Bringing Bluetooth/wifi streaming and USB/SD Card music to my auld car via the head unit's CD Changer port
After the disappointment of finding the Official Pi Touchscreen wouldn't fit the original sat nav cluster I picked up for my car I picked up a 7" HDMI touchscreen from eBay.
Out of the box it also didn't fit, but with a bit of work it is almost fitting nicely.
I removed the pcb from behind the screen to allow the screen to slot in a bit easier, and used some cutters to remove some of the offending plastic from its way.
I'm next going to cut down the pcb to allow it to fit.
Once that is done it's time to fit it 😎
One of the main issues I have come across with planning a Pi-based install has been power-based, and wondering what the best way to trigger a safe shutdown and avoid corruption to the OS.
There are boards that allow for a constant powering directly from the battery that monitor the ignition pin and send a command to the Pi to trigger a safe shutdown when the power goes, and I aim to replicate that function using an arduino. Kinda.
The Pi will be connected to the Battery directly using a fused, 5v connection. The arduino will be powered by the 12v ignition power, and both devices will be connected together via their serial pins.
The plan is to have the Arduino send a data packet every five seconds, and the Pi will receive it via a Python script that runs on startup.
If the Pi does not receive data for 10 seconds, this will be due to the Arduino being powered off by the engine being turned off. This can then trigger a safe shutdown of the Pi.
In order to reset the Pi on startup I'd been to incorporate a switch in the wiring to the Pi, but I would love to think of a solution to allow the Pi to just power up when the engine is started.
Recently I was researching some options to reignite my Pi Car idea, and I came across the OpenAuto project, which emulates an android head unit. This intrigued me; it had all the capabilities I was needing, and it was achievable with the parts I had to hand, give or take a few missing items.
There is an Open Auto pro image available for a nominal fee, but there's also a free, open-source option called crankshaft. This adds a friendly GUI for the Open Auto project, and seems to work well.
My currently car, a 2006 Clio Mk3, has a simple head unit and a small clock pod in the centre of the dash; there was a sat nav version which came with a larger pod for a screen, which would be a a great place to mount a Pi Touchscreen.
I have picked up this pod from a scrapped vehicle, and am going to use a dremel to remove some clips which prevent it from fitting in. Once fitted I will be able to put this pod in the place of the old clock, and move the old clock down below the centre console.
I will then be able to retain all currently head unit functionality and feed my new Pi based system into it via the aux in I added.
It's been a long time since I've looked at this project; I currently have a DAB Radio/Bluetooth board which I tether to my phone and it seems to do the trick for me for now.
That being said, I'd still like something that could be buried in the glove box and a nice little touchscreen would allow control for music.
In another project (my sample pad controller and electric drum module) ibe changed my plan of attack, and it has left me with a M0-based board from dfrobot and a music playing shield, complete with SD card slot.
Combining this little music player with a small Nextion touchscreen I have (uses software serial to communicate) and an esp8266 to allow a connection to my phone and perhaps an FTP server to drop music onto the SD card and that could leave me with a really handy little player.
If I built a small three channel line mixer I'd be able to have this player, my dab radio (which I use for hands-free calling) and a spare aux in for passengers to use.
This could be fun!
I'm going to eb hopefully getting my teeth back into this project after a while on the shelf.
One thing I was dubious on was how to handle the shutting down of the Pi safely when the car is switched off without causing corruption in the filesystem.
One method I am interested in is making the filesystem read only; If i can setup a read only system nothing will need to be saved during a shitdown sequence and will therefore protect it during sudden powerless.
I've recently set up a bank of Raspberry Pi A+ boards at work to handle playing videos on our foyer screens in our buildings and I am using MP4Museum to do so.
This has nailed the read only filesystem, so would love to build something like this for my project.
Just a quick post to share this link that uses an USB Powerbank as a UPS-style system, using a network switch to simulate the power outage (when the power is cut to the Pi and the Network switch the network connection goes down and the Pi detects it).
I could modify this to trigger a safe shutdown when the car is switched off. If there's a way to do it without the network switch that would be bloody marvellous!
So... I've finally settled on what I'm going to do with this.
I've recently made a music player for my partner as a little home made Christmas present. It's great; runs RuneAudio, has a memory stick full of her favourite albums, has Airplay receiver capabilities, and is generally a great little system.
I'd like to add that to my car; the only thing to sort out now is how to power it and switch it on/off with the car's ignition.
I have been thinking and rethinking my approach to this project for quite some time. I had always thought about using a Pi for it, as it is what I am used to playing around with, can have Bluetooth/WiFi added, could be hidden in the glove box etc.
While that may still be the long term goal I'm thinking about trying a somewhat different aoproach to get a simple system up and running...
I was was recently updating our media devices at home (one Android box and two Amazon Firesticks); we use Kodi, with the Paradox wizard install. Whilst looking through the builds I noticed that there was now a 'Music Build'. The description said it was tailored for in-car and audio streaming etc.
I stuck it on my phone and had a look at it; it seems great, has plenty of music add-ons, but is dependent on a WiFi connection.
It was at this point I started pondering... What if I use this approach? I could get an old handset, add a beefy microSD card for storing music, set it as a hotspot (to allow other devices to connect to it), and enable Airplay and the web interfaces to allow control from the passengers.
I could even go as far as adding a scheduler app to run Kodi on startup and turn the phone on/off when power is applied to the phone (by the car being started).
Definitely a good example to get me started.
So - need to investigate what to use to monitor the state of the power antenna!