diff --git a/java/libraries/io/examples/I2CScreen/I2CScreen.pde b/java/libraries/io/examples/I2CScreen/I2CScreen.pde
index 71a761598..e16e6542a 100644
--- a/java/libraries/io/examples/I2CScreen/I2CScreen.pde
+++ b/java/libraries/io/examples/I2CScreen/I2CScreen.pde
@@ -8,11 +8,15 @@ void setup() {
 
   // the display can be set to one of these two addresses: 0x3c (default) or 0x3d
   // (they might be listed as 0x7a and 0x7b on the circuit board)
-  oled = new SSD1306(I2C.list()[0], 0x3c);
+
+  // you might need to use a different interface on other SBCs
+  oled = new SSD1306("i2c-1", 0x3c);
 }
 
 void draw() {
-	line(0, 0, 127, 63);
-	line(0, 63, 127, 0);
-	oled.sendImage(get());
+  background(0);
+  stroke(255);
+  line(0, 0, 127, 63);
+  line(0, 63, 127, 0);
+  oled.sendImage(get());
 }
diff --git a/java/libraries/io/examples/I2CScreen/SSD1306.pde b/java/libraries/io/examples/I2CScreen/SSD1306.pde
index 6c9f343aa..dee79a027 100644
--- a/java/libraries/io/examples/I2CScreen/SSD1306.pde
+++ b/java/libraries/io/examples/I2CScreen/SSD1306.pde
@@ -61,7 +61,7 @@ class SSD1306 extends I2C {
     img.loadPixels();
     for (int y=startY; y < height && y-startY < 64; y++) {
       for (int x=startX; x < width && x-startX < 128; x++) {
-        if (brightness(img.pixels[y*img.width+x]) < 128) {
+        if (128 <= brightness(img.pixels[y*img.width+x])) {
           // this isn't the normal (scanline) mapping, but 8 pixels below each other at a time
           // white pixels have their bit turned on
           frame[x + (y/8)*128] |= (1 << (y % 8));
diff --git a/java/libraries/io/examples/SPIAnalogDigitalOOP/MCP3001.pde b/java/libraries/io/examples/SPIAnalogDigitalOOP/MCP3001.pde
index e25869633..944e097e5 100644
--- a/java/libraries/io/examples/SPIAnalogDigitalOOP/MCP3001.pde
+++ b/java/libraries/io/examples/SPIAnalogDigitalOOP/MCP3001.pde
@@ -7,13 +7,13 @@ class MCP3001 extends SPI {
 
   MCP3001(String dev) {
     super(dev);
-    super.settings(500000, SPI.MSBFIRST, SPI.MODE0);
+    settings(500000, SPI.MSBFIRST, SPI.MODE0);
   }
 
   float getAnalog() {
     // dummy write, actual values don't matter
     byte[] out = { 0, 0 };
-    byte[] in = super.transfer(out);
+    byte[] in = transfer(out);
     // some input bit shifting according to the datasheet p. 16
     int val = ((in[0] & 0x1f) << 5) | ((in[1] & 0xf8) >> 3);
     // val is between 0 and 1023
diff --git a/java/libraries/io/examples/SPIAnalogDigitalOOP8/MCP3008.pde b/java/libraries/io/examples/SPIAnalogDigitalOOP8/MCP3008.pde
index 5ae8d9ef0..ee3affd0f 100644
--- a/java/libraries/io/examples/SPIAnalogDigitalOOP8/MCP3008.pde
+++ b/java/libraries/io/examples/SPIAnalogDigitalOOP8/MCP3008.pde
@@ -8,7 +8,7 @@ class MCP3008 extends SPI {
 
