S15: Tree Node using Google Protocol Buffers

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• How well is Software & Hardware Design described?
• How well can this report be used to reproduce this project?
• Code Quality
• Overall Report Quality:
  • Software Block Diagrams
  • Hardware Block Diagrams

    Schematic Quality

  • Quality of technical challenges and solutions adopted.

Problem Statement

With the race to harness the value of big data in full swing, no one is happy about storing multiple versions of data. Its expensive, delays data availability, and just seems like a waste of time. Machines cannot afford to send and receive large chunk of data among each other. Sending large amount of data usually increases the transmission delays in the communication system and as a result the processing time of over all system increases. So, there is a burning need of faster, lighter and smarter way to process and transmit the data in the world of internet of things.

Basic Questions Asked:

1. What kind of protocol to use to transmit serial data ?
2. What is an efficient method for storing and exchanging the data?

Our Solution

Data Serialization

Historically, handling huge data has been a challenge for developers, mostly due to dependencies across multiple platforms and data access layers. Developers face situations where we want to deploy new code, but some other client relies on the old code. It can stop a deployment dead in its tracks. As models and needs mature more towards data as a service, developers expect that multiple clients would run different versions of a software platforms and even use different languages. In these cases, data serialization become quite important and serves as the best possible option.

So basically, serialization is used when large amounts of data have to be stored in flat files and retrieved at a later stage or to transport over the network. To achieve big data handling without serialization, it becomes too tedious, error-prone and complicated as the data structure is complex. So, we needed a serialization technique that is fast, compact format, easy to define, extensible and platform independent. That's where Google Protocol Buffers come into picture.

Google protocol buffers (GPB) is the best available way for data serialization between servers. By implementing lighter and micro controller compatible version of GPB - nanoPB - we created a faster and better machine to machine communication network. Google Protocol buffers provides neutral and efficient way of serializing structured data for the use in communication protocols.

Abstract

This project is to implement google protocol buffers for serialization of the data. In this main role of protocol buffers is to encode the data before sending it out via nordic wireless communication and decoding the received data on the receiver side.

• This project mainly focuses on Following topics:
  

  nanoPB
  • Studying different types of Protocol Buffers (GPB)

      Google Protocol Buffers
      Nano PB 
      Flat Buffers

• Implementing Nordic wireless communication between different boards by using these implemented google protocol buffers.

• Studying network architecture - Tree Achitecture

Objectives & Introduction

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Team Members & Responsibilities

• Aditya Bankar
  

• Aniruddha Kawade
  

• Shreeram Gopalakrishnan
  

• Vinod Pangul
  

Project Schedule

Following table gives the complete description of in-advance planning and deliverable for the project. This project schedule help us in scoping out the project and keep oneself in check with the progress.

Week No.	Start Date	Planned End Date	Task	Status	Actual End Date
1	03/31/2015	04/07/2015	* Decision on all required modules and placing the order online. * Research on Google Protocol Buffers	Done IOT Module , LCD module and Antennas for Nordic wireless, .	04/07/2015
2	04/06/2015	04/13/2015	* Environment setup of Google Protocol Buffer on windows and accomplish an example task such as hello world.	Done. GPB Environment setup with eclipse on windows have numerous issues,however we are able to compile the basic program successfully.(AI: to figure out run part of the compiled code). It works seamlessly on Linux but then we loose the advantage of having driver library provided by Preet.	04/29/2015
3	04/13/2015	04/20/2015	* Nordic Wireless: Ping Test between two SJOne boards.	Done	04/29/2015
4	04/20/2015	04/27/2015	* Nordic wireless all development and testing for 2-3 SJOne Boards. * Successful implementation of nanoPB ( GPB variant)	Done nanoPB encoder and decoder is successfully designed to have Nordic communication between two boards nanoPB encoder and decoder is successfully designed to have Nordic communication between two boards	04/30/2015
5	04/27/2015	05/04/2015	* Start code development for LCD module. * Testing Code via Google Protocol Buffers.	In Progress	--/--/----
6	05/04/2015	05/11/2015	* Integration of all modules with parallel testing.	Done	05/20/2015
7	05/11/2015	05/18/2015	* Integration of the code with Google Protocol Buffers.	Done	05/20/2015
8	05/18/2015	05/25/2015	* Final Testing and integration of additional features if time permits.	In progress	--/--/----
9	05/25/2015	05/25/2015	* Final Demo Day	Scheduled	--/--/----

Parts List & Cost

Following are the components and modules required for this project.

