Project: Touchscreen Interface for car - Page 1
Forum section: electronics / projects

author: roundy
author_rank: Newbie
timestamp: April 17, 2012, 12:47:31 pm
content: I am planning on building an electric car. But funds are tight so before i buy all the expensive bits (batteries, motor, etc) i want to design and build my touchscreen interface. It is basically for telling you state of charge, instant power, voltage, current etc. Also I am going to build the motor controller so I would like to be able to tell controller to limit power output and do others things. The problem i have is I don't know where to start, what os to use or what board to use to have digital and analogue inputs and outputs. So to summarize I want it be practically instant on (<10s) and to basically work like an android or iphone app with functionality similar to the tesla model s screen. Can anybody help me out?

author: Psi
author_rank: Super Contributor
timestamp: April 17, 2012, 12:58:45 pm
content: One of the critical things to keep in mind when selecting a touchscreen lcd's for a car is that they need to be bright, very bright, if you want them usable during the daytime.

author: roundy
author_rank: Newbie
timestamp: April 17, 2012, 01:05:01 pm
content: Quote from: Psi on April 17, 2012, 12:58:45 pmThanks Psi, I was thinking along the lines of a 7" tablet screen? I'm really interested though in the os system and programming language. What os has a very short boot time? and what is the "best" language for driving large lcd screen with touch input and the inputs and outputs mentioned in the first post?

author: bobhaha
author_rank: Contributor
timestamp: April 17, 2012, 02:18:13 pm
content: Does itneedto be a large touch screen tablet?You can program an android app quite easily using Processing (http://processing.org/). Then communicate with your car with an arduino and blue tooth module.If you don't need as many IO pins try something like the attiny85 which can still be programmed via the arduino IDE.Just a thought / nudge in the right direction... Hope that helps-Adrian

author: Psi
author_rank: Super Contributor
timestamp: April 17, 2012, 02:34:39 pm
content: People have gone to extraordinary lengths to make their carpc lcd viewable in the daytimeHere's one where he removed the backlight and added lots of highpower leds and a watercooling blockhttp://hackaday.com/2007/01/31/watercooled-led-backlit-lcd/http://www.mp3car.com/lcd-display/43743-800x1280-narrowscreen-8.html

author: roundy
author_rank: Newbie
timestamp: April 17, 2012, 03:09:37 pm
content: Quote from: bobhaha on April 17, 2012, 02:18:13 pmThat's exactly the sort of info i'm looking for. So there would be no physical connection between my android tablet and the car and an arduino board with bluetooth module communicates with it?sounds good.can an android tablet with only a usb connection talk to an arduino board over usb and still control all the inputs outputs?What im really trying to say is can I change settings etc while driving as opposed to flashing the arduino every time. I want my arduino to drive my motor controller

author: roundy
author_rank: Newbie
timestamp: April 17, 2012, 03:16:31 pm
content: Quote from: Psi on April 17, 2012, 02:34:39 pmThats a pretty cool idea with the leds Psi i have to say. Thats for the links. I have a 10" Zenithink tablet at the moment and I can see it pretty good in the car even in bright sunlight. (although at full brightness it gets very hot after a while and locks up needing a reset so ill prob need some active cooling somehow)

author: bobhaha
author_rank: Contributor
timestamp: April 17, 2012, 03:58:27 pm
content: Yes of course.Output from the app on your tablet will be something like this..WS, 100, dir, L, GPS, onSo for example the arduino will read this code in and split it giving the variable wheel speed 100%, direction as left and turn the GPS on.Again that's an example... your code can work any way you want it to / find works.I don't have much experience with bluetooth communication, but I know it definitely can be done.The only problems I can see you running into, with a tablet is, if the tablet has internal bluetooth module and no USB ports then you might have to do some complex things to access rights to use the bluetooth with your app.-Adrian

author: sonicj
author_rank: Frequent Contributor
timestamp: April 18, 2012, 12:35:18 am
content: Quote from: Psi on April 17, 2012, 02:34:39 pmthis is much less of a challenge with a modern tablet display vs the lcds of 5 to 7 years ago.i just pulled the dash out of my car and the first thing that came to mind was "glass cockpit"! the dash consumes a huge chunk of real estate just to house a few switches & vents, trim out the passenger air bag and house the "traditional" instrument cluster (its 100% electrically driven on this car). replacing the instruments with a OBD2 dongle and android tablet wouldn't be too tough at all. integrating it without looking like crap is the toughest part. check outtorquefor viewing odb2 on android. pretty slick for $5!so yea, most higher end ev controllers are going to have CAN Bus, serial, ethernet, etc. you can pick data from.-sj

author: roundy
author_rank: Newbie
timestamp: April 18, 2012, 01:36:30 pm
content: Thanks guys for all your help. Finishing exams in three weeks so plan to start my project then. I'll prob start a new page describing and detailing my build so hope to hear from ye then