2C_REASON_ERROR_CLKT = 2  # Received Clock Stretch Timeout
-    I2C_REASON_ERROR_DATA = 3  # Not all data is sent / received
-
-    attach_function :init, :bcm2835_init, [], :uint8
-    attach_function :close, :bcm2835_close, [], :uint8
-    
-    # Sets the Function Select register for the given pin, which configures the
-    # pin as Input, Output or one of the 6 alternate functions.
-    attach_function :gpio_select_function, :bcm2835_gpio_fsel,    [:uint8, :uint8], :void
-    # attach_function :gpio_set,             :bcm2835_gpio_set,     [:uint8], :void
-    # attach_function :gpio_clear,           :bcm2835_gpio_clr,     [:uint8], :void
-    # attach_function :gpio_level,           :bcm2835_gpio_lev,     [:uint8], :uint8
-
-    # pin support...
-    attach_function :pin_set_pud, :bcm2835_gpio_set_pud, [:uint8, :uint8], :void
-    
-    def self.pin_input(pin)
-      export(pin)
-      pin_direction(pin, 'in')
-    end
-
-    def self.pin_set(pin, value)
-      File.write("/sys/class/gpio/gpio#{pin}/value", value)
-    end
-
-    def self.pin_output(pin)
-      export(pin)
-      pin_direction(pin, 'out')
-    end
-
-    def self.pin_read(pin)
-      File.read("/sys/class/gpio/gpio#{pin}/value").to_i
-    end
-
-    # PWM support...
-    attach_function :pwm_clock,     :bcm2835_pwm_set_clock,  [:uint32], :void
-    attach_function :pwm_mode,      :bcm2835_pwm_set_mode,   [:uint8, :uint8, :uint8], :void
-    attach_function :pwm_range,     :bcm2835_pwm_set_range,  [:uint8, :uint32], :void
-    attach_function :pwm_data,      :bcm2835_pwm_set_data,   [:uint8, :uint32], :void
-
-    def self.pin_direction(pin, direction)
-      File.write("/sys/class/gpio/gpio#{pin}/direction", direction)
-    end
-
-    # Exports pin and subsequently locks it from outside access
-    def self.export(pin)
-      File.write('/sys/class/gpio/export', pin)
-      @pins << pin unless @pins.include?(pin)
-    end
-
-    def self.release_pin(pin)
-      File.write('/sys/class/gpio/unexport', pin)
-      @pins.delete(pin)
-    end
-
-    def self.release_pins
-      @pins.dup.each { |pin| release_pin(pin) }
-    end
-
-    # NOTE to use: chmod 666 /dev/spidev0.0
-    def self.spidev_out(array)
-      File.open('/dev/spidev0.0', 'wb') { |f| f.write(array.pack('C*')) }
-    end
-
-    # SPI support...
-    attach_function :spi_begin,       :bcm2835_spi_begin,            [], :uint8
-    attach_function :spi_end,         :bcm2835_spi_end,              [], :uint8
-    attach_function :spi_transfer,    :bcm2835_spi_transfer,         [:uint8], :uint8
-    attach_function :spi_transfernb,  :bcm2835_spi_transfernb,       [:pointer, :pointer, :uint], :void
-    attach_function :spi_clock,       :bcm2835_spi_setClockDivider,  [:uint8], :void
-    attach_function :spi_bit_order,   :bcm2835_spi_setBitOrder,      [:uint8], :void
-    attach_function :spi_chip_select, :bcm2835_spi_chipSelect,       [:uint8], :void
-    attach_function :spi_set_data_mode, :bcm2835_spi_setDataMode,    [:uint8], :void
-    attach_function :spi_chip_select_polarity, 
-                    :bcm2835_spi_setChipSelectPolarity,              [:uint8, :uint8], :void
-
-    #I2C support...
