Using an Android Smartphone as a Head-Unit

datvichrox2 · 19th February 2016, 12:03

This was going to be a proof of concept of an idea that has been gnawing at me for a while. Its a hobby project that I did on my 2004 Palio 1.2 and I am happy with the way it has turned out.

Using an Android Smartphone as a Head-Unit-project-intro.jpg

What I have in my car currently, this came with the car when I bought it used in 2008:

Blaupunkt LongBeach c31 - cassette player , with aux input at the rear
Blaupunkt 542 speakers (4)

What I will have after this mod:
Android Phone which serves as audio head unit and navigator
(The Blaupunkt components will remain as it is)

If this works, it will make my 10 year old car-cassette player useful in 2016 as well.

Android phones can pretty much provide all the major functionality that is needed in a car - Audio Playback and Navigation. Even a cheap Android phone can replace a car head unit. It can also be made to respond to voice commands.

Installing a phone/tablet in a car has been done before - lookup Android Nexus7 in-car installations and many examples on t-bhp itself.

How this project differs is in the way inputs are handled. I hate interacting with touch screens in car entertainment systems - it takes a while to get things done because of the small buttons and menus and this can be distracting during driving.

The major features should be easily accessed and controlled with as few interactions as possible and with dedicated hardware controls.

This is where the Arduino Uno comes in. I will be adding hardware buttons, rotary encoders and program the Arduino Uno to respond to them. The Arduino Uno will communicate with the Android phone using bluetooth. The Arduino Uno tells the phone which button was pressed or which knob was turned and in which direction. The Phone can respond accordingly - this requires some custom programming to listen to specific commands over bluetooth, mentioned below.

A custom Android service in the phone will be listening solely to the Arduino Uno via bluetooth and based on the code that the Arduino sends, will perform actions on the Android phone.

Some of the actions that the custom Android app will trigger are as follows:

Launch Maps
Launch Music Player
Reduce / Increase Volume (this will be sent to the head unit)
Play Next Song
Play Prev Song
Pause/Play

The car cassette player which is currently installed will be put into AUX mode permanently and will take its audio input from the Android phone. It will continue to provide amplification and controlling of the car speakers. That will be its sole purpose.

Advantages of this system:

Can be updated easily by using custom apps on the Android and custom code on the Arduino.
Any car headunit can be used as long as it has AUX-input.
The car's ECU system can be read and displayed on the Android phone. If there's a problem with the car, you would know immediately.
Access to google maps and apps.
It can have its own sim card and data connection. I could send a remote message to the car and it could be programmed to respond with its current location.
Can be extended to support steering wheel controls as well.
Disadvantages of this system:

It is a complete D-I-Y (do-it-yourself) project and will take a long time to complete. I started this around 6 months ago and spend whatever time I get in the weekends.
It needs hardware customization as well, if you want it to be a plush-fit. This is needed to make it look professional.
Need to learn Android programming
Need to learn Arduino programming
Need to acquire Soldering skills and basic electronics design
The reason I chose a phone over a tablet, is because of the space available in the car. It is a single DIN space and I cannot put in a tablet as that would require a double DIN space.

Here is a picture depicting the components involved and how the communication happens between the devices:

Using an Android Smartphone as a Head-Unit-arduino-project.jpg

datvichrox2 · 19th February 2016, 12:32

Some pictures of the install:

Using an Android Smartphone as a Head-Unit-side-shot-compressed.jpg

Using an Android Smartphone as a Head-Unit-screenoff.jpg

With the screen off. Tasker turns off the screen 7 secs after the phone loses power. An app called DeepSleep Battery saver makes sure I don't loose too much battery when I don't use the car. So far I have seen that the battery drops at-most 1% when left overnight.

Using an Android Smartphone as a Head-Unit-homescreen.jpg

The Home screen. This is actually a really large custom Widget made using UCCW (available on google play).

Music - opens poweramp
Maps - opens gmaps
CarMode - still not functional, I am writing a custom app to talk to the Palio ECU and display some geeky stuff (since torque wont work

)

Using an Android Smartphone as a Head-Unit-musicplayer.jpg

PowerAmp music player.

Using an Android Smartphone as a Head-Unit-audiocontrols.jpg

PowerAmp has good equalizer controls and my current cheap speakers never sounded better. Yet to find a good skin for landscape mode.

