Carputer Build - Page 1
Forum section: electronics / projects

author: ptodorov
author_rank: Contributor
timestamp: January 16, 2014, 05:12:03 pm
content: Hi everybody! Newbie here.I want to share with you my experiences building a carputer.Basically I wanted to put a computer in my car and be able to do all the things a high end head unit can do and some more.I've found these cases that are standard double din height, have touch screen monitor, some buttons and ports on the frontand have enough space inside to mount a Mini-ATX motherboard. This is similar to what I bought but mine had a touch screen:http://www.ebay.co.uk/itm/Bybyte-Black-Box-N-Double-DIN-Car-PC-Carputer-Enclosure-/200424885277?pt=US_Computer_Cases&hash=item2eaa410c1dFor powering the motherboard I've got one of these DC to DC PSU's that can plug in directly into the ATX conector:http://www.ebay.co.uk/itm/M3-ATX-HV-95W-6-34v-Automotive-DC-DC-Car-PC-Carputer-PSU-M350-BBX-1-Mini-ITX-/160727371462?pt=PCA_UPS&hash=item256c190ec6The nice thing about these is that they have a sense wire to the ignition that turns on/off the computer.For the GPS and wireless capability I've got 2 usb dongles with an external antennas.I ran 2 coaxial cables to the top of the dash for a better reception. I've also got a rear view camerabecause the monitor had the ability to switch inputs when a voltage is applied to a sense wire connected tothe white reverse taillight.For the music I decided to be cheap and bought the cheapest motorcycle amplifier I could find. It's kinda like this one:http://www.ebay.co.uk/itm/500W-Motorcycle-Car-2-Channel-Amplifier-mp3-amp-YL2-/260912375445?pt=UK_AudioTVElectronics_HomeAudioHiFi_Amplifiers&hash=item3cbf96e695WHAT WAS I THINKINGI didn't need to look at the dash any more to know the rpm of the car. The buzzfrom the engine coming from the speakers was louder than the music.Anyway. I've decided I wanted to be able to control headlights, blinkers and doors locking/unlocking from the PC.Being a programmer I've decided to go the easy way and got an Aruduino and some relays and bodge hack them togetherwith a horrible mess of wires. Now almost half a year later after discovering EEVBlog and the engineering community here Imust say I'm ashamed at what I've doneExcept the relays I've also added a remote to be able to lock/unlock the doors since the original one that came with the car didn't work.For the last 5-6 months everything ran fairly smoothly with a few glitches and bugs. But a few weeks ago all hell broke loosewhile I was driving. Suddenly left and right blinkers started flashing, the headlights started blinking and doors kept locking and unlocking.This kept happening for a good 30 seconds. Fortunately there were no other cars around me. Also when the winter came the arduino started draining the battery more noticeably, after leaving the car for several days it didn't start with the first turn of the key even trough I'm putting the MCU in sleep and waking it on an interrupt from the remote control. The battery drain was 250mA and after I diconected everything I've done from the car it drop down to 120mA.Even trough I wouldn't call this project a success (not by a long shot) I've had a lot of fun doing it and I have learned a lot of new stuff.After watching a ton of Dave's videos and lurking here I am inspired on doing the control of the car properly this year, on a purpose designed PCB.

author: crc64Error
author_rank: Newbie
timestamp: January 20, 2014, 03:11:08 am
content: Hey, this is awesome. And though you had a few failures, complete success would be boring. I am also in the process of putting a similar project in my car. But here are a few things you might want to look into adding to your system once you get the bugs worked out.OBDII-TTL Adapter to Arduino to PChttp://www.amazon.com/Zhangminivy-OBDII-TTL-Adapter/dp/B00BMIZL2QSolar Battery Tenderhttp://www.amazon.com/Battery-Tender-021-1163-Solar-Maintainer/dp/B004Q83TGOA good ground loop isolation circuit, to get rid of the hum.Not sure where to check first for the blinking lights and door locks issue, but good luck.

author: ptodorov
author_rank: Contributor
timestamp: January 20, 2014, 06:56:19 pm
content: ThanksThe OBD kit was exactly what I was looking for.Originally I bought a standard can bus shieldfrom sparkfun but it turned out that there are severalcommunication protocols and the one I've got is forcars past 2005.For the battery problem I'll try to better powermanagement in the circuit next time. Just usinga voltage regulator isn't going to do it. But a solarcharger is a good idea.For the grounding I plan to use the antenna connectionas in car stereos.As for the random blinking issue maybe it was becausethe wiring and overall build was messy and obviouslywasn't "automotive grade"

author: calexanian
author_rank: Super Contributor
timestamp: January 21, 2014, 01:28:33 am
content: I like the LCARS Star Trek theme.. I will forward it to Brent Spiner and Rick Berman!