-    attach_function :i2c_begin,      :bcm2835_i2c_begin,             [], :void
-    attach_function :i2c_end,        :bcm2835_i2c_end,               [], :void
-    attach_function :i2c_write,      :bcm2835_i2c_write,             [:pointer, :uint], :uint8
-    attach_function :i2c_set_address,:bcm2835_i2c_setSlaveAddress,   [:uint8], :void
-    attach_function :i2c_set_clock_divider, :bcm2835_i2c_setClockDivider,     [:uint16], :void
-    attach_function :i2c_read,       :bcm2835_i2c_read,              [:pointer, :uint], :uint8
-
-    def self.i2c_allowed_clocks
-      [100.kilohertz,
-       399.3610.kilohertz,
-       1.666.megahertz,
-       1.689.megahertz]
-    end
-
-    def self.spi_transfer_bytes(data)
-      data_out = FFI::MemoryPointer.new(data.count)
-      data_in = FFI::MemoryPointer.new(data.count)
-      (0..data.count - 1).each { |i| data_out.put_uint8(i, data[i]) }
-
-      spi_transfernb(data_out, data_in, data.count)
-
-      (0..data.count - 1).map { |i| data_in.get_uint8(i) }
-    end
-
-    def self.i2c_transfer_bytes(data)
-      data_out = FFI::MemoryPointer.new(data.count)
-      (0..data.count - 1).each{ |i| data_out.put_uint8(i, data[i]) }
-
-      i2c_write data_out, data.count
-    end
-
-    def self.i2c_read_bytes(bytes)
-      data_in = FFI::MemoryPointer.new(bytes)
-      i2c_read(data_in, bytes) #TODO reason codes 
-
-      (0..bytes - 1).map { |i| data_in.get_uint8(i) }
-    end
-  end
-end
diff --git a/lib/pi_piper/bcm2835.rb b/lib/pi_piper/bcm2835.rb
index a3a1637..c033238 100644
--- a/lib/pi_piper/bcm2835.rb
+++ b/lib/pi_piper/bcm2835.rb
@@ -1,5 +1,15 @@
-require "pi_piper/bcm2835/version"
+require 'pi_piper/bcm2835/version'
+require 'pi_piper/bcm2835/pin'
+require 'pi_piper/bcm2835/spi'
+require 'pi_piper/bcm2835/i2c'
+require 'pi_piper/bcm2835/driver'
 
 module PiPiper
-  autoload PiPiper::Bcm2835, "pi_piper/bcm2835/bcm2835"
+  module Bcm2835
+    class << self
+      def driver
+        @driver ||= PiPiper::Bcm2835::Driver.new
+      end
+    end
+  end
 end
diff --git a/lib/pi_piper/bcm2835/bcm2835.rb b/lib/pi_piper/bcm2835/bcm2835.rb
deleted file mode 100644
index 37127f0..0000000
--- a/lib/pi_piper/bcm2835/bcm2835.rb
+++ /dev/null
@@ -1,4 +0,0 @@
-module PiPiper
-  class Bcm2835 < Driver
-  end
-end
diff --git a/lib/pi_piper/bcm2835/driver.rb b/lib/pi_piper/bcm2835/driver.rb
new file mode 100644
index 0000000..9a708ec
--- /dev/null
+++ b/lib/pi_piper/bcm2835/driver.rb
@@ -0,0 +1,48 @@
+require 'ffi'
+require 'pry'
+
+module PiPiper
+  module Bcm2835
+    # The Bcm2835 module is not intended to be directly called.
+    # It serves as an FFI library for PiPiper::SPI and PiPiper::I2C
+    class Driver
+      include PiPiper::Bcm2835::Pin
+      include PiPiper::Bcm2835::SPI
+      include PiPiper::Bcm2835::I2C
+      include FFI::Library
+
+      def initialize
+        ffi_lib File.expand_path('../../../../bin/libbcm2835.so', __FILE__)
+        setup_gpio
+        setup_pwm
+        setup_spi
+        setup_i2c
+      end
+
+      def setup_gpio
+        attach_function :init, :bcm2835_init, [], :uint8
+        attach_function :close, :bcm2835_close, [], :uint8
+        
+        # Sets the Function Select register for the given pin, which configures the
+        # pin as Input, Output or one of the 6 alternate functions.
+        attach_function :gpio_select_function, :bcm2835_gpio_fsel,    [:uint8, :uint8], :void
+        # attach_function :gpio_set,             :bcm2835_gpio_set,     [:uint8], :void
+        # attach_function :gpio_clear,           :bcm2835_gpio_clr,     [:uint8], :void
+        # attach_function :gpio_level,           :bcm2835_gpio_lev,     [:uint8], :uint8
+
+        # pin support...