   MCP3008(String dev) {
     super(dev);
-    super.settings(500000, SPI.MSBFIRST, SPI.MODE0);
+    settings(500000, SPI.MSBFIRST, SPI.MODE0);
   }
 
   float getAnalog(int channel) {
@@ -19,7 +19,7 @@ class MCP3008 extends SPI {
     byte[] out = { 0, 0, 0 };
     // encode the channel number in the first byte
     out[0] = (byte)(0x18 | channel);
-    byte[] in = super.transfer(out);
+    byte[] in = transfer(out);
     int val = ((in[1] & 0x03) << 8) | (in[2] & 0xff);
     // val is between 0 and 1023
     return val/1023.0;
diff --git a/java/libraries/io/src/native/Makefile b/java/libraries/io/src/native/Makefile
index c35acf87e..6a2c00373 100644
--- a/java/libraries/io/src/native/Makefile
+++ b/java/libraries/io/src/native/Makefile
@@ -3,7 +3,7 @@ OBJS := impl.o
 CC := gcc
 
 # prefix with -m32 to compile for linux32
-CFLAGS := -std=gnu99 -fPIC -g
+CFLAGS := -std=gnu99 -fPIC -g -ffast-math
 CFLAGS += -I$(shell dirname $(shell realpath $(shell which javac)))/../include
 CFLAGS += -I$(shell dirname $(shell realpath $(shell which javac)))/../include/linux
 LDFLAGS := -shared
diff --git a/java/libraries/io/src/processing/io/GPIO.java b/java/libraries/io/src/processing/io/GPIO.java
index a0b970955..a4042122d 100644
--- a/java/libraries/io/src/processing/io/GPIO.java
+++ b/java/libraries/io/src/processing/io/GPIO.java
@@ -447,13 +447,32 @@ public class GPIO {
    *  Waits for the value of an input pin to change
    *  @param pin GPIO pin
    *  @param mode what to wait for: GPIO.CHANGE, GPIO.FALLING or GPIO.RISING
-   *  @param timeout don't wait more than timeout milliseconds (-1 waits indefinitely)
-   *  @return true if the interrupt occured, false if the timeout occured
    *  @webref
    */
-  public static boolean waitForInterrupt(int pin, int mode, int timeout) {
+  public static void waitFor(int pin, int mode) {
+    waitForInterrupt(pin, mode, -1);
+  }
+
+
+  /**
+   *  Waits for the value of an input pin to change
+   *
+   *  This function will throw a RuntimeException in case of a timeout.
+   *  @param pin GPIO pin
+   *  @param mode what to wait for: GPIO.CHANGE, GPIO.FALLING or GPIO.RISING
+   *  @param timeout don't wait more than timeout milliseconds
+   *  @webref
+   */
+  public static void waitFor(int pin, int mode, int timeout) {
     enableInterrupt(pin, mode);
-    return waitForInterrupt(pin, timeout);
+    if (waitForInterrupt(pin, timeout) == false) {
+      throw new RuntimeException("Timeout occurred");
+    }
+  }
+
+
+  public static boolean waitForInterrupt(int pin, int mode, int timeout) {
+    throw new RuntimeException("The waitForInterrupt function has been renamed to waitFor. Please update your sketch accordingly.");
   }
 
 
diff --git a/java/libraries/io/src/processing/io/PWM.java b/java/libraries/io/src/processing/io/PWM.java
index 455a659e4..2a8fe19f2 100644
--- a/java/libraries/io/src/processing/io/PWM.java
+++ b/java/libraries/io/src/processing/io/PWM.java
@@ -117,7 +117,7 @@ public class PWM {
     // XXX: implicit clear()?
     // XXX: also check GPIO
 