Using an Android Smartphone as a Head-Unit-googlemaps.jpg

What I like most about having an android phone in the car - Google Maps.

Using an Android Smartphone as a Head-Unit-behind-panel-compressed.jpg

Behind the acrylic panel - Arduino Uno fitted into the Palio clock slot, with all with wiring going through it, including aux, usb power and wiring for the knobs (rotary encoders).

The black acrylic panel is held to the AC panel using 3 door magnets. Driven more than 600 kms with this at highway speeds. No issues.

The phone is a Xiaomi Redmi 1s, running Mokee Custom Rom Lollipop (way faster than stock).

The white sheet bordering the setup is there to cover the gap that is not covered by the black panel. This is because the Palio dashboard is curved and the panel is straight.

Following pic shows what the knobs do. The knobs rotate endlessly, and also have a center push button.

Using an Android Smartphone as a Head-Unit-knobs.jpg

More details later. Maybe I'll make a video showing how the knobs work.
Cheers!!

-Vimal

datvichrox2 · 19th February 2016, 12:33

Installing the Android phone at the location of the head-unit

Materials:

A good phone back cover, preferably made out of metal. I used an aluminum based back cover for the redmi.
Door magnets
Small machine screws with nuts
Couple of oversized nuts , to be used as spacers.

Using an Android Smartphone as a Head-Unit-back-cover.jpg

ALWAYS DISCONNECT THE NEGATIVE TERMINAL OF THE CAR BATTERY WHEN WORKING ON THE CAR. KEEP A FIRE EXTINGUISHER HANDY.

Initially, I made a cardboard cut-out to place in front of the head-unit, to visualize the space requirements and to mark where the door magnets have to be placed. What is important is to mark a straight line which will depict the new plane that we are going to create in front of the dashboard.

Using an Android Smartphone as a Head-Unit-cardboard-cutout.jpg

Take out the AC panel from the car so that you can get to work on it. In Palio, you can pry out the bottom most panel which contains the temperature control knobs. This will expose two screws which are holding the AC panel. After unscrewing them, you will have to again pry out the AC panel from the top, where it is held by clips.

On the straight line that was marked earlier, place the door magnets at equal distances and mark the holes that need to be drilled. Use screws with nuts, to secure the magnets to the AC Panel.

Next, we have to place the mobile phone holder on the center magnet, and mark the holes on them as well. The idea is to use the metal pieces that come with the door magnets to secure the phone holder to the center magnet. This step requires putting the AC panel back in the car to make sure the phone holder is at the center of the setup.

In the end, you will have something like this. This will hold the phone securely and you can drive without fear of anything coming apart.

Using an Android Smartphone as a Head-Unit-f1.jpg

Using an Android Smartphone as a Head-Unit-f2.jpg

Using an Android Smartphone as a Head-Unit-finishedfront.jpg

Using an Android Smartphone as a Head-Unit-finishedback.jpg

Using an Android Smartphone as a Head-Unit-finishedinstalled.jpg

The point of using magnets on a straight line is because the front-panel which has the knobs will be attached using these magnets.

-Vimal

knp · 19th February 2016, 13:02

wow.. awesome work Vimal. Waiting for video now and I will try something similar as I have been experimenting on this area for a while.

AtheK · 19th February 2016, 13:23

Brilliantly done, congratulations on such a neat setup, looks very professional.

speedmunster · 19th February 2016, 13:46

Very neatly executed. But, where is the old head unit?

Ruchitya · 19th February 2016, 17:22

Looks neat! Although at that screen size and low placement, I hope you are using voice navigation more than looking at the actual map. You would have to take your eyes off the road quite a bit to see the map, w.r.t. where its placed right now.
I had a similar idea, but to implement driver monitoring using a phone (heart rate, drowsiness, etc.). Lack of Google APIs for the same is a hindrance though.
I'd love to know how you are reading the car's technical data as well, please? What other data have you been able to receive as of now?

StallionAmit · 19th February 2016, 21:16

Exceptional work my friend, this indeed is a gem of a work and i can just imagine the amount of satisfaction you will derive from this.

nimit3105 · 19th February 2016, 22:44

Great setup, Mate. I would also recommend you to check out the "Automate" app for Android which is sort of a launcher that emulates the Android Auto layout. I use it quite a lot while driving for Maps/Music with the phone connected via Aux.

