#Windows Remote Arduino

Windows Remote Arduino is an open-source Windows Runtime Component library which allows Makers to control an Arduino through a Bluetooth or USB connection! It is intended for Windows Runtime (WinRT) Developers who want to harness the power of Arduino hardware using the Windows Runtime Languages. Developers who include this component in their projects will automatically have access to its features in any of the WinRT languages (C++/CX, C# and JavaScript). The library is built on top of the Firmata protocol, which is implemented in a pre-packaged Firmata library included in the Arduino software obtained from http://arduino.cc.

View the open-source license.

##Overview Windows Remote Arduino bridges the gap between the software world and the physical world. By leveraging the power of Windows 10 we are able to expose new possibilities of Windows devices such as a Windows Phone, Surface Pro 3, Windows desktop, and even Raspberry Pi 2. Pair your device with an Arduino and gain access to a whole new set of realities with the world at your fingertips.

##Functionality Windows Remote Arduino enables the following functionality, right "out of the box".

1. GPIO – Analog and Digital I/O

• digitalWrite - Digital Write
• digitalRead - Digital Read
• analogWrite - Analog Write
• analogRead - Analog Read
• pinMode - Set the mode for any pins.
• Eventing - receive events when values change / are reported.

2. I2C/TwoWire

• Send/Receive data to devices over I2C.
• Subscribe to a device, repeated queries and automatic reporting.

3. Custom protocols via Firmata SysEx command

###The Microcontroller Arduinos are a series of open source microcontrollers built on an established platform. An individual Arduino device is a simple programmable device that is capable of tasks such as GPIO, but also more advanced communication protocols such as I2C. Makers have the ability of quickly hooking up sensors and other devices to an Arduino and using basic Arduino “sketches” to give instructions to the hardware.

However, devices like an Arduino are fundamentally limited by the single-threaded nature of a microcontroller. Remote Arduino brings together all of the physical control of an Arduino and the supercharged software abilities of Windows devices such as multi-threading, native file systems, simple internet access, and more.

###Windows 10 Windows 10 introduces the concept of a Universal Windows Platform (UWP). This means that developers can produce one solution that will work on any device running Windows 10, including Windows Phone 10 and Raspberry Pi 2. By including the Windows Remote Arduino library in your solution, you can turn any Windows device into a remote programming surface for your Arduino! Now it is possible to use the power of the Windows 10 operating system to open up a whole new set of advanced capabilities (and maker projects!) through the use of multi-threading, data storage, internet access, and natural user experiences.

#Structure The implementation is a three layer cake, where each layer provides an entry-point exposed as a Windows Runtime Component. A Maker can choose to use the topmost layer (RemoteWiring) which exposes an interface nearly identical to Arduino Wiring for all basic instructions like GPIO and communication to other devices through I2C. The vast majority of makers will likely never need more. However, a Maker can also choose to interface with the Firmata layer directly for creating advanced behaviors for all of those crazy creative ideas that you are bound to come up with.

##Layers There are three layers in the architecture of Windows Remote Arduino; they are interface, protocol, and transport. Each layer is a consumer of all layers below it, and therefore dependent on them. However, a layer is never dependent on anything above it. The layered construction allows individual layers to be swapped or utilized directly at any time, which provides the ability to supply alternate implementations at each layer. The layers, in their respective ordering, are given below.

• RemoteWiring (interface)
• Firmata (protocol)
• Serial (transport)

For example, the Firmata layer translates the requests of the RemoteWiring layer into the Firmata protocol and then passes them on to the Serial layer for transport to the Arduino (and vise-versa). The Firmata layer has no knowledge of what the Serial implementation looks like, or what method of transport is actually being used. However, the Firmata layer absolutely depends on this layer in order to work. In sharp contrast, the Firmata layer is not aware of the RemoteWiring layer's existence, and therefore could be interacted with directly.

