Navigation using Audio Jack

Author: Jayanta Kumar Ghoshal

Date: 2015-11-27

Table of Contents

Abstract

Introduction

Navigation Using Audio Jack

Using the Audio Jack as Data Interface

Transmitting Data

Receiving Data

Block Diagram

Conclusion

References

AbstractA major problem that most of the Car infotainment face is absence or extra expense on navigation

system. This document serves as a solution for the navigation system for the car infotainment with

absolutely no extra hardware cost.

In the era of smart devices, we can expect 90 percent of customer is using smart phones like

Android, IOS, Windows etc. This smart devices are already embedded with lots of sensors and at

the same time capable of computing in gigabytes.

Using smart devices, Navigation can be achieved in any car infotainment system via audio jack as

a data interface.

Fig:

• Keywords: Navigation, Audio jack as a data interface.

Introduction• Car Navigation system allows an automobile driver to see where he or she is

on map at a given time. GPS(Global Positioning system) based navigation uses special satellite to

calculate the location.

• Navigation System is one of the very important component of car

infotainment system. Though many of the car infotainment doesn’t support.

• Navigation system is already available in the existing smart phones. A car infotainment can use the

in-built navigation system using a simple 3.5mm audio jack. An audio jack is still the most future-

proof phone to car connection method.

• Regarding the connection method, 3.5mm audio cable is the most user friendly with plug and play

feature, least power consumption and widely available.

• The basic idea behind this is to use Smartphone’s existing navigation system to get current

location, and routing detail from the phone and transfer it to the car infotainment system via audio

jack.

Navigation using Audio Jack

Navigation could be achieved in car infotainment system by fetching the following:

All the required location and

Turn by turn routing detail from a Smartphone via audio jack.

At present Audio jack in car infotainment system is only used to stream audio and video.

There are many commercial products where audio jack has been used to transfer data.

For example:

• Square : Process credit card.

• iHealth Lab’s Glucometer : measure glucose level.

• The Irdroid : provides infrared remote functions to control TVs, set-top boxes, and audio

components

• Flojack : NFC reader, and writer, for Apple mobile

devices.

• 2nd Gen. iPod Shuffle

• Audio jack can also be used as a data interface, which is the key point of this navigation

solution.

• By continuous updating of location and routing detail a user can experience a full fledge

navigation in its infotainment system without spending any extra expense for Navigation.

Audio jack are meant to transfer analog signal(sound/audio), and the data needed to transfer for

navigation is digital(0 and 1).

These digital data can be transferred by combining audio and data

using FSK(Frequency-Shift Keying) Modulation.

Using Audio jack as a data interface

FSK is a frequency modulation scheme in which digital

information is transmitted through discrete frequency changes

of a carrier wave.

Smartphone can get an audio signal from the built in

microphone and digital data can be encoded in that.

Once encoded, play the audio signal.

On the other end this audio signal could be recorded and

decoded the required data from it.

Transmitting data

When we send 0X00FF data value, the first step is to

convert the digital value to the analog signal. We need to

modulate the data value. Normally we use sine wave

carrier for the analog signal.

The second step is to play the analog signal.

Receiving data

As a receiver we need to translate the analog signal to a

data value. Demodulate the signal to remove the carrier

signal, and decode the data by transmitting protocol

FSK Modulation

Digital Data

Analog/Audio Signal

Modulated Signal

FSK Demodulation

Received Signal

Analog/Audio Signal

Digital Data

Audio

Jack

Sender

Receiver

Fig: Block Diagram

Conclusion

Using audio jack is a very easy and simple way to drive navigation in infotainment system.

Whereas no setup and plug and play feature makes it more user friendly and efficient.

Advantages of using audio jack for navigation is as below:

• Zero power transmission

• Less battery consumption, when compared to Bluetooth and Wi-Fi.

• Wide availability of audio jack in Smartphone.

• Easy to connect.

Limitation of using audio jack:

• Audio jack provide data transfer rate of about 1Kbps, using short length cable and good quality

of conductor can improve it by up to 5-6Kbps.

• Need to care of noise at receiver side by setting offset.

References

Sl. No. Title & Author Source Publication Details

1

Using the Audio Jack as

Data Interface on Android*

Systems

https://software.intel.com/en-

us/android/articles/using-the-

audio-jack-as-data-interface-on-

android-systems

Date: 2015-01-09

Li Liang

2

Transferring data using

audio signal in androidhttp://www.slideshare.net/Sudar/tr

ansfering-data-using-audio-signal-

in-android

Date: 2012-04-07

Sudar Muthu

3Phone connector

https://en.wikipedia.org/wiki/Phon

e_connector_(audio)

Date: 2015-10-24

Wikipedia

Questions ?

Please comment!!!

Thank You!