Chethan B G · 19th February 2016, 22:50

Very smart! Thanks for sharing.

You can actually have separate contact number for the car. That would be awesome.

a4anurag · 19th February 2016, 22:55

Quote:

Originally Posted by datvichrox2

Some pictures of the install

Excellent buddy. Hats off for all the learning and modification. Do post some day time pictures.

Answering calls would be great with this setup.

Quote:

Originally Posted by Chethan B G

You can actually have separate contact number for the car. That would be awesome.

kvsingh13 · 20th February 2016, 02:50

That is very professional looking. Kudos to you for doing it all from scratch. It looks so fine.

invidious · 20th February 2016, 10:04

After reading the first post I thought "Has to be some chap in Bangalore". I then checked the location

Excellent job - looks professionally done. You can probably spin this off as a business model with a plethora of older cars lacking modern HUs.

GKMahajan · 20th February 2016, 10:19

Dear datvichrocks2,

"I am impressed" is an understatement!
You deserve full 5 stars!

Just a stupid question - is this really plug-and-play?
If yes, you should patent it and offer to end users!
I agree that you have most probably done this as a hobby, but still... just my two bits!

Girish Mahajan

Petrolhead007 · 20th February 2016, 13:15

I am speechless, that's quite a professional install. I have installed Blaupunkt New Jersy on my Ford Fiesta 1.6 about a week back, I can tell with confidence that your install quality is much superior than mine, which was done at Sachin's Autoshop at Koramangala, supposed to be professionals. Congratulations for the new HU.

19th February 2016, 12:03	#1
datvichrox2 BHPian Join Date: Dec 2009 Location: Bangalore Posts: 110 Thanked: 294 Times	Using an Android Smartphone as a Head-Unit This was going to be a proof of concept of an idea that has been gnawing at me for a while. Its a hobby project that I did on my 2004 Palio 1.2 and I am happy with the way it has turned out. What I have in my car currently, this came with the car when I bought it used in 2008: Blaupunkt LongBeach c31 - cassette player , with aux input at the rear Blaupunkt 542 speakers (4) What I will have after this mod: Android Phone which serves as audio head unit and navigator (The Blaupunkt components will remain as it is) If this works, it will make my 10 year old car-cassette player useful in 2016 as well. Android phones can pretty much provide all the major functionality that is needed in a car - Audio Playback and Navigation. Even a cheap Android phone can replace a car head unit. It can also be made to respond to voice commands. Installing a phone/tablet in a car has been done before - lookup Android Nexus7 in-car installations and many examples on t-bhp itself. How this project differs is in the way inputs are handled. I hate interacting with touch screens in car entertainment systems - it takes a while to get things done because of the small buttons and menus and this can be distracting during driving. The major features should be easily accessed and controlled with as few interactions as possible and with dedicated hardware controls. This is where the Arduino Uno comes in. I will be adding hardware buttons, rotary encoders and program the Arduino Uno to respond to them. The Arduino Uno will communicate with the Android phone using bluetooth. The Arduino Uno tells the phone which button was pressed or which knob was turned and in which direction. The Phone can respond accordingly - this requires some custom programming to listen to specific commands over bluetooth, mentioned below. A custom Android service in the phone will be listening solely to the Arduino Uno via bluetooth and based on the code that the Arduino sends, will perform actions on the Android phone. Some of the actions that the custom Android app will trigger are as follows: Launch Maps Launch Music Player Reduce / Increase Volume (this will be sent to the head unit) Play Next Song Play Prev Song Pause/Play The car cassette player which is currently installed will be put into AUX mode permanently and will take its audio input from the Android phone. It will continue to provide amplification and controlling of the car speakers. That will be its sole purpose. Advantages of this system: Can be updated easily by using custom apps on the Android and custom code on the Arduino. Any car headunit can be used as long as it has AUX-input. The car's ECU system can be read and displayed on the Android phone. If there's a problem with the car, you would know immediately. Access to google maps and apps. It can have its own sim card and data connection. I could send a remote message to the car and it could be programmed to respond with its current location. Can be extended to support steering wheel controls as well. Disadvantages of this system: It is a complete D-I-Y (do-it-yourself) project and will take a long time to complete. I started this around 6 months ago and spend whatever time I get in the weekends. It needs hardware customization as well, if you want it to be a plush-fit. This is needed to make it look professional. Need to learn Android programming Need to learn Arduino programming Need to acquire Soldering skills and basic electronics design The reason I chose a phone over a tablet, is because of the space available in the car. It is a single DIN space and I cannot put in a tablet as that would require a double DIN space. Here is a picture depicting the components involved and how the communication happens between the devices:
	(35) Thanks

