Posts: 32
Joined: Fri Sep 25, 2015 10:55 pm

First project- Need some advice...

Mon Nov 30, 2015 3:20 pm

My first Raspberry Pi project is born out of necessity, and I've never attempted anything quite like this before. I'm currently in the planning phase. The dash lights in my car have burned out, and my options are to either buy ~$30 (or more) worth of parts to fix it or install a cheap aftermarket solution --OR-- to build my own. I think using a Pi Zero for this project would cost about the same (and it's worth it if it's a little more anyway). Objective would be to power everything from the car battery. I would want it to wait 3 seconds after detecting current to the headlights before energizing the Pi. This is to protect it from turning on while the car is starting- so if there is a better way to do this, I'm open. I would need a strip of LED's that are kind of bright and variable color (The strip would uniform color but I could change it on the fly, probably with a switch or button, or programmatically- I'd prefer to be able to use a PBNO to trigger it to change). I'd also like to be able to vary the intensity, probably with another PBNO- I like the idea of digital controls. I'd like to use a photosensor (perhaps stuck to the back of the mirror) to automatically turn on the lights. Can anyone recommend what parts I need and where to get them? Here's what I am envisioning:
-Pi Zero
-Enclosure for the Pi
-GPIO header
-4GB Micro SD card
-Power supply for Pi
-Fuse for Pi power supply
-varying color and intensity LED strip- would also need a low-profile enclosure or something with a backing so the light is directed to my gauges and I'm not looking straight into a strip of LED's when I check my speed
-2 pushbuttons- will need suggestions for appearance and some kind of enclosure, perhaps each is two switches, so we can go back without having to cycle through from the beginning- still haven't decided yet.
-light sensor that can withstand a fair amount of heat- Being mounted to the back of the mirror and being constantly exposed to sunlight coming through the windshield seems like it would need to be a rugged component.

Also, I need to know what the best way would be to power the LED's- Should this come through the Pi, or should the Pi act as a gate to switch on the LED's and provide a control mechanism- Should it be a power supply or just a controller? I'm planning to wire directly to the battery for any power needs- no cig lighter plugs. I'm thinking the hardware will be the most difficult part of the project- The scripting should be pretty easy.

So in a nutshell, I'm looking to build a project, probably with a Pi Zero, that will automatically turn on dash lights and allow me to customize the appearance for brightness and color, using pushbuttons on the GPIO's to do this- I want to make sure I have failsafes, so if something does go wrong, I can kill the lights, but I can just put a killswitch in line with the Pi power to accomplish this. Knowing me, I'll probably add a button down the road to save settings to the Pi.

My plan is to start with getting the Pi physically and logically working- that means getting the GPIO header installed, booting to Raspbian, then powering it directly from the car, getting the lights to come on at all, and then moving on to get the light sensor to turn the lights on, then the intensity controls working, then the color controls. I plan on using button presses on the GPIO to trigger scripts on the Pi to run the various functions.

So, with all that, I'm open to suggestions- I live in Pennsylvania in the US, about an hour from MicroCenter (Only store currently selling PI Zero and accessories), and I shop online as well for components. I have kids who will be very interested in working on the project, so it will create an educational opportunity as well as we get each piece working.

I have to deal with the first question: how/when can I get a Pi Zero? Microcenter is sold out and they are not on Amazon, plus I've read that they are sold out of the MagPi 40.
So far, I have created some things with the RPi2B- A couple of HTPC's and a content filtering proxy server, but these are mostly software-focused. This project will be more of a hardware and interfacing project. If I can't get a Pi Zero right away, I figure I can always 'borrow' one of my 2B's, which use a 2.5A power supply (Pi Zero accessory kits generally come with a 2A supply) and then I can swap in a Zero when available.

Sorry for the long post- just trying to get started and cover as many details as possible.
Can anyone recommend resources, brands, or even specific parts?
I appreciate any advice.

Posts: 8
Joined: Sat Jan 30, 2016 4:33 am

Re: First project- Need some advice...

Sat Jan 30, 2016 5:24 am

im looking to do something like this as well. Id like some red, green, and blue LEDs and have the Pi scroll through the colors or at least vary the voltage to the 3 colors of LEDs to vary the color at will to change the colors of the interior

Posts: 131
Joined: Mon Jan 18, 2016 3:45 pm

Re: First project- Need some advice...

Thu Feb 11, 2016 6:42 pm

Probably better off using a 7" screen for your dash. Then you can display anything you want. tach, speedometer, water temp, oil pressure, blinkers, heck brake temp even.... But $30, wow, I don't think I can fix my 69 beetle dash that cheap.
Voltage regulator will protect you from headlight and engine start. Best thing is the pi can go around those stupid breathalyzer machines. and send anything you want to those stupid state inspectors. Plenty of room in the hole made when you remove the airbag death trap to install it.

Posts: 114
Joined: Sun Feb 23, 2014 9:51 pm
Location: Portland, Oregon USA
Contact: Yahoo Messenger

Re: First project- Need some advice...

Sat Feb 13, 2016 7:24 am

Make sure you use a power supply intended for cars. When the starter turns off it can kick back a couple hundred volts, same with the ignition coils not to mention the RF from the spark plug wires.

As for light color try a blue green, it helps with still being able to see outside at night.

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