924Board.org

[musicalannette]

Hi, im not really "up to speed" on the modern racing scene, but do have a boat, never wanted a computer on-board as the costs can be ridiculous and when you rely on them the moving parts of the disc drive (although sometimes amazingly robust) can suffer from physical shock damage and leave you up sh*t creak without a computer.

However, i'm sure some of you must have seen a Raspberry Pi and whilst i was looking at it as a handy on board pc with reasonably low power consumption (always worrying about power consumption with only batteries), i came across this.

http://www.pistonheads.com/gassing/topic.asp?t=1216528

Weighs hardly anything, is fairly small, quite rugged, very cheap and quite low power consumption. There are other boards out there similar to the PI, but i doubt any will have its exposure OR its level of interest. Its certainly the best way to turn your tv into a smart tv.

I am sure there must be other people out there thinking on a similar thread.

in 5 years im sure nearly every club racer with monitoring gear could probably be using one....would it be worth starting a raspberry pi racing forum?

i surely wish there was sailing one forum, that is for sure.

You would have to build an interface board as the basic board is pretty unprotected and it might get expensive if things go wrong and you start using the things a fuses. If you fitted a bigger SSD drive or when it could probably do on board video too.

It would mean with gps you can have super accurate time/position data without a load of timing gear on a practice day AND be able to record and monitor your modifications/running vehicle sensors/data AND Video your hard work so you can watch your performance AND Video the car when your not there in the paddock so you can see your fellow competitors nobbling the car when your not there!!

This is a nearly a perfect computer. ASIC down to one chip and nothing else on the board. Dont think it is something they pulled from a mobile phone either.

I have no idea about forums and the like but i am sure if you made it a general data logger with video and gps pi forum there would be a ton of interest.

At the very least, it could run a zx spectrum emmulator and you play porsche 924 in the paddock.......
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I KNEW white wall tyres were invented by Americans .....just not at Boeing.... to be fitted on the 737.....

[924RACR]

Neat...

A few key bits regarding data... #1 thing that's as important as gathering the data is being able to process it and analyze the data in a very useful way. Obviously with the commercial packages already available, that software work's been done, but it would be (I imagine) a significant effort required with this solution.

The other pain with taking data on a 924 is the complete lack of electronics, so no OBD etc to tap into for channels as shown on the bike. Actually, very annoying is that my other racecar, a prototype with a bike motor, also doesn't have OBD2 diagnostics despite being a 2008 motor with EFI and an ECU! So taking data with that is harder than it needs to be.

Anyway, this means you would likely want to add some sort of presumably USB-based hub with an A-to-D converter to pull in analogs from sensors to allow logging of that data - eg, oil pressure, eng temp, etc.

Have you looked into Harry's Laptimer? I seem to recall that it's now a pretty complex little data logger with GPS basis that'll run happily on a smartphone...

Of course, the possible big advantage with this (the Raspberry Pi) would be the video integration, if you could make that work well to be pretty streamlined...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[musicalannette]

no, i had never seen harrys lap timer, it looks like a good simple stand alone solution.

you are right about software, the basic logging isnt too bad, but making it easy and quick to understand (graphical interface or in my case finding public domain hydrographic data for the uk) could be a stumbling block, thats why i suggested starting a forum. there may well be many students only too happy to have a project to get there teeth into. it will probably be a pi they do it on as they are aimed at schools.

i dont know of many lads that dont like engines. cars etc.

i was looking at at getting serial data (similar to obd2 but for marine instruments from wind/depth/gps to allow you to know where you are plus have the ability to store books in a limited space) called nmea data.

what the pi has, is the capacity to sense or control something more than just serial data.
it is what it was intended for.

i was actually thinking of monitoring your analogue voltages, say from an oil pressure sensor, reset pulses for the fuel pump or pulses to a tacho for engine rpm the gps data can give you speed, but a steering position monitor and throttle position monitor or a sensor off a jag xf for wheel position isnt out of the question, the pi has the a/d converter all in there to get that info and turn it into a number, allowing the the software guys to do their work

it would be basically carrying out the function that the vehicle management computer does but probably be more expandable, it could also be a much much better data logger with video output to boot.