19th February 2016, 12:32	#2
datvichrox2 BHPian Join Date: Dec 2009 Location: Bangalore Posts: 110 Thanked: 294 Times	re: Using an Android Smartphone as a Head-Unit Some pictures of the install: With the screen off. Tasker turns off the screen 7 secs after the phone loses power. An app called DeepSleep Battery saver makes sure I don't loose too much battery when I don't use the car. So far I have seen that the battery drops at-most 1% when left overnight. The Home screen. This is actually a really large custom Widget made using UCCW (available on google play). Music - opens poweramp Maps - opens gmaps CarMode - still not functional, I am writing a custom app to talk to the Palio ECU and display some geeky stuff (since torque wont work ) PowerAmp music player. PowerAmp has good equalizer controls and my current cheap speakers never sounded better. Yet to find a good skin for landscape mode. What I like most about having an android phone in the car - Google Maps. Behind the acrylic panel - Arduino Uno fitted into the Palio clock slot, with all with wiring going through it, including aux, usb power and wiring for the knobs (rotary encoders). The black acrylic panel is held to the AC panel using 3 door magnets. Driven more than 600 kms with this at highway speeds. No issues. The phone is a Xiaomi Redmi 1s, running Mokee Custom Rom Lollipop (way faster than stock). The white sheet bordering the setup is there to cover the gap that is not covered by the black panel. This is because the Palio dashboard is curved and the panel is straight. Following pic shows what the knobs do. The knobs rotate endlessly, and also have a center push button. More details later. Maybe I'll make a video showing how the knobs work. Cheers!! -Vimal Last edited by datvichrox2 : 19th February 2016 at 12:47. Reason: Another Pic
	(85) Thanks

19th February 2016, 12:33	#3
datvichrox2 BHPian Join Date: Dec 2009 Location: Bangalore Posts: 110 Thanked: 294 Times	Installing the Android phone at the location of the head-unit Materials: A good phone back cover, preferably made out of metal. I used an aluminum based back cover for the redmi. Door magnets Small machine screws with nuts Couple of oversized nuts , to be used as spacers. ALWAYS DISCONNECT THE NEGATIVE TERMINAL OF THE CAR BATTERY WHEN WORKING ON THE CAR. KEEP A FIRE EXTINGUISHER HANDY. Initially, I made a cardboard cut-out to place in front of the head-unit, to visualize the space requirements and to mark where the door magnets have to be placed. What is important is to mark a straight line which will depict the new plane that we are going to create in front of the dashboard. Take out the AC panel from the car so that you can get to work on it. In Palio, you can pry out the bottom most panel which contains the temperature control knobs. This will expose two screws which are holding the AC panel. After unscrewing them, you will have to again pry out the AC panel from the top, where it is held by clips. On the straight line that was marked earlier, place the door magnets at equal distances and mark the holes that need to be drilled. Use screws with nuts, to secure the magnets to the AC Panel. Next, we have to place the mobile phone holder on the center magnet, and mark the holes on them as well. The idea is to use the metal pieces that come with the door magnets to secure the phone holder to the center magnet. This step requires putting the AC panel back in the car to make sure the phone holder is at the center of the setup. In the end, you will have something like this. This will hold the phone securely and you can drive without fear of anything coming apart. The point of using magnets on a straight line is because the front-panel which has the knobs will be attached using these magnets. -Vimal Last edited by GTO : 22nd February 2016 at 09:53. Reason: Adding your latest update to the opening page itself :)
	(20) Thanks

19th February 2016, 13:02	#4
knp BHPian Join Date: May 2006 Location: bangalore Posts: 241 Thanked: 42 Times	Re: Using an Android Smartphone as a Head-Unit wow.. awesome work Vimal. Waiting for video now and I will try something similar as I have been experimenting on this area for a while.
	() Thanks