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: January 21, 2014, 02:41:50 am
content: Nice project, I just found this eevblog recently myself and have learned a lot in a short time. I was wondering if you can display data on that lcd in the last picture, it's displaying 19:25 22c, from your carputer? I think some external sensors would be great too. Something to give you windspeed and direction. A 360 degree swivel cam, with a good optical zoom to indentity road hazards, maybe with infrared to see animals at night. Also if the camera had enough resolution to take images and video. Also could be used to monitor the car when left unattended. There's a lot that can be done.

author: ptodorov
author_rank: Contributor
timestamp: January 21, 2014, 09:23:02 am
content: Quote from: calexanian on January 21, 2014, 01:28:33 amNiceIf they're willing to share me the enterprise-d helm and ops consoles I'll be happy to rip the dashfrom my car and put themQuote from: GiskardReventlov on January 21, 2014, 02:41:50 amNo it's the standard car functionality on the display. Originally I was going to replace it and even got the right sized lcd for there,but that display shows fuel consumption data, witch unfortunately wasn't available from the obd on the car. After some diggingit turned out that the Denso computer system on the car was locked down pretty tight and last time I checked (several months ago)only one company claimed that they've cracked it. So I gave up there and didn't replaced it. Now after some time of lurking in thisforum I fell pretty confident to try to reverse engineer the signals going to that panel and try decoding them.As for the sensors I'll be definitely putting some for version 2I'm thinking about an accelerometer that may record potholes andalert me the next time the car approaches them, also an index of all the police cameras in the country (the police here are requiredto publish their locations monthly online) and alert upon approaching one. Wind speed will be tricky when the car moves, maybethe only thing I can measure is the wind speed entering the front of the car at the radiator. Currently I'm usingwww.worldweatheronline.comto query information about the weather at my location. They also give nearest populated area andpopulation count witch is nice. I've also outputted on the screen all of the the gps data like elevation, climb rate, speed, latitude andlongitude. Putting a camera is a great idea, but I'm not sure where to mount it without looking ugly or getting in the way. I've alsowanted to put a distance sensor in front of the car and calculate if the speed and rate of change of the speed is going to result in acollision, but I couldn't find long range distance sensor at a reasonable price. The ultrasonic ones are only good at several meters andthe laser ones cost a lot. If anyone knows a cheap solution for measuring distance (0-70m) it would be greatly appreciated.

author: calexanian
author_rank: Super Contributor
timestamp: January 21, 2014, 04:01:32 pm
content: Quote from: ptodorov on January 21, 2014, 09:23:02 amThere was actually a Crowd funding program to take the bridge from the star trek experience in Las Vegas and open it as a exhibit in San Diego I believe. I saw Brent and Mr. Berman in LA at a charity event a few months ago. Frakes, Gates, Marina, and Dorn were there. Even Crosby (Tasha Yar) was there. Mr Berman is busy traveling the world. Brent is getting a one man show off the ground of just him talking about life. I hear its really good. He did one show is Portland and is planning more. All nice people. I had met Levar Burton some time before. Its a shame. If Paramount did not have their heads up their asses we would still freaking have the show and movies! Its ALL!!!!! Paramounts fault evidential.

author: bbjk7
author_rank: Contributor
timestamp: January 21, 2014, 11:35:55 pm
content: Love this post, exactly the sort of thing I envisioned for my 2004 corolla sportivo. trouble is the OBD protocol is rather rare and I haven't seen anything other than the official "techstream" software connect to it, and only using the official toyota obd cable as well, even after trawling through a dozen forums from people looking for the same thing :/What are the specs of the carputer? Processor? RAM? extra GPU?What operating system are you running? windows 7/8? are you running some sort of GUI over the top? how have you set up, for instance, just listening to normal radio?