adapting to something that ISNT serial is what this WOULD be brilliant at, the sensors wouldnt cost too much, mounting the suspension movement sensors to the car would be the tricky bit. But some of the cars sensors are there already to be tapped into. most are pretty generic and operate between 0 volts band 14 ish volts. a g sensor would be very easy.

if you wanted, it has the capacity to output signals. so if you fitted a electrically actuated linkage to the throttle for the pi to move you could have full fly by wire throttle control, giving you traction control or cut ignition timing for a rev limiter. but that would be of more interest to someone who wants to perhaps modify there car to the point they have to add something like that. but once you have the number, the pi can turn it into a voltage.

I mean, it could probably display all this on a lcd screen while you sit there driving as well!
which is what i wanted the pi to do with the boat charts. So it could be you instrument cluster.

its just thought, if you did start a racing pi board, you would probably attract quite a bit of interest along with quite a few computer teachers or lectures. They have done there degrees, struggle to find something interesting to grab the kids attention and are probably bored teaching kids same old stuff and have a bit of time on there hands during the day.....so there might be more help at hand than you ever ever dreamed of.

i think it would be a brilliant board to set up, the pi has been out about a year or two, has taken off, has tons of interest, and is pretty compact and has high connectivity with low power consumption and weight and is robust. to design a chip like that would run in to the millions, i doubt there are many racing data loggers/displays out there that are cheapish with better core hardware.

start with gps, time , speed oil pressure, revs and video output to a lcd display i think a vehicle serial data reader is probably abit like giving Einstein your cheques to balance.

once you had that adding something like throttle position would be easy. it could just grow and grow,

remember, it is a fully fledged computer capable of running linux, so all the graph display side is there already.

the more i think about it, the more i think it would take off, especially with the club motorsport/hillclimb and trackday special or modifying scene.

i dont anything about running a forum, but a motor racing pi or vehicle data pi forum, would i am sure ,really take off and probably, ultimately create something very, very usefull and in my opinion, be in keeping with the best spirit of the web.

i would be willing to help out with hardware interfacing, where and when i can.
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I KNEW white wall tyres were invented by Americans .....just not at Boeing.... to be fitted on the 737.....

[Mars478]

Cheap Solid State drives can solve the problem of a spinning HDD.
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924, 82, 5 speed, dark red, 500 dollar special.

Daily: 99 ML320, 210k and still trucking.

[musicalannette]

Yes, now they are becoming very reasonable indeed, and for large data logging stiuations would be used, most places i have seen have either had real time hard copy plotters UV in some high speed cases or stored to mag tape, but then they allready had the gear and certainly wouldnt go out a pay for something while it all works.

i suppost you could usb connect the ssd drive to a pi. and shuffle data over to it for larger files (like video). certainly as main archive. imean the pi will keep all your books on board!

as for using a ssd with a full blown pc.... well its a bit power hungry and i think the pi will happily run off 5 volts so you can make either a regulated supply from the car or run it off its own small battery, but as its 5volts it will be happy on a 6volt car system system too. infact due to weight, that would probably be the preferred method. you could probably wifi to a modern big srceen, which might be really neat for studying data on.

i would probably start by writing a list of what you would want to monitor and how often (in thousanths of a second say). is it analouge or digital?

example: the pi can measure a moving voltage for your oil pressure - analouge

it could also measure when your brake lights come on (crude breaking measurement) so this is either on/off - digital

what is really cool, the pi could have set limits for things like oil temp or pressure (which it would be monitoring) and it if the limit was outside a parameter it could give you a warning light or buzzer say.

The most cost effective way of setting a display up for a 12 volt system is to buy a stand alone lcd panel from china say 7inch, this could give you ample room for instruments to be displayed, but this abit of a project in itself. you could buy a panel for $30 or $40 and would be worth while later on.

but this where the pi comes into its own.

to get you up and running, for you could use the on-board hdmi or composite out to connect to a 12v in car entertainment screen. very cheap,very quick and its 12v. you could probably strip it out the case and make your own lighter version for fit where you needed it.