19th February 2016, 13:23	#5
AtheK Distinguished - BHPian Join Date: Jun 2014 Location: Bangalore Posts: 2,040 Thanked: 8,428 Times View My Garage	Re: Using an Android Smartphone as a Head-Unit Brilliantly done, congratulations on such a neat setup, looks very professional.
	() Thanks

19th February 2016, 13:46	#6
speedmunster BHPian Join Date: Apr 2009 Location: Hyderabad Posts: 218 Thanked: 327 Times	Re: Using an Android Smartphone as a Head-Unit Very neatly executed. But, where is the old head unit?
	() Thanks

19th February 2016, 17:22	#7
Ruchitya BHPian Join Date: Apr 2014 Location: Austin, BLR Posts: 88 Thanked: 123 Times	Re: Using an Android Smartphone as a Head-Unit Looks neat! Although at that screen size and low placement, I hope you are using voice navigation more than looking at the actual map. You would have to take your eyes off the road quite a bit to see the map, w.r.t. where its placed right now. I had a similar idea, but to implement driver monitoring using a phone (heart rate, drowsiness, etc.). Lack of Google APIs for the same is a hindrance though. I'd love to know how you are reading the car's technical data as well, please? What other data have you been able to receive as of now?
	(1) Thanks

19th February 2016, 21:16	#8
StallionAmit BHPian Join Date: Jun 2015 Location: Kolkata Posts: 199 Thanked: 380 Times	Re: Using an Android Smartphone as a Head-Unit Exceptional work my friend, this indeed is a gem of a work and i can just imagine the amount of satisfaction you will derive from this.
	() Thanks

19th February 2016, 22:44	#9
nimit3105 BHPian Join Date: Nov 2015 Location: Mumbai Posts: 103 Thanked: 154 Times	Re: Using an Android Smartphone as a Head-Unit Great setup, Mate. I would also recommend you to check out the "Automate" app for Android which is sort of a launcher that emulates the Android Auto layout. I use it quite a lot while driving for Maps/Music with the phone connected via Aux.
	(1) Thanks

19th February 2016, 22:50	#10
Chethan B G Senior - BHPian Join Date: Mar 2010 Location: Bangalore Posts: 1,657 Thanked: 2,057 Times View My Garage	Re: Using an Android Smartphone as a Head-Unit Very smart! Thanks for sharing. You can actually have separate contact number for the car. That would be awesome.
	() Thanks

20th February 2016, 02:50	#12
kvsingh13 BHPian Join Date: Dec 2015 Location: New Delhi Posts: 46 Thanked: 24 Times	Re: Using an Android Smartphone as a Head-Unit That is very professional looking. Kudos to you for doing it all from scratch. It looks so fine.
	() Thanks

20th February 2016, 10:04	#13
invidious BHPian Join Date: Sep 2009 Location: Bombay Posts: 845 Thanked: 1,226 Times	Re: Using an Android Smartphone as a Head-Unit After reading the first post I thought "Has to be some chap in Bangalore". I then checked the location Excellent job - looks professionally done. You can probably spin this off as a business model with a plethora of older cars lacking modern HUs.
	(1) Thanks

20th February 2016, 10:19	#14
GKMahajan BHPian Join Date: Sep 2015 Location: Pune/Mumbai Posts: 609 Thanked: 874 Times	Re: Using an Android Smartphone as a Head-Unit Dear datvichrocks2, "I am impressed" is an understatement! You deserve full 5 stars! Just a stupid question - is this really plug-and-play? If yes, you should patent it and offer to end users! I agree that you have most probably done this as a hobby, but still... just my two bits! Girish Mahajan
	(1) Thanks

20th February 2016, 13:15	#15
Petrolhead007 Newbie Join Date: Aug 2015 Location: Bangalore Posts: 11 Thanked: 19 Times	Re: Using an Android Smartphone as a Head-Unit I am speechless, that's quite a professional install. I have installed Blaupunkt New Jersy on my Ford Fiesta 1.6 about a week back, I can tell with confidence that your install quality is much superior than mine, which was done at Sachin's Autoshop at Koramangala, supposed to be professionals. Congratulations for the new HU.
	(1) Thanks