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: January 22, 2014, 12:19:30 am
content: Quote from: ptodorov on January 21, 2014, 09:23:02 amI was asking if you could display data on that lcd from you carputer (but my wording sucked).That's the spirit!! The car companies are always trying to hide stuff. They're probably infringing on someone's patent and want to avoid legal troubles. Maybe if you uncover some patent infringement you can have them pay you not to squeal. Wait that might be blackmail.QuoteThis is a great idea. Could save a tire or wheel alignment or worse.QuoteAnother potential money saver.QuoteI think pitot tubes might work. Maybe two would be needed, not sure. Might be complicated but you could find true wind direction and speed and use that with fuel consumption just for fun!QuoteWell cameras can be really small and I think the best way is to have an external mirror and an internal camera. Focus the camera on the mirror and rotate the mirror as needed. Might need to do some post-processing for un-mirroring, rotation, parallax, etc.QuoteInteresting, there's got to be some passive solution, some kind of doppler thing??Okay I looked, might be a starting point, it says 200m on this pagehttp://www.faqs.org/patents/imgfull/20130234880_01

author: ptodorov
author_rank: Contributor
timestamp: January 23, 2014, 09:23:32 am
content: Quote from: GiskardReventlov on January 22, 2014, 12:19:30 amThis looks promising. I'll have to do some learning in order to implement itit may be fun. The other thing I was thinking about is usingtwo cameras and there are some open source robot vision algorithms that can do distance. On the Volvos they use one camera and search for the expansion of the object in sight for example when approaching a car they calculate how fast it fills the field of view of the camera. Several years ago they performed a test at the local car fair where they drove a Volvo at a wall and since the wall already filled the field of view of the camera they just smashed the car in the wall (it was supposed to auto brake).Quote from: bbjk7 on January 21, 2014, 11:35:55 pmYea the obd protocol has multiple standards and it seems Toyota's one is not very common. BMW's for example have a Bosh board computer that you can re-flash using the OBD port without having to desolder chips or use the factory port and do all kinds of wonderful and awful things.For the carputer I've used a Micputer ITX-M25E21A mini ITX motherboard with an on-board fanless Intel Atom 1.86Ghz low consumption dual core processor. I've put a 4GB DDR3 1333MHz RAM and a 64GB M-SATA solid state hard drive (high vibration mechanical disk drives cost a LOT). I'm running a custom build linux and for the GUI I'm firing a fullscreen Chrome at startup. I know it's far from great using HTML5 and javascript for this application and I really wanted to do the GUI withQtbut I didn't have the time to spare. In the browser I've developed the interface pretty fast and a lot of the code is pretty widely available like music players, video players, maps, calculators .. etc. The setup I currently have doesn't include radio, I may put aUSB TV tunerfor version 2, but I'm not 100% sure since I usually don't watch TV or listen to radio at all.Quote from: calexanian on January 21, 2014, 04:01:32 pmWow I envy youI wish I could meet some of them one day. As for Paramount I really don't understand them, there is this huge fan base thirsty for more Star Trek and and they just sit there and refuse to make some more money.. it really is a mystery for me. I've read somewhere that it will come back to the small screen, but it was a vague report of someone having heard something.

author: bbjk7
author_rank: Contributor
timestamp: January 23, 2014, 02:32:02 pm
content: Quote from: ptodorov on January 23, 2014, 09:23:32 amWhoa, knew BMWs had all the bells & whistles but reflashing through the OBD? Now that really is 'gilding the lily'. Still wouldn't swap it for my zippy sportivo thoughQuote from: ptodorov on January 23, 2014, 09:23:32 amNice, very interesting... Now excuse me while I find the horrible advert audio coming from somewhere in the 9 tabs you made me open...WHAT? a car without a radio? is that even roadworthy?Didn't think as far as the hard drive being solid state but now that you've mentioned it, that's a no-brainer. Unless you could run it on SD-cards like a raspberri Pi or something.Also forgot that power consumption is an important consideration to be included...Quote from: ptodorov on January 16, 2014, 05:12:03 pmSoooo (250mA-120mA)x12V = 1.56W when in "sleep mode" or completely turned off or..? How does thishttp://www.tomshardware.com/reviews/mini-itx-gaming-radeon-hd-7750,3369-9.htmlcompare? Also, doesn't 250mA of current draw mean that a typical 60Ah battery will still last about a week?Honestly can't say I've had much experience with coding, custom OSs and all that jazz. My trade is electronics, and I'm only an apprentice at that.Love learning about these things though and I'm quite eager to take on this project myself. The only daunting thing is the interface.. Which is probably the most important thing in a car... Can just imagine myself running something like windows xp, swinging around a mouse on the dash trying to find the tiny "start" button in the corner just to open media player for some music. All this while trying to avoid trafficWhy is it "far from great using HTML5 and javascript for this application"? What are the limitations?I'm trying to work on a starting point for the interface.. Start experimenting in linux with that fancy Qt-project thing you mentioned? is that C++?