Anyway

I think I would prbably start with;

gps sensor. (would give position, very very accurate time, and thus calculated speed over ground).
brake light switch sensor.
oil pressure.
oil temp.
water temp.
alternator voltage
rpm

and with these you have a means to set limits of "normal operating range" for warning lights. the pi has the design there to give you the outputs for the warning lights and even(if you measure rpm) an rpm dependant set of shift lights or an ignition cut rev limiter say..

a throttle position sensor would also be nice.

im not sure about g sensors, i would probably want to measure suspension travel and body roll before starting down that path, and have seperate transverse axis sensors front and rear.

but i mean, once this is there in a program, you might only want to use it for shift lights or as a water temp monitor. and the rest can sit there unused. the only thing it might do is slow how often the data can be captured down abit, but i doubt it will be that noticeable anyone would complain.

As i say, i think there are a lot of guys out there with skill, time (the odd hour to kill and a pc), and maybee a bike or a car or a friend on that position. If you could put them all together in a melting pot something truly gold might come out when you solder with a bit of lead(or tin).

Its sort of 924 related, especially if you track day or race, which i think a fair few 924 drivers do, as i say, i dont know too much about running a forum, and i think the most difficult part would be fitting things like suspension movement sensors or throttle sensors, you could even monitor things like vacume/airflow orput a lambda sensor in the exhaust and give yourselves some extra information. you would be able to use your track time to know more not leaving you guessing as much or the data might save you a small fortune should something be on its way out and decide to take something with it an expensive way.

the actual sensor fitting might take a bit machinig and head scratching more than outright cost of the sensors.

I am sure most people have a datalogger or a shift light, rev limiter, smart intrument panel even a video monitor.

There probably seperate, they probably cost a fortune, and chances are most people only have SOME of the above due to cost but WOULD like all of the above to be available.

Either I am over estimating what a PI can do and have toomuch enthusiasm or no-one else is either interested or believes anything could come to fruition. I am just thinking of a friend who used to sprint and hillclimb, probably would never buy a data logger if it ment a new pair of tyres were going to be compromised, was competitive but also enjoyed the club scene and as a winter project, it would be neather too costly, taking money from the essentials (like new tyres) or if it was long term time consuming (you could work on the software for a few hours if you had a pc and were away from home in the evenings for example).

When it comes to open source, just look at Linux Mint.

This board beggs to be used insituations like i just described. I dont know much about autoshop training in the states, but i am sure this could be a worthwhile and i think there would probably be enough programmers who would eventually show an intrest to get it up and running.

Perhaps this isnt the best place to throw the idea in the ring, the people running this forum are extreamly busy, and are into the 924, i think the 924 is a pretty organised racing scene personally and has been for many years as i can recall.

It is all words, enthusuiasm and bright ideas at the moment,but hopefully there might be a little vision in there.

If you can have all that monitored and displayed for about $200 $300 of hardware/camera/sceen/PI do you think you could get it enough people on board to get it working? would there be much intrest?

Anyway, best to find out.

Leave a response
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I KNEW white wall tyres were invented by Americans .....just not at Boeing.... to be fitted on the 737.....

[musicalannette]

Found this on the site.

http://www.raspberrypi.org/archives/4462

Seems someone else thought the same way about using the onboard diag plug.

Sensor refresh rate is Nooo use for data analysis maybee apart from a temp monitor, but reading the article I think the PI only asks the cars cpu for data every 500mS. So i think that would not be a limiting factor and the data could be very useable.

Certainly shows it can handle video grabbing/data storage and sensor data overlay at the same time. so i think running a display (intrument panel) or shiftlights on top would be no problem.

Its the PI's onboard a to d and d to a convertors that would come in usefull for none obd2 equipped cars (924's and pre 1995ish cars, modified's and out and out racing cars). It could just monitor the voltages to get the data (and for pulses, say from a abs or wheel sensor) voltage and time,which could give you frequency.

