I've seen some projects on the Internet about car media systems using a Raspberry Pi and I was thinking: I could make something like that for my own car. My idea is to let the Pi take over the function of the car stereo (including some additional features), while using/maintaining the space a standard car stereo uses. So I am not thinking about most of the “car computer” projects I've seen so far, as they are an addition to the car stereo.
The “additional features” I am talking about:
- GPS navigation
- Digital storage of all of my music
- Possibility to play music from smart phone (probably via Blue-tooth)
- Eventually I would like to see some of the OBD-information (On Board Diagnostics) on the screen, although that has a lower priority.
- And maybe more.
- The current car stereo doesn't allow me to play music from my phone as it has no Blue-tooth or 3.5mm audio-jack connection.
- The current car stereo doesn't have a navigation system. Although it isn't a problem to use a separate navigation system, it would be less hassle and safer to have an in-build navigation. Less hassle because there are no separate parts to forget or break, and safer because the separate navigation system is always attached to the inside of the windscreen, taking a fair amount of visibility away.
- Buying a new stereo for my car will cost a lot more money than “building your own” and apart from that there aren't many car stereo's that fit most of my requirements, while still maintaining to the single din layout that fits my car. Unless you talk about those retractable flip-up screens, but those take away the possibility to reach about half the buttons on the center-console, including the hazard-light button.
- I hate to have most of my cd-collection lying in the car and being exposed to high/low temperatures, sunlight, robbery, etc.
- As an Automotive Engineering student I am interested in my vehicles information, and it would be extremely awesome to see live OBD-information while driving (without having my enormous 17” gaming-laptop on the passenger seat).
There are some questions I have, that maybe somebody here can help answering/figuring out. They are marked in red.
Thanks in advance for any help/interest in the project.
1. Raspberry Pi
First of all of course there is the RPi, I thought it would be best to just start with an RPi B+.
As this project is based on a single din radio, the largest screen possible is probably a 3.5” screen. As a keyboard/mouse in the car is not really what I want, I am looking into touchscreens. I've seen numerous 3.5” touchscreens. Can somebody tell me the probability (and difficulty) of getting these setups to work:
(as I couldn't copy a table into the text here, I made a screenshot. the links below are in the same order as the table)
2. Neosec Display
3. Arduino-based Display
4.1 Display with Touch Panel
4.2 Touch Panel Driver
Note: the price of the PiTFT is different than the added link, because I would order that via Adafruit's distibutor in the Netherlands, instead of via Adafruit itself.
The PiTFT (setup 1) and the Neosec (setup 2) both are probably easier/faster in getting working than the other setups. But the higher prices concern me, is it worth the price difference?
Is it possible/complicated to get setup 3 (with an PCB adapter for Arduino) working on a Raspberry instead of an Arduino?
I've seen this thread on this forum, setup 4 is based on the setup/idea used in that thread. With the difference that the display I listed is connected in an other way than the display in the thread. Again the question if it is possible/complicated to get this setup working on a Raspberry?
Are there any interesting alternatives that I haven't heard of?
3. GPS Navigation
For the navigation a GPS signal is needed, which my car doesn't have. I've found a GPS-module with antenna, which should take care of that. But I haven't found anything about the use of this GPS-module with a RPi. Can somebody say anything about using this module with a RPi? Apart from that I am wondering if the antenna could be placed inside the stereo space (and still maintain a good GPS connection), or that the antenna should be placed somewhere else for a better GPS connection.
4. Media player
I am thinking about playing music in all of the following ways:
- FLAC files from an in-built USB-stick
- The standard radio (FM) signal
- Music from my mobile phone (via Bluetooth)
In this case I think a 512GB USB-stick will have enough space to store all of my CD's, as I understand that FLAC-files usually use about half of the space a CD uses. So around 350Mb of FLAC-files per CD, which roughly means about 1400 CD's on a 512GB USB-stick. I don't come near that number of CD's, probably around 100-200. But as I was thinking of using the USB-stick as an in-built memory for other things (like the maps the navigation software uses), I am sure 512GB will be enough.
For the FM-signal I was thinking about using a FM-module and just connect it to the existing car antenna, as I've seen more people implement those FM-modules.
And for the music from my mobile phone I was thinking of using a bluetooth dongle.
The sound quality of the analog output of the RPi is said to be not great. I don't know much about sound, amplifiers, etc. and I am not an audiophile, but I would like to at least have the same sound quality as the standard car stereo now has. Would using an amplifier with the 3.5mm sound output of the RPi give me the sound I want or should I be better of looking at other sound output possibilities like a Behringer UCA? I've seen multiple tips on the internet about using those Behringer UCA's as RPi sound outputs, are they really worth the extra money compared to just using the RPi's analog sound output?
And regarding the amplifier: the standard stereo has a 4x45W amplifier. I thought I had found a nice amplifier that also had 4x45W output, but that one is powered by 12V AC, while a car battery puts out 12V DC. So it is probably easier to look for another amplifier. As I don't really know what to look for, are there any tips on what amplifiers I could/should use? Could I for example use a 4x25W amplifier (as I see some standard car stereo's use them as well) or amplifiers with any other output, or could that give any problems/poorer sound? Is there a minimum required sound output? And are there other factors to think about?
5. OBDII data
For the OBD data I was thinking of using a bluetooth OBDII scanner, as they use less space than scanners with USB-connection, I am already planning on using a bluetooth dongle (for the connection with my mobile phone) and a bluetooth version makes sure there is no need to place a USB cable between the OBDII-connection and the RPi.
As the idea is to replace the standard car stereo with the RPi, I am planning on placing the RPi and all of the hardware components in the same space a standard single din stereo uses. I am thinking of getting an old car stereo with the standardized connection in the back and just take out all the hardware inside and place the RPi and new hardware inside. The standard car stereo connection will be used to connect the power to the components, the sound to the speakers, the antenna th the FM-module, etc. The screen, an “external” USB connection and probably some buttons to navigate quickly through the different software (GPS, Mediaplayer, OBD, etc.) will be placed together with a self designed front on that old stereo casing. So when the project is finished it should be a real plug and play car stereo.As almost all components are very little and don't use much space, there will probably be no problem there. But can I expect problems or should I take precautions regarding the heat that comes of the RPi or some of the components?
7. Power Supply
For powering the RPi I am planning on using a standard USB car charger, and stripping it of its casing to use it inside the stereo casing. The power will then be going from the power pin on the casing connector to the USB charger, delivering 5V, 2.1A via USB to the RPi. Because I am planning on using a number of different components together with the RPi, if necessary I will use two USB chargers, to power other components without cutting to much of the RPi's power.
There is only one problem with the power supply: As you turn off a cars ignition, it immediately cuts power to the stereo. As that is probably not a good idea for a RPi, the RPi needs to get enough time to properly shut down. I've seen a solution for that problem, but they are sold out and rather expensive (as they push the total cost of the project up with roughly 10 to 20%). Are there any cheap alternatives (possibly DIY)?
As I don't have an RPi at this moment, I can't say much about the software/OS and I haven't looked deep into this. I don't have many requirements for the software/OS, except that it supports the different applications I want to use and it can cycle between them. Are there any interesting programs or operating systems that I should be aware of?