WIP I2C read - #10

lib/pi_piper/bcm2835.rb

@@ -59,6 +59,7 @@ def self.pin_read(pin)
     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,
@@ -84,5 +85,12 @@ def self.i2c_transfer_bytes(data)
       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

lib/pi_piper/i2c.rb

@@ -43,6 +43,10 @@ def write(params)
       Platform.driver.i2c_transfer_bytes data
     end
 
+    def read(bytes)
+      Platform.driver.i2c_read_bytes(bytes)
+    end
+
   end
 
 end