Perhaps it is my background, but reading up, i think it would be easier to use the PI to monitor the analouge voltages than to try and interface with the OBD2 if your not too up to hexidecimal data strings that appears to churn out. Whats really great is the PI having the AtoD convertor, it can grab data from sensors that are EXTRA to the ones allready fitted to your ODB2 equipped car (such as suspension travel).

Anyway, as was thinking of using it for a small boating pc, with chart software and book storage,maybee with internet access if there is wifi about. What i was doing is going a bit off track.

As there is not much of a response, i wrote this to try and either show you it IS very do-able and there are lots individuals who if they pooled resources, kept it open source, could probably save some very clever guys duplicating each others efforts. As its 5 volts supply i guess leaving the pool of interest that comes from the bike scene out would be stupid.

If you were lucky you might end up with a generic vehicle data/video logger (obd2 and analouge) with optional instrument display, shift lights and warning lights. What bits you did't fit or use would be upto you.

If it was generic software/ the hardware for the analouge sensors would generally be very similar, you could even end up with the generic printed circuit boards and leads made up for less technically minded or trained to turn it into a reality or people and places to go worldwide who know what sensors to fit and how to fit them, across all types of vehicles. The first time i saw the wheel movement sensor on a JAG XF, i thought, what can i use that for!!! I see all that side of making interface boards to monitor the sensors as very do-able and would be happy to help where and when i can.

It could probably all end up a bit too professional! Especially if you can get the interface to be user friendly. If you think about having it all mounted along with an LCD screen in a case. I mean, it could be used as a computer, video camera display, instrument panel, somewhere to analyse you graphs without the need to buy or take along anything else to say the nurbergring!! HOW GOOD WOULD THAT BE!!
Have a 2 or 3 inch screen if you have a bike say!

But if there were bulk buying an all singing or dancing one could probably be built for around $200/300 of bits, including the screen and sensors. It dont know how many evening meals out that buys, but it is where all of my savings would end up going! Thus reducing ear ache into the bargain!!

What it needs is a forum so all the motorsport guys can get together and not duplicate each others work, and a name when you look on google it's something easy to find so people who know software (probably do it as a day job), can offer a bit of simple advice to complete idiots. Or,as happens quite commonly, if they feel a bit constricted with what they can't do at work, can have a bit of fun or show off on.

I probably going on like a DICK HEAD. But wouldn't you be getting more fun for your money? If after paying for your day out you can sit at home and analyse what you have done? Even share data with a mate in the pits so you can both improve over the competion or work out which way to go with settings quicker!

OR IS THIS PI IN THE SKY? I honestly thought as they went for raspberry pi and addafruit, the name lemon motorsport logger was a good one.

It would be funny to go out of your way to set out and build a LEMON. Especially if you can imagine it to be as good as it cold be.

If anyone knows about setting up forums and whats involved if they could also leave a response, maybee i could stop guessing weather people would be intrested or possibly wasting my time.

Anyway, thats me kicking the ball off, lets see who else has an input, or indeed if it actually goes anywhere.
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I KNEW white wall tyres were invented by Americans .....just not at Boeing.... to be fitted on the 737.....

[musicalannette]

Vaughn,

Reading your post again,sorry i missed your question.

I think, remembering what i read up on about the PI, there is an i/o (input/output) port in the middle of the board, you can confingure the pi to make the pins used for sending a signal or recieving a signal.