###RemoteWiring The main interface class of the RemoteWiring layer is RemoteDevice, and it is the main API entry point that should be used in most cases. It offers an interface that is nearly identical to what you will find in the Arduino Wiring API, and should therefore be familiar if you have written Arduino sketches yourself. However, It is safe to say that all calls through this layer are directed to the Firmata layer below it, so it is only necessary to bypass or extend this layer when very advanced behaviors are desired for a project!

###Firmata The implementation of Firmata is taken directly from the Firmata repository, with absolute minimal changes (i.e. removing arduino/hardware dependencies), and is wrapped by a transparent Windows Runtime Component library class named UwpFirmata. The wrapper does not change or add functionality, it only provides parameter smoothing (i.e. char * -> String) and paradigm translation (i.e. callbacks -> events). This layer is completely independent from the RemoteWiring layer above it, so it can be used as a fully-functional Firmata implementation!

One advantage UwpFirmata provides through the Windows operating system is the ability to read inputs on a background thread, rather than being constricted to a single thread of execution. In most cases, this thread is created and managed completely by the library. However, if you choose to construct the Firmata layer (UwpFirmata object) yourself, you can choose to enable this feature or not. If your project does not require reading inputs from the Arduino (or if you want to handle them yourself), you may be interested in heading to the advanced usage section for more information!

###Serial Serial is the transport layer, which provides the physical communication between applications and the Arduino device. IStream is the interface which defines the requirements of a communication stream between the Arduino and the application itself. Currently, this is implemented in the default library with the BluetoothSerial class as well as USBSerial for wired connections on Windows 10. There are five functions which need to be implemented should you choose to extend the capabilities of the library with other communication methods. These functions MUST be guaranteed to be synchronous operations in order to be consumed by the Firmata layer.

• begin(int, SerialConfig) -> void -- initializes the stream, the SerialConfig is important when using USB. Default for Arduino is SERIAL_8N1
• end(void) -> void -- finalizes the stream
• available(void) -> int -- gets the number of bytes in the stream
• read(void) -> short -- reads a single character from the incoming stream
• write(char) -> void -- writes a single character to the outgoing stream

##RemoteDevice

A user-friendly wrapper for Firmata, providing an Arduino feel for GPIO and I2C. After adding this package to your solution either manually or through NuGet, you may construct a RemoteDevice object directly.

#Setup This section explains how to set up your Arduino and how to add the Windows Remote Arduino library to your Windows projects!

##Arduino Setup

Windows Remote Arduino uses the Firmata protocol, which has implementations in many languages including Arduino! The Arduino implementation is called StandardFirmata and comes pre-packaged with the Arduino software when you install it! Follow the steps below to upload the StandardFirmata sketch to your Arduino.

1. Download and install the Arduino software from http://arduino.cc.
2. Connect your Arduino device to the computer using USB.
3. Launch the Arduino application.
4. Verify that you have the correct Arduino board selected under Tools > Board
5. Verify that you have the correct COM Port selected under Tools > Port
6. In the Arduino IDE, navigate to File > Examples > Firmata > StandardFirmata
7. Press “Upload” to deploy the StandardFirmata sketch to the Arduino device.

That’s it! Your Arduino will now run the StandardFirmata sketch forever unless reprogrammed with a different sketch. You can now optionally disconnect your Arduino from the computer and power it in any way you choose. If you wish to use the recommended Bluetooth pairing between your devices, you will need to hook up a Bluetooth device to the Arduino. We recommend the SparkFun Bluetooth Mate Silver.

####Notes on Serial Commuinication

Some hardware setups may require additional considerations when it comes to setting up your Bluetooth device over the serial pins 0 and 1.

1. StandardFirmata uses the Serial lines to talk to a Bluetooth device or over USB. By default, it uses a baud rate of 57,600 bps. Depending on the configuration of your Bluetooth device, you may need to modify that rate. It can be found in the setup method and looks like this:

Firmata.begin(57600);

Simply change the begin parameter to match the configuration of your Bluetooth device. The most common configurations are 1152000, 57600, and 9600. The recommended SparkFun Bluetooth Mate devices use 115200 by default. If you are not sure of the default baud rate of your Bluetooth device, check the device documentation.