author: calexanian
author_rank: Super Contributor
timestamp: January 23, 2014, 03:19:19 pm
content: Paramount wants to re do trek in a darker image. They want to make it like every other show. More sex and violence and no morals or hopeful view of the future.

author: ptodorov
author_rank: Contributor
timestamp: January 23, 2014, 03:38:48 pm
content: Quote from: bbjk7Well I measured 250mA at the car battery with the arduino inside in "sleep mode", that is sleep mode on the ATmega328 with the actual computer turned off. When I disconnected it I've measured 120mA. Now I'm sure the ATmega doesn't draw that much but this is what I've got. Maybe the linear voltage regulator was dissipating the exes as heat. As for the battery capacity that was exactly what I tough also, but the combination of chilly weather and short runs to work and back drained it gradually.Quote from: bbjk7In my opinion a web based solution isn't great because it's too much overhead. Running a browser witch is parsing html and interpreting js is just an overkill and waste of resource. Also the http communication becomes a bottleneck when you want fast updates on the screen, even with a local running web server.If you want to spare yourself from the coding you could check out some ready made solutions. You can find themhere. Basically there are several different frontends that are either the whole OS or just a program that autostarts with the OS and then there are apps that you install on your frontend. I don't have experience with any of these and can't give you an advice witch is better. But they have some really cool apps like WebRadio, Trip Computer, GPSTracking, TrafficCams, FuelPrices etc. There is even a street name announcer app(can't imagine how annoying this is going to be)

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: January 23, 2014, 09:08:26 pm
content: Quote from: ptodorov on January 23, 2014, 09:23:32 amCameras probably least expensive way to go. Love the volvo story. Ha! What's that german word for it.... schaedenfreud or something....Like the Tacoma Narrows bridge....if ( (fieldofviewfill == lastcheck) && (speed > 0))stop(now);Oh as if we haven't given you enough ideas yet.... how about an inertial navigation system for those times when GPS isn't working.Also maybe display the KBB value as a function of mileage and age, couple that with an accelerometer and whenever the car experiences massive G's (accident) adjust the value. "It's time to sell the car now <YOUR NAME HERE>, I told you that yesterday was optimum sale time based on ebay prices." (maybe too naggy)Also keep track of tire wear, oil change reminders, timing belts (for OHC). Make sure you use GLaDOS's voice.

author: SArepairman
author_rank: Frequent Contributor
timestamp: January 24, 2014, 12:23:32 am
content: Quote from: calexanian on January 23, 2014, 03:19:19 pmeven darker then the current ones?or are you saying the two new ones are dark?

author: calexanian
author_rank: Super Contributor
timestamp: January 24, 2014, 04:18:58 am
content: Most television companies want edge, grit, and sex. not good story telling. Star Trek was always about the story.

author: kudzo
author_rank: Newbie
timestamp: January 24, 2014, 12:07:17 pm
content: I am currently toying with the idea of putting an Android Tablet like this one herehttp://www.efox-shop.com/tablet-pc-freelander-1024-600-android42-7-zoll-dual-core-12ghz-mtk8312-bluetooth-g-291403any suggestions on feasability

author: ptodorov
author_rank: Contributor
timestamp: January 27, 2014, 02:15:56 pm
content: Quote from: kudzo on January 24, 2014, 12:07:17 pmCheck out this video

author: Stonent
author_rank: Super Contributor
timestamp: January 27, 2014, 05:17:56 pm
content: Quote from: calexanian on January 24, 2014, 04:18:58 am

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: January 28, 2014, 03:22:24 am
content: Quote from: ptodorov on January 27, 2014, 02:15:56 pmDid they get really lucky, that iPad fit perfectly in that space. How did they get the speed to display? Was that just GPS or did they connect to the car?I heard him mention the ECN but he didn't give much detail. I also wonder about glare on the iPad and driver distraction. But a nice project.

author: calexanian
author_rank: Super Contributor
timestamp: January 28, 2014, 05:05:32 am
content: Quote from: Stonent on January 27, 2014, 05:17:56 pmAwesome

author: kudzo
author_rank: Newbie
timestamp: February 07, 2014, 11:41:04 am
content: that's exactly what I am planning to do, just using a cheaper tablet..the hardest part for me is actually finding a double din console for my car..oh btw I have also the controlls on the steering, so my idea is to use those for the volume (either configure an arduino as usb kbd or something similar).