This is done in software, i have not looked it up, this is off memory, so dont quote me on this. but usually with most designs there are pins or connectors to a chip or socket that are only for output, some only for input and a very few you can choose to change, but if i remeber the pi you can choose most if not all what you want (very unusual) which would make sense as an educational swiss army knife computer. i think the a to d convertor is bulit in aswell. if it isnt, this is no great shakes, you just make a simple board up with a couple of chips to turn a voltage in to a load of 0's and 1's the Pi can turn into a number.

you could sense analouge signals through the usb aswell. or send shift light or warning light signals down there, but the sensing of analouge signals would make the most sense down that main i/o port in the middle of the card. as i said, i am pretty sure there is on board analouge to digital converstion for the computer to turn a voltage into a number.

if you want more sensors than the PI has inputs (say if it got to the point there were 20 analouge sensors), you have to what is called "tdm" the input.

time division multiplexing(tdm) is best explayed to someone who is non technical as a crying baby. i have one baby it, crys. if you have a nanny,who spends some time giving it attension, it stops.

but if there are two babies, by 1 nanny spending a bit of time with each baby in turn, they both stop.

this is crudely tdm. 1 a to d convertor (nanny) being swithched after a period of "sample" time between inputs (bablies) reading them over and over round and round.
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I KNEW white wall tyres were invented by Americans .....just not at Boeing.... to be fitted on the 737.....

[musicalannette]

turns out reading up a bit more,there isnt an internal convertor. there are 17 configurable ports input or output it is up to you, with a few more, unused that the designers might unclude in later versions.

in this case, you could use each selected digital input with a slightly different but very similar system to measure voltage.

http://www.raspberrypi-spy.co.uk/2012/08/reading-analogue-sensors-with-one-gpio-pin/

or use 8 or 12 (commonly manufactured chips) of the ports to sample to 8bit or 12bit resolution of the voltage (i.e. down to 1/256th or 1/4096h) of the max voltage you want to measure.

these 8 or 12 ports would be tdm to give you multiple inputs.

so for 15volts car system, the smallest measurement change would be 0.058 of a volt for 8 bit, or 0.004 volts for 12bit. , for a 7 1/2 volt bike system it would be half that.

personally, out of the 17 pins, i would use 12bits input data time diviseion multiplexed (nanny/baby) to give probably high-ish end logger performance. have 2 pins to give me a 4 stage shift light (after digital conversion), 1 pin oil pressure warning, 1 pin water temp warning and have a system where i can turn both lights on should i need to for some other warning i can think of!!, and 1 pin input for start/stop reference (if you have a off car timing light control you could use it as a trigger) from a cockpit button if you have the time to press it while practicing.

This could give you start/stop lap info, start a new lap log file, which if linked to distance counter fitted to say a wheelspeed, electric speedo or abs sensor of the car might make the track become visable to the gps/g force, braking, throttle data suspension data it is aquireing,

trust, me if you dont know the bumpor the corner your looking at you the data will be next to useless, and i dont think gps data will help unless there is someone with mapping experience on board.

if it data was all tied into video i think it might be down to video refresh rates when the logger updated. this way the computer can get on with the job of logging and not have to wait around the the video board to be captured (caparably it will be waiting ages i think, and really compromise the logger).
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I KNEW white wall tyres were invented by Americans .....just not at Boeing.... to be fitted on the 737.....

[musicalannette]

in the case of the 924 it would mean reading a voltage (say from the water temp sender or tapped of the back of the guage) connecting it a homemade board (or possibly a bought one if they arent too dear) which can convert the 0 to 15 volts into 12 0's or 1's, say for something like the brake light the reading (which is digital) you could still use the anolouge input to get a graph of the data.

it would be looking for existing software to graph the data and/or how to save the data in a format so it can be graphed several pieces of data side by side that might save masses of work.

remeber this is computer and i can just about guarentee thisisnt the first graphed data fromaPi out there.
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I KNEW white wall tyres were invented by Americans .....just not at Boeing.... to be fitted on the 737.....

[musicalannette]

apparently you can connect up to 4 of these up an select any one of the 4 a to d's on each board so you can have 16 before you have to think about more inputs.

probably some1 will want more, but its not too bad a start.


https://www.modmypi.com/adafruit-4-channel-i2c-12-bit-adc

sample rate is up to 3000 per second which only leaves a problem for engine rpm monitoring as the spark pulses will be getting close to that value.

what am i talking about its revs per minute........
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I KNEW white wall tyres were invented by Americans .....just not at Boeing.... to be fitted on the 737.....