2. Many Arduino devices, such as the Leonardo and the Yun, use Serial1 (Rather than just Serial) for serial communications over pins 0 and 1. If you are using one of these devices, you will need to change the serial initialization procedure. You will want to remove the line Firmata.begin(57600); and replace it with the code below:

 Serial1.begin( 57600 );	//or your baud rate here, it will be 115200 if using the Bluetooth Mate Silver or Gold
 while( !Serial1 );
 Firmata.begin( Serial1 );

##Project Setup

Typically, you will want to add the Windows Remote Arduino library into your own Maker projects. The easiest way to do this is by installing the NuGet package into your projects. NuGet is a quick and easy way to automatically install the packages and setup dependencies. Unfortunately, we do not yet have support for NuGet in Windows 10.

For now, please refer to the manual installation instructions

#Usage This section explains the basic usage of Windows Remote Arduino. This is an excellent place to start if you are new to this library or Arduino Wiring itself. For advanced behaviors, see the advanced readme.

####C# Example:

        using namespace Microsoft.Maker.RemoteWiring;
        using namespace Microsoft.Maker.Serial;

		//create a bluetooth connection and pass it to the RemoteDevice
		IStream bt = new BluetoothSerial();
        RemoteDevice arduino = new RemoteDevice( bt );
		
		//always begin your IStream
		bt.begin( 115200, 0 );

        arduino.pinMode( 7, PinMode.OUTPUT );
        arduino.pinMode( 9, PinMode.INPUT );

        arduino.digitalWrite( 7, PinState.HIGH );
        UInt16 val = arduino.analogRead( 9 );

#####C++ Example:

        using namespace Microsoft::Maker::RemoteWiring;
        using namespace Microsoft::Maker::Serial;
		
		//create a bluetooth connection and pass it to the RemoteDevice
		IStream ^bt = ref new BluetoothSerial;
        RemoteDevice ^arduino = ref new RemoteDevice( bt );
		
		//always begin your IStream
		bt->begin( 115200, 0 );

        arduino->pinMode( 7, PinMode::OUTPUT );
        arduino->pinMode( 9, PinMode::INPUT );

        arduino->digitalWrite( 7, PinState::HIGH );
        uint16_t val = arduino->analogRead( 9 );

###Working with Analog

Analog input pins (A0, A1, A2, etc) have some unique properties which can cause some confusion working with them for the first time. This is mainly due to the contextualization the digital and analog pins when using Firmata. The Arduino IDE #defines special keywords for using these analog pins which basically tries to hide the issue from you, which can cause complications from another device when communicating with an Arduino over Firmata.

Let's consider the pinMode function for a moment...

An Arduino Uno has 14 digital pins numbered from 0 to 13. If you want to set the mode of pin 5 to INPUT, you would write pinMode( 5, INPUT ); in the Arduino IDE. If you wanted to do the same thing with analog pin 0, you would write pinMode( A0, ANALOG );. First, notice that we used ANALOG instead of INPUT. This is the first discrepancy of analog pins; Setting A0 to INPUT doesn't do what you think it would!

An Arduino only speaks binary. It understands numbers very well, but does not understand words like INPUT or ANALOG. INPUT, OUTPUT, HIGH, LOW, and many others are examples of macros defined by the Arduino IDE. These values are mapped to meaningful numbers without your knowledge or intervention. It is taken care of for you for simplicity and makes your code much more readable. However, the same is true for A0, therefore both arguments to the function call pinMode( A0, ANALOG ); are converted to numbers before the code is compiled to run on the Arduino. The value of ANALOG is always the same, but the value of A0 varies depending on the board you are using!

All pins are assigned a number. Analog pins are always numbered higher than the digital pins, so the pin number of A0 is actually different depending on how many digital pins your Arduino has. Since an Uno has 14 digital pins numbered from 0 to 13, pin A0 is actually pin 14, A1 is 15, A2 is 16, etc. A Mega has 54 digital pins, so A0 refers to pin 54.