+        attach_function :pin_set_pud, :bcm2835_gpio_set_pud, [:uint8, :uint8], :void
+      end
+
+      def setup_pwm
+        # PWM support...
+        attach_function :pwm_clock,     :bcm2835_pwm_set_clock,  [:uint32], :void
+        attach_function :pwm_mode,      :bcm2835_pwm_set_mode,   [:uint8, :uint8, :uint8], :void
+        attach_function :pwm_range,     :bcm2835_pwm_set_range,  [:uint8, :uint32], :void
+        attach_function :pwm_data,      :bcm2835_pwm_set_data,   [:uint8, :uint32], :void
+      end
+
+
+    end
+  end
+end
diff --git a/lib/pi_piper/bcm2835/i2c.rb b/lib/pi_piper/bcm2835/i2c.rb
new file mode 100644
index 0000000..b388dd1
--- /dev/null
+++ b/lib/pi_piper/bcm2835/i2c.rb
@@ -0,0 +1,42 @@
+require 'ffi'
+require 'pi_piper/frequency'
+
+module PiPiper
+  module Bcm2835
+    module I2C
+      I2C_REASON_OK         = 0  # Success
+      I2C_REASON_ERROR_NACK = 1  # Received a NACK
+      I2C_REASON_ERROR_CLKT = 2  # Received Clock Stretch Timeout
+      I2C_REASON_ERROR_DATA = 3  # Not all data is sent / received
+
+      def setup_i2c
+        attach_function :i2c_begin,      :bcm2835_i2c_begin,             [], :void
+        attach_function :i2c_end,        :bcm2835_i2c_end,               [], :void
+        attach_function :i2c_write,      :bcm2835_i2c_write,             [:pointer, :uint], :uint8
+        attach_function :i2c_set_address,:bcm2835_i2c_setSlaveAddress,   [:uint8], :void
+        attach_function :i2c_set_clock_divider, :bcm2835_i2c_setClockDivider,     [:uint16], :void
+        attach_function :i2c_read,       :bcm2835_i2c_read,              [:pointer, :uint], :uint8
+      end
+
+      def i2c_allowed_clocks
+        [100.kilohertz,
+         399.3610.kilohertz,
+         1.666.megahertz,
+         1.689.megahertz]
+      end
+
+      def i2c_transfer_bytes(data)
+        data_out = FFI::MemoryPointer.new(data.count)
+        (0..data.count - 1).each{ |i| data_out.put_uint8(i, data[i]) }
+        i2c_write(data_out, data.count)
+      end
+
+      def i2c_read_bytes(bytes)
+        data_in = FFI::MemoryPointer.new(bytes)
+        i2c_read(data_in, bytes) #TODO reason codes 
+
+        (0..bytes - 1).map { |i| data_in.get_uint8(i) }
+      end
+    end
+  end
+end
diff --git a/lib/pi_piper/bcm2835/pin.rb b/lib/pi_piper/bcm2835/pin.rb
new file mode 100644
index 0000000..3fc7157
--- /dev/null
+++ b/lib/pi_piper/bcm2835/pin.rb
@@ -0,0 +1,61 @@
+require 'set'
+
+module PiPiper
+  module Bcm2835
+    module Pin
+      def pins
+        @pins ||= Set.new
+      end
+
+      def pin_input(pin)
+        export(pin)
+        pin_direction(pin, 'in')
+      end
+
+      def pin_set(pin, value)
+        File.write("/sys/class/gpio/gpio#{pin}/value", value)
+      end
+
+      def pin_output(pin)
+        export(pin)
+        pin_direction(pin, 'out')
+      end
+
+      def pin_read(pin)
+        raise ArgumentError, "Pin #{pin} is not exported" if unexported?(pin)
+        File.read("/sys/class/gpio/gpio#{pin}/value").to_i
+      end
+
+      def unexport(pin)
+        raise ArgumentError, "Pin #{pin} not exported" if unexported?(pin)
+        File.write('/sys/class/gpio/unexport', pin)
+        pins.delete(pin)
+      end
+
+      def unexport_all
+        pins.dup.each { |pin| unexport(pin) }
+      end
+
+      def exported?(pin)
+        pins.include?(pin)
+      end
+
+      def unexported?(pin)
+        !exported?(pin)
+      end
+
+      private
