[WIP] Change gem structure

.travis.yml

@@ -1,4 +1,5 @@
 language: ruby
+cache: bundler
 rvm:
   - 1.9.3
   - 2.1.0

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

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

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

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

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