Here is where this gets interesting: when using Remote Arduino, you need to be concious of the actual pin number when using generic functions like pinMode. Since we do not (currently) have any knowledge of what board is on the other end, we can't define A0 for you. Therefore, if you want to enable pin A0 for analogRead or analog events, you'll need to create your RemoteDevice object (called arduino here) and invoke the function like arduino.pinMode( 14, PinMode.ANALOG );

When reading the values, however, the context is clear. Since you cannot be referring to a digital pin when you invoke a function like analogRead, A0 is just 0, regardless of which type of board you are using. To be clear, this is not a design decision that this library has taken, this is how Firmata works. We are actively working to improve this in the future. For now, here is an example to help illustrate the issue:

	//We know that we have an Arduino Uno connected at the other end, which has 14 digital pins.
	//We want to read from a photocell connected to pin A4. Since A0 = 14, then A4 = 18
	
	byte NUM_DIGITAL_PINS = 14;
	byte photoPin = 4;
	
	arduino.pinMode( photoPin + NUM_DIGITAL_PINS, PinMode.ANALOG );	//sets the mode of A4 to ANALOG, 
	arduino.analogRead( photoPin );									//reads the value of A4

###Events

As previously mentioned, the RemoteWiring layer allows interactions with the RemoteDevice class to feel like interacting with the device directly through the Wiring API. However, Windows events give us the power to respond immediately to changes reported by the Arduino. Click here for more information about events.

For example, whenever you set an analog or digital pin to INPUT, the library will be notified whenever a pin value changes for digital pins, and every few milliseconds for analog pins. Windows Remote Arduino can pass these notifications on to you in the form of events. Simply subscribe to the event with a delegate function, and that function will automatically be called whenever it is appropriate!

####Note:

Events are often called on background threads. You may need to consider basic threading behaviors if you are storing data into an array or object created/used on your main thread, or if you are working with a user interface. When you use digital and analog read, the threading issues are taken care of by the library and are of no concern to you.

IStream bt;
RemoteDevice arduino;

public MyObject()
{
	bt = new Bluetooth Serial( "RNBT_BTLE" ); //Directly providing a device name to connect to
	arduino = new RemoteDevice( bt );

	//subscribe to the DigitalPinUpdateEvent with the name of the function to be called.
	arduino.DigitalPinUpdateEvent += MyDigitalPinUpdateCallback;
	
	//subscribe to the AnalogPinUpdateEvent with the name of the function to be called.
	arduino.AnalogPinUpdateEvent += MyAnalogPinUpdateCallback;

	//subscribe to the ConnectionEstablished event with the name of the function to be called.
	bt.ConnectionEstablished += MyConnectionEstablishedCallback;
	
	//always begin your IStream object
	bt.begin( 115200, 0 );
}

//this function will automatically be called when the bluetooth connection is established
public void MyConnectionEstablishedCallback()
{
	//set pin 7 to input mode to automatically receive callbacks when it changes
	arduino.pinMode( 7, PinMode.INPUT );
	
	arduino.pinMode( 8, OUTPUT );
	
	//you will also get a pin event when you change the value yourself.
	arduino.digitalWrite( 8, PinState.HIGH );
}

//this function will automatically be called whenever a digital pin value changes
public void MyDigitalPinUpdateCallback( byte pin, PinState state )
{
	Debug.WriteLine( "Pin D" + pin + " is now " + ( state == PinState.HIGH ? "HIGH" + "LOW" ) );
}

//this function will automatically be called whenever the analog values are reported. This is usually every few ms.
public void MyAnalogPinUpdateCallback( byte pin, UInt16 value )
{
	Debug.WriteLine( "Pin A" + pin + " is now " + value );
}

##Advanced Usage Please refer to the Advanced Usage documentation.

##Notes For more details, visit MSDN: How to specify device capabilities in a package manifest (Windows Runtime apps).