+      
+      def export(pin)
+        raise ArgumentError, "Pin #{pin} already exported" if exported?(pin)
+        File.write('/sys/class/gpio/export', pin)
+        pins << pin
+      end
+
+      def pin_direction(pin, direction)      
+        File.write("/sys/class/gpio/gpio#{pin}/direction", direction)
+      end
+
+    end
+  end
+end
diff --git a/lib/pi_piper/bcm2835/spi.rb b/lib/pi_piper/bcm2835/spi.rb
new file mode 100644
index 0000000..05851db
--- /dev/null
+++ b/lib/pi_piper/bcm2835/spi.rb
@@ -0,0 +1,40 @@
+require 'ffi'
+
+module PiPiper
+  module Bcm2835
+    module SPI
+      SPI_MODE0 = 0
+      SPI_MODE1 = 1
+      SPI_MODE2 = 2
+      SPI_MODE3 = 3
+
+      def setup_spi
+        attach_function :spi_begin,       :bcm2835_spi_begin,            [], :uint8
+        attach_function :spi_end,         :bcm2835_spi_end,              [], :uint8
+        attach_function :spi_transfer,    :bcm2835_spi_transfer,         [:uint8], :uint8
+        attach_function :spi_transfernb,  :bcm2835_spi_transfernb,       [:pointer, :pointer, :uint], :void
+        attach_function :spi_clock,       :bcm2835_spi_setClockDivider,  [:uint8], :void
+        attach_function :spi_bit_order,   :bcm2835_spi_setBitOrder,      [:uint8], :void
+        attach_function :spi_chip_select, :bcm2835_spi_chipSelect,       [:uint8], :void
+        attach_function :spi_set_data_mode, :bcm2835_spi_setDataMode,    [:uint8], :void
+        attach_function :spi_chip_select_polarity, 
+                        :bcm2835_spi_setChipSelectPolarity,              [:uint8, :uint8], :void
+      end
+
+      # NOTE to use: chmod 666 /dev/spidev0.0
+      def spidev_out(array)
+        File.open('/dev/spidev0.0', 'wb') { |f| f.write(array.pack('C*')) }
+      end
+
+      def spi_transfer_bytes(data)
+        data_out = FFI::MemoryPointer.new(data.count)
+        data_in = FFI::MemoryPointer.new(data.count)
+        (0..data.count - 1).each { |i| data_out.put_uint8(i, data[i]) }
+
+        spi_transfernb(data_out, data_in, data.count)
+
+        (0..data.count - 1).map { |i| data_in.get_uint8(i) }
+      end
+    end
+  end
+end
diff --git a/lib/pi_piper/bcm2835/version.rb b/lib/pi_piper/bcm2835/version.rb
index bcc346f..afddd14 100644
--- a/lib/pi_piper/bcm2835/version.rb
+++ b/lib/pi_piper/bcm2835/version.rb
@@ -1,5 +1,5 @@
 module PiPiper
-  class Bcm2835
-    VERSION = "0.1.0"
+  module Bcm2835
+    VERSION = '0.1.0'
   end
 end
diff --git a/spec/pi_piper/bcm2835/bcm2835_spec.rb b/spec/pi_piper/bcm2835/bcm2835_spec.rb
new file mode 100644
index 0000000..a50c56c
--- /dev/null
+++ b/spec/pi_piper/bcm2835/bcm2835_spec.rb
@@ -0,0 +1,17 @@
+require 'spec_helper'
+
+describe PiPiper::Bcm2835 do
+  it 'has a version number' do
+    expect(PiPiper::Bcm2835::VERSION).not_to be nil
+  end
+
+  describe '#driver' do
+    let(:driver) { PiPiper::Bcm2835::Driver }
+    it 'should return the Bcm2835 driver' do
+      allow_any_instance_of(driver).to receive(:ffi_lib)
+      allow_any_instance_of(driver).to receive(:attach_function)
+
+      expect(PiPiper::Bcm2835.driver).to be_a(PiPiper::Bcm2835::Driver)
+    end
+  end
+end
diff --git a/spec/pi_piper/bcm2835/driver_spec.rb b/spec/pi_piper/bcm2835/driver_spec.rb
new file mode 100644
index 0000000..86d4925
--- /dev/null
+++ b/spec/pi_piper/bcm2835/driver_spec.rb
@@ -0,0 +1,14 @@
+require 'spec_helper'
+
+describe PiPiper::Bcm2835::Driver do
+  let(:driver) { PiPiper::Bcm2835::Driver }