-    String fn = "/sys/class/pwm/" + chip + "/export";
+    String fn = "/sys/class/pwm/" + chip + "/unexport";
     int ret = NativeInterface.writeFile(fn, Integer.toString(channel));
     if (ret < 0) {
       if (ret == -2) {    // ENOENT
diff --git a/java/libraries/io/src/processing/io/RPI.java b/java/libraries/io/src/processing/io/RPI.java
deleted file mode 100644
index 523ffeb12..000000000
--- a/java/libraries/io/src/processing/io/RPI.java
+++ /dev/null
@@ -1,88 +0,0 @@
-/* -*- mode: java; c-basic-offset: 2; indent-tabs-mode: nil -*- */
-
-/*
-  Copyright (c) The Processing Foundation 2015
-  Hardware I/O library developed by Gottfried Haider as part of GSoC 2015
-
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public
-  License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
-
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General
-  Public License along with this library; if not, write to the
-  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
-  Boston, MA  02111-1307  USA
-*/
-
-package processing.io;
-
-
-/**
- *  @webref
- */
-public class RPI {
-
-  /*
-   * The Raspberry Pi has a 2x20 pin header for connecting various peripherals.
-   * The following constants describe how the pins of this header correspond
-   * to the pin numbering used by the CPU and by software ("GPIO pin number").
-   *
-   * You can use this class to refer to a pin by its location on the header:
-   * e.g. GPIO.digitalWrite(RPI.PIN7, GPIO.HIGH)
-   *
-   * Alternatively, if you know a pins "true" pin number (GPIO number), you
-   * can use it directly. The following is equivalent to the example above:
-   * GPIO.digitalWrite(4, GPIO.HIGH)
-   *
-   * PIN1 is located on the "top left" of the column of pins, close to the two
-   * LEDs. PIN2 is next to it. PIN3 is below PIN1, and it goes on like this.
-   * See also: http://pi.gadgetoid.com/pinout
-   */
-
-  public static final int PIN1 = -1;    /* 3v3 Power, can source up to 50 mA */
-  public static final int PIN2 = -1;    /* 5v Power, connected to input power */
-  public static final int PIN3 = 2;     /* GPIO 2, also: I2C data */
-  public static final int PIN4 = -1;    /* 5v Power, connected to input power */
-  public static final int PIN5 = 3;     /* GPIO 3, also: I2C clock */
-  public static final int PIN6 = -1;    /* Ground */
-  public static final int PIN7 = 4;     /* GPIO 4 */
-  public static final int PIN8 = 14;    /* GPIO 14, also: Serial TX */
-  public static final int PIN9 = -1;    /* Ground */
-  public static final int PIN10 = 15;   /* GPIO 15, also: Serial RX */
-  public static final int PIN11 = 17;   /* GPIO 17 */
-  public static final int PIN12 = 18;   /* GPIO 18 */
-  public static final int PIN13 = 27;   /* GPIO 27 */
-  public static final int PIN14 = -1;   /* Ground */
-  public static final int PIN15 = 22;   /* GPIO 22 */
-  public static final int PIN16 = 23;   /* GPIO 23 */
-  public static final int PIN17 = -1;   /* 3v3 Power, can source up to 50 mA */
-  public static final int PIN18 = 24;   /* GPIO 24 */
-  public static final int PIN19 = 10;   /* GPIO 10, also: SPI MOSI */
-  public static final int PIN20 = -1;   /* Ground */
-  public static final int PIN21 = 9;    /* GPIO 9, also: SPI MISO */
-  public static final int PIN22 = 25;   /* GPIO 25 */
-  public static final int PIN23 = 11;   /* GPIO 11, also: SPI SCLK */
-  public static final int PIN24 = 8;    /* GPIO 8, also: SPI Chip Select 0 */
-  public static final int PIN25 = -1;   /* Ground */
-  public static final int PIN26 = 7;    /* GPIO 7, also: SPI Chip Select 1 */
-  public static final int PIN27 = 0;    /* GPIO 0, also: HAT I2C data, reserved [currenly not accessible] */
-  public static final int PIN28 = 1;    /* GPIO 1, also HAT I2C data, reserved [currenly not accessible] */
-  public static final int PIN29 = 5;    /* GPIO 5 */
-  public static final int PIN30 = -1;   /* Ground */
-  public static final int PIN31 = 6;    /* GPIO 6 */
-  public static final int PIN32 = 12;   /* GPIO 12 */
-  public static final int PIN33 = 13;   /* GPIO 13 */
-  public static final int PIN34 = -1;   /* Ground */
-  public static final int PIN35 = 19;   /* GPIO 19, also: SPI MISO [currenly not accessible] */
-  public static final int PIN36 = 16;   /* GPIO 16 */
-  public static final int PIN37 = 26;   /* GPIO 26 */
-  public static final int PIN38 = 20;   /* GPIO 20, also: SPI MISO [currenly not accessible] */
-  public static final int PIN39 = -1;   /* Ground */
-  public static final int PIN40 = 21;   /* GPIO 21, also: SPI CLK [currenly not accessible] */
-}