Parts List & Cost

Item#	Part Desciption	Vendor	Part Number	Qty	Cost
1	SJOne Board	SCU Room	Revision 2	3	$240
2	Antenna's	SCU room	CMPE 295	3	$12
3	LCD Module	New Haven	NHD-0216B3Z-FL-GBW-V3-ND	1	$27
4	Reserved for extra modules	NA	NA	NA	NA

Protocol Buffers

1. ===GOOGLE PROTOCOL BUFFERS===

Protocol Buffers was developed by Google for serializing data.

So, what is Serialization? According to Wikipedia, "serialization is the process of translating data structures or object state into a format that can be stored (for example, in a file or memory buffer, or transmitted across a network connection link) and reconstructed later in the same or another computer environment". Google Protocol Buffers is one of the methods used for serializing. The other famous method is XML. But, the main advantage of using Google Protocol Buffer over XML is that it is light weight, which makes it fast. It also has an easier implementation.

Currently, GPB has extended support for many programming languages, but C++, Java and Python are widely used.

Getting Started

The first step for us was to install the package available in https://github.com/google/protobuf/ and follow the instructions given in it. We first tried it in Windows Operating System. Because we were not able to successfully install in Windows, we moved to Linux.

Installation in Windows(Unix terminal)

The SJSU development package consists of a folder MSYS inside MINGW. The proto compiler is the most important thing and it was downloaded from https://developers.google.com/protocol-buffers/docs/downloads. It isused to compile .proto files which produces pb.h and pb.cc files. The protoc binary executable file was then placed inside the bin folder and its path defined in the environment variables. Msys is a unix like terminal used for configuring and building of applications which depend on Unix tools. The below steps for installing GPB were followed -

• Double click on ./autogen.sh. It will run in command prompt. This will generate a gtest folder. It consists of configure files, source code and libraries.
• Now in another window, open msys.bat file to start the unix like terminal.
• Navigate to the gtest folder and run ./configure
• This takes time and checks for gcc compatibility. Also, make sure that your antivirus is temporarily off. If not, the configure file may not be executed successfully and it will give errors like gcc configured
• Once configure runs successfully, type 'make' and execute it.
• After executing make, type 'make install' and execute it. Here is where, we faced issues.

The error screenshot is below -

Make install error

After posting on various google groups, we found out that, support has not yet been released for installing GPB with MinGW in Windows. Although, in Windows Visual Studio could have been used, we tried to use eclipse plugins to compile and run.

Installation in Windows(Eclipse) The plugin to download was available in https://code.google.com/p/protobuf-dt/wiki/Installing. The steps required to follow in eclipse are -

• Xtext and protobuf-dt is installed from http://download.eclipse.org/modeling/tmf/xtext/updates/composite/releases/. This is a descriptor i.e. highlights the keywords. To install the given link in Eclipse -
  • Inside the Eclipse CDT, click on 'Help' -> 'Install New Software'. A new dialog box opens where you will have to copy paste the link and click on 'Add'. The software finds the required plugins and you can complete the installation.
  • This can be similarly done for 'protobuf-dt' plugin.

Plugin update in eclipse

• After installing the plugin, we check if the option 'Protocol Buffers' is present in Windows -> Preferences. As seen in the below figure, we will use protoc in PATH variable and descriptor.proto location is given. Under the Options tab , Gen-C++ is checked so that after compiling, C++ src-gen (Source) is generated.

Protocol Buffer in eclipse Main tab

Protocol Buffer in eclipse Options tab

Installation in Linux Installing GPB in Linux is simple. Follow the methods similar to Windows Installation in Unix terminal and use it in Terminal in Linux. The installation will be successful because all make files are supported for linux.

Nordic Wireless

For the wireless communication between two or more SJone controllers, we have used the Nordic wireless communication. SJone board itself have onboard Nordic wireless chip nrf24L01 configured with Serial Peripheral Interface(SPI) which also features Enhanced ShockBurst™. This helps in automatic packet handling and timing. During transmit, ShockBurst™ assembles the packet and clocks the bits in the data packet for transmission. During receive, ShockBurst™ constantly searches for a valid address in the demodulated signal.
The nrf24L01 + Full three level FIFO for both TX and RX direction helps in achieving maximum 0-10Mbps with 4 wire SPI interface. The following Diagram shows internal working of nordic wireless.

Hardware Design

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Project's Functional Diagram

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Design & Implementation

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My Issue #1

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Project Source Code

• Sourceforge Source Code Link

References

Acknowledgement

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References Used

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• Google's Nanopb web: http://koti.kapsi.fi/jpa/nanopb/docs/concepts.html
• Nanopb API references: http://koti.kapsi.fi/jpa/nanopb/docs/reference.html

Appendix

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