Raspberry Pi Head Unit

Just updating this project, as it has been a while!

I have all the parts required to make exactly what I need.

I've drilled a few holes where required to allow for cables to be passed from the head unit, to the display area, and also to tap power to the Mauseberry circuit.

Before proceeding, however, I have a few wiring issues to fathom.

I've recently replaced the stalks on the steering wheel as my headlights would come on while indicating right, and that issue has been sorted.

Another is the brake lights seemingly sticking on, so hoping the switch behind the brake pedal just needs replacing.

Intermittent cabin lights are also an issue.

My favourite quirk has to be that when wipers are on and the driver window is being closed turning the steering wheel right can put the window back down, ha ha ha!

I'm hoping to find whatever short is causing these soon; once I have faith in my wiring I'll be able to add the head unit.

Over two months after i placed my order, i have finally received confirmation my Mausberry power circuit is on its way!

I've seen around a dozen emails querying it's whereabouts unanswered in 2020 alone, so I really thought I'd been had, but really looking forward to getting it and getting this in the car.

The 7" screen fits the sat nav cluster, the pcb just needs the corners cutting off to allow it to fit cleanly behind the screen.

The Pi and software work great.

I need to pick up a powered hub hub just to make sure there's adequate power for all devices and ensure I have enough ports for:

The touchscreen usb cable

The phone USB cable

The Bluetooth dongle

The 64gb memory card with music on

The USB microphone for handfree calls

The keyboard dongle for the little keyboard I've been using to enter details (not necessary for driving but handy for my son's input when passenger ha ha)

Currently this project is awaiting one part before I can install it into my car - the Mauseberry power switch. 

I've got the 7" screen fitted and just needing a spot of hot glue to hold it in place.

The Pi is running the software as expected, and I have added a USB microphone for input and it's working like a charm.

Once the power switch board arrived it'll be a case of plugging in the Pi and wiring the board to the car's battery and ignition.

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!

http://raspi-ups.appspot.com/en/software.jsp?_utm_source=1-2-2

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.

Cheers!