#YCommunicator

Version 1.1

A protocol and implementation of "device to device" serial communication, originally planned for connecting Arduino and other devices via serial communication.

Goal

• Setup simple communication between Arduino and other devices
• 2 way communication, both parties are equal: both can initialize a command to the other party, both can respond to commands sent from the other party.
• Simple API: allow developers to define commands and register functions on those commands.
• Availability: support multiple devices by having creating libraries for all major OSs and languages.

Implementations:

• Arduino package including examples: https://github.com/oyagev/YCommunicator-Arduino
• Android application and source code: https://github.com/oyagev/YCommunicator-Android
• C++ implementation: https://github.com/oyagev/YCommunicator-CPP
• Java implementation: https://github.com/oyagev/YCommunicator-Java

##Protocol Definitions

The protocol defines "Packets" and "Instructions". Packets are transmitted serially with a fixed "delimiter byte" and an "escape byte".

• Delimiter: 0x7c
• Escape: 0x00

###Packet: A packet is the minimum transmitable unit. It wraps the payload - a byte array of unspecified data.

#####Structure:

1. unsigned char[] payload - actual instructions

• unsigned short int checksum

#####Notes:

• Packet size is at least payload size + 2

###Instruction: An Instruction is the most basic operational syntax that can be exchanged between the devices.

#####Structure:

1. unsigned char type - types are COMMAND | RETURN

• unsigned char command - predefined instruction to be preformed
• unsigned char[] data - additional values

#####Notes:

• data length is always payload_len - 2

##Functional (API) Prototype

#####YCommunicator

• +void write(byte) - write incoming bytes into the communicator
• +byte read() - read outgoing bytes from the communicator
• +int available() - Get number of bytes available for output
• +dispatch(byte type, byte command, byte[] data, byte data_langth) - Dispatch an instruction
• +registerDefaultCallback(callback_function(byte type, byte command, byte[] data, byte data_langth)) - Defualt function to trigger when an instruction arrives. Only triggered if callback function was not defined for the instruction's command
• +registerCallback(byte command, callback_function(byte type, byte command, byte[] data, byte data_langth)) - Trigger this function when an instruction arrives with a specific command value.

Help is needed!

For this project to be attractive, we need an implementation of the above API on several devices and languages: Arduino (daa...), Android, iOS, Python, Java, etc. Also, I suggest to create an application for out-of-the-box integration:

1. Arduino example sketch.

• Mobile App that supports adding/defining controls and sensors (see below)
• PC application with graphic UI that supports adding/defining controls.