+  describe '#initialize' do
+    it 'should run the setup attach_functions' do
+      allow_any_instance_of(driver).to receive(:ffi_lib)
+      allow_any_instance_of(driver).to receive(:attach_function)
+      expect_any_instance_of(driver).to receive(:attach_function)
+
+      driver.new
+    end
+  end
+end
diff --git a/spec/pi_piper/bcm2835/i2c_spec.rb b/spec/pi_piper/bcm2835/i2c_spec.rb
new file mode 100644
index 0000000..d69188b
--- /dev/null
+++ b/spec/pi_piper/bcm2835/i2c_spec.rb
@@ -0,0 +1,33 @@
+require 'spec_helper'
+
+describe PiPiper::Bcm2835::I2C do
+  let(:i2c) { Class.new { extend PiPiper::Bcm2835::I2C } }
+
+  describe '.setup_i2c' do
+    it 'should run the :attach_function through ffi' do
+      expect(i2c).to receive(:attach_function).exactly(6).times
+      i2c.setup_i2c
+    end
+  end
+
+  describe '.i2c_allowed_clocks' do
+    it 'should return the allowed clock rates' do
+      expect(i2c.i2c_allowed_clocks).to be_a(Array)
+    end
+  end
+
+  describe '.i2c_transfer_bytes' do
+    it 'should write bytes via i2c' do
+      allow(i2c).to receive(:i2c_write)
+      i2c.i2c_transfer_bytes([1, 2, 3, 4])
+    end
+  end
+
+  describe '.i2c_read_bytes' do
+    it 'should read the bytes through i2c' do
+      allow(i2c).to receive(:i2c_read)
+      # read 4 bytes
+      expect(i2c.i2c_read_bytes(0x4)).to eq([0, 0, 0, 0])
+    end
+  end
+end
diff --git a/spec/pi_piper/bcm2835/pin_spec.rb b/spec/pi_piper/bcm2835/pin_spec.rb
new file mode 100644
index 0000000..e745c97
--- /dev/null
+++ b/spec/pi_piper/bcm2835/pin_spec.rb
@@ -0,0 +1,133 @@
+require 'spec_helper'
+
+describe PiPiper::Bcm2835::Pin do
+  let(:pin) { Class.new { extend PiPiper::Bcm2835::Pin } }
+
+  before(:each) do
+    allow(File).to receive(:write).with('/sys/class/gpio/export', 4)
+    allow(File).to receive(:write).with('/sys/class/gpio/gpio4/direction', 'in')
+  end
+
+  describe '.pins' do
+    it 'should instantiate an empty set' do
+      expect(pin.pins).to be_a(Set)
+      expect(pin.pins).to be_empty
+    end
+
+    it 'should return the exported pins' do
+      pin.pin_input(4)
+      expect(pin.pins).to contain_exactly(4)
+    end
+  end
+
+  describe '.pin_input' do    
+    it 'should export the pin in the `in` direction' do
+      expect(pin).to receive(:export).with(4)      
+      pin.pin_input(4)
+    end
+
+    it 'should keep state of exported pins' do
+      pin.pin_input(4)
+      expect(pin.pins).to contain_exactly(4)
+    end
+
+    it 'should raise an error if pin is exported already' do
+      pin.pin_input(4)
+      expect { pin.pin_input(4) }.to raise_error(ArgumentError)
+    end
+  end
+
+  describe '.pin_set' do
+    it 'should set the value of the pin' do
+      expect(File).to receive(:write).with('/sys/class/gpio/gpio4/value', '1')
+      pin.pin_set(4, '1')
+    end
+  end
+
+  describe '.pin_output' do
+    before(:each) do
+      allow(File).to(
+        receive(:write).with('/sys/class/gpio/gpio4/direction', 'out'))
+    end
+    
+    it 'should export the pin in the `in` direction' do
+      expect(pin).to receive(:export).with(4)      
+      pin.pin_output(4)
+    end
+
+    it 'should keep state of exported pins' do
+      pin.pin_output(4)
+      expect(pin.pins).to contain_exactly(4)
+    end
+
+    it 'should raise an error if pin is exported already' do
+      pin.pin_output(4)
+      expect { pin.pin_output(4) }.to raise_error(ArgumentError)
