Update README, add schematics

Change-Id: Ide8e9ab8a40b2616d4ab20951631241599ec2c1a

Author: shawngit

README.md

@@ -1,27 +1,40 @@
 Android Things TensorFlow image classifier sample
 =====================================
 
-The Android Things TensorFlow image classifier sample demonstrates how to classify images.
-It uses camera to capture images and run TensorFlow inference on board to tell what kinds
-of dogs and cats in the images.  
+The Android Things TensorFlow image classifier sample app demonstrates how to capture an
+image by pushing a button, run TensorFlow on device to infer top three labels from the
+captured image, and then convert the result of labels into speech using text-to-speech.
 
-This project is based on the [TensorFlow Android Camera Demo](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/examples/android/),
-where the TensorFlow training was done using a type of convolutional neural network on ImageNet
-dataset codenamed Inception V3. The resulting data set is loaded into the sample app and
-it runs inference via TensorFlow Android Inference APIs. This simplified sample does not require
-native code and NDK and its only dependency on TensorFlow is a link to the TensorFlow Android
-Inference library in the form of an .aar file in build.gradle, which is provided and packaged
-into the project. 
+This project is based on the [TensorFlow Android Camera Demo TF_Classify app](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/examples/android/),
+where the TensorFlow training was done using Google inception model and the trained data set
+is used to run inference and generate classification labels via TensorFlow Android Inference
+APIs.
+
+This simplified sample app does not require native code or NDK and it links to TensorFlow
+via a gradle dependency on the TensorFlow Android Inference library in the form of
+an .aar library, which is included in the project here. 
 
 
 Pre-requisites
 --------------
 
-- Android Things compatible board
+- Android Things compatible board e.g. Raspberry Pi 3
 - Android Things compatible camera (for example, the Raspberry Pi 3 camera module)
 - Android Studio 2.2+
 - "Google Repository" from the Android SDK Manager
+- The following individual components:
+    - 1 push button
+    - 2 resistors
+    - 1 LED light
+    - 1 breadboard
+    - 1 speaker or earphone set
+    - jumper wires
+    - Optional: display e.g. TV
+
+Schematics
+----------
 
+![Schematics](rpi3_schematics_tf.png)
 
 Setup and Build
 ===============
@@ -32,6 +45,9 @@ To setup, follow these steps below.
 - Set up camera module
 - Set up the project in Android Studio
 - Inception model assets will be downloaded during build step
+- Connect push button to GPIO pin BCM21 (see schematics) 
+- Connect LED light to GPIO pin BCM6 (see schematics)
+- Connect speaker to audio jack (see schematics)
 
 
 Running
@@ -41,11 +57,12 @@ To run the `app` module on an Android Things board:
 
 1. Build the project within Android Studio and deploy to device via adb 
 2. Reboot the device to get all permissions granted; see [Known issues in release notes](https://developer.android.com/things/preview/releases.html#known_issues)
-3. Point camera to some images of dogs or cats
-4. See generated labels for your image in adb logcat e.g. Result: samoyed 
+3. Push the button when LED is ON to take a picture of e.g. dogs or cats
+4. Check result: LED light OFF during inference to prevent in a subsequent image advertently taken
+  - See generated labels for your image in adb logcat output e.g. Result: samoyed 
+  - If display is available e.g. via HDMI, see generated labels with respective confidence levels
+  - If speaker or earphones connected, listen to speech output of the generated labels
 
-If you have display like a TV, you will see images captured inside imageView with generated
-labels above inside a View.
 
 License
 -------