+    end
+  end
+
+  describe '.pin_read' do
+    it 'should return the value of the pin read' do
+      pin.pin_input(4)
+      expect(File).to(
+        receive(:read).with('/sys/class/gpio/gpio4/value').and_return(1))
+      expect(pin.pin_read(4)).to eq(1)
+    end
+
+    it 'should raise an error if pin is not exported' do
+      expect { pin.pin_read(4) }.to raise_error(ArgumentError)
+    end
+  end
+
+  describe '.unexport' do
+    it 'should unexport the pin' do
+      expect(File).to receive(:write).with('/sys/class/gpio/unexport', 4)
+      pin.pin_input(4)
+      pin.unexport(4)
+    end
+
+    it 'should raise an error if pin is not exported' do
+      expect { pin.unexport(4) }.to raise_error(ArgumentError)
+    end
+  end
+
+  describe '.unexport_all' do
+    it 'should unexport all the export pins' do
+      allow(File).to receive(:write).with('/sys/class/gpio/export', 4)
+      allow(File).to receive(:write).with('/sys/class/gpio/gpio4/direction', 'in')
+      allow(File).to receive(:write).with('/sys/class/gpio/export', 5)
+      allow(File).to receive(:write).with('/sys/class/gpio/gpio5/direction', 'in')
+      
+      expect(File).to receive(:write).with('/sys/class/gpio/unexport', 4)
+      expect(File).to receive(:write).with('/sys/class/gpio/unexport', 5)
+
+      pin.pin_input(4)
+      pin.pin_input(5)
+
+      pin.unexport_all
+      expect(pin.pins).to be_empty
+    end
+  end
+
+  describe '.exported?' do
+    it 'should return true if the pin is exported' do
+      pin.pin_input(4)
+      expect(pin.exported?(4)).to be(true)
+    end
+
+    it 'should return false if the pin is not exported' do
+      expect(pin.exported?(4)).to be(false)
+    end
+  end
+
+  describe '.unexported?' do
+    it 'should return true if the pin is not exported' do
+      expect(pin.unexported?(4)).to be(true)
+    end
+
+    it 'should return false if the pin is exported' do
+      pin.pin_input(4)
+      expect(pin.unexported?(4)).to be(false)
+    end
+  end
+end
diff --git a/spec/pi_piper/bcm2835/spi_spec.rb b/spec/pi_piper/bcm2835/spi_spec.rb
new file mode 100644
index 0000000..91840d4
--- /dev/null
+++ b/spec/pi_piper/bcm2835/spi_spec.rb
@@ -0,0 +1,30 @@
+require 'spec_helper'
+
+describe PiPiper::Bcm2835::SPI do
+  let(:spi) { Class.new { extend PiPiper::Bcm2835::SPI } }
+
+  describe '.setup_spi' do
+    it 'should run the :attach_function through ffi' do
+      expect(spi).to receive(:attach_function).exactly(9).times
+      spi.setup_spi
+    end
+  end
+
+  describe '.spidev_out' do
+    it 'should write to spidev' do
+      expect(File).to receive(:open).with('/dev/spidev0.0', 'wb')
+      spi.spidev_out([1, 2, 3])
+    end
+  end
+
+  describe '.spi_transfer_bytes' do
+    it 'should transfer bytes through spi interface' do
+      expect(spi).to(
+        receive(:spi_transfernb).with(instance_of(FFI::MemoryPointer),
+                                      instance_of(FFI::MemoryPointer),
+                                      instance_of(Fixnum)))
+      spi.spi_transfer_bytes([0x0, 0x1, 0x2])
+    end
+  end
+
+end
diff --git a/spec/pi_piper/bcm2835_spec.rb b/spec/pi_piper/bcm2835_spec.rb
deleted file mode 100644
index ad68f86..0000000
--- a/spec/pi_piper/bcm2835_spec.rb
+++ /dev/null
@@ -1,7 +0,0 @@
-require 'spec_helper'
-
-describe PiPiper::Bcm2835 do
-  it 'has a version number' do
-    expect(PiPiper::Bcm2835::VERSION).not_to be nil
-  end
-end