Poor Man's Data Logging | The Z Club of Great Britain
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Poor Man's Data Logging

Discussion in 'General discussion' started by AliK, Aug 3, 2021.

  1. AliK

    AliK
    Z Club Member
    Staff Member Moderator

    I like data! I need data! I LOVE data! I live and dream data. I feel empty, without purpose and am feeling hungry!

    In all seriousness, I want to log as a minimum:
    • AFR
    • MAP
    • RPM
    So a 4 channel analogue jobbie would be ideal. But I don't want to spend the £400+ on the well known brands.

    I want to hook up my AEM AFR gauge with it's 5v output, use MAP and RPM sensors that do pretty much the same but yet TBD.

    Is anyone using anything that costs around the £100-200 mark?

    Google tells me about Loguino but I don't want to do a lot of coding to get it working. Then there are some other more techie ones that need some work. But I want a pretty much plug and record + download to .CSV file. I don't care about real-time analysis or fancy software - I eat Excel for breakfast and lunch and prefer raw data. In case you are wondering I have PPT for supper and snacks (frankly built a career on PPT).

    I have in the past used my iPhone strapped to the passenger seat pointing at the iPad running the 123 Ignition app and my AFR gauge - very poor man's data logger.

    So, any thoughts? What are people using? Any cheap options?

    Let me pre-empt some responses (joke flag flying high, please don't take offence):

    @Rob Gaskin - What do you want that for? You need to drive your car more and tinker less.

    @jonbills - Just get a speeduino and EFi and stop dicking about with the obsolete technology of carbs.

    @franky - Just buy some DCOEs or a Kameari <insert any product here>

    @status - The only data you need are your tyre pressures and level of beer in your pint glass.

    @Albrecht - Naoto-san in Fujisawa had an elegant solution now lost among the weeds of time.

    @Woody928 - Not having kids I'd just buy the most expensive option possible.

    @johnymd - I have data loggers on all 17 of my S30s.
     
    toopy, johnymd, SacCyclone and 2 others like this.
  2. jonbills

    jonbills
    ZClub Administrator
    Moderator

    you could get a speeduino for about £120 and just log those sensors, no need to have it control anything.
     
    Paul_S and AliK like this.
  3. AliK

    AliK
    Z Club Member
    Staff Member Moderator

    I bloody knew it!!! :EXTRAlol::smash:

    Good advice - TY!
     
    jonbills likes this.
  4. Russell

    Russell
    Z Club Member

    Or.... spend 99p on an arduino nano, a couple of £ on a pressure sensor and some resistors.

    Bit of coding and you are done. EASY!
     
    Paul_S and AliK like this.
  5. Russell

    Russell
    Z Club Member

    Just have the code outputting the serial data and time stamps either via serial that can be collected on a laptop, saved to an SD card or even transmitted over bluetooth.

    Could then have an excel macro to pull it into graphs and all sorts.

    OHH also you could add temperature - Ambient and intake, some kind of altitude via barometric pressure or GPS data. Then you could have the whole lot plotted on graphs.

    Possibilities are endless.

    Could even have some kind of min/max thresholds which set off some form of alarm or light.
     
    datsfun and AliK like this.
  6. AliK

    AliK
    Z Club Member
    Staff Member Moderator


    You see - this is exactly what I'm thinking - we need to talk! The Excel end I am more than capable of sorting but the sensors / hardware side is the bit I need to educate myself on.
     
  7. Rob Gaskin

    Rob Gaskin Treasurer Staff Member Moderator

    I bet you wear a Fitbit when making love!
     
    Last edited: Aug 3, 2021
    Kest likes this.
  8. AliK

    AliK
    Z Club Member
    Staff Member Moderator

    I'm married with two young kids ... there is no longer a need for that data!
     
    Robbie J, tyroguru and datsfun like this.
  9. Russell

    Russell
    Z Club Member

    I still need to dust off my arduino speedo and finish that off, then start my tacho for my project yet!

    Here is what I would buy though -
    Arduino Nano - Tons on ebay
    Pressure sensor - https://www.ebay.co.uk/itm/363330534926?epid=9012059024&hash=item54982ffe0e:g:MrwAAOSwys9gWIK9
    Does the 123 ignition give out a digital tach signal at all? If so, no parts to buy there
    Real time clock for time stamp - https://www.ebay.co.uk/itm/152508668079
    SD module to store the logs in - https://www.ebay.co.uk/itm/322502815052
    Waterproof temperature sensor, could have it dipped in your coolant - https://www.ebay.co.uk/itm/322461235769
    Air temp and humidity - https://www.ebay.co.uk/itm/353601481994
    Barometric pressure to calculate altitude - https://www.ebay.co.uk/itm/283518687928

    Not sure what more info you could ever possibly want than that.

    Write the code to take a reading from everything with a time stamp every X amount of time and write it to the card. Whenever you want, pull the sd card out and stick it in excel.

    THEN - Run a Machine Learning model over the data to learn the exact fuel mixture required in every possible scenario.

    THEN - Have the logger output live to the ML model which then outputs the correct mixture, that connects to the adjustment screws on the carbs with small stepper motors and constantly tunes your car on the fly.

    Finally, we make it a marketable product and make millions....
     
    johnymd, franky and datsfun like this.
  10. franky

    franky Well-Known Forum User


    have you seen this sex/data GOD!? He doesn’t make love, he makes whole numbers
     
    AliK likes this.
  11. AliK

    AliK
    Z Club Member
    Staff Member Moderator

    Very likie!! Thank you. I will study this in detail and get back to you with questions.

    That is a beef I have with 123. It really wouldn’t take a lot to allow the app to record all its data onto a phone or to provide a TTL level output for the tachometer. I would gladly pay a little extra for those things but they just won’t do it - I have had quite an email exchange in those topics. :(
     
  12. Russell

    Russell
    Z Club Member

    Does it provide any form of tach output? Otherwise just make some simple circuitry to pick up the standard Tach signal.
     
  13. AliK

    AliK
    Z Club Member
    Staff Member Moderator

    Annoyingly, it doesn’t it just integrates with the car’s wiring. The Spydia thing I was trying earlier takes the negative from the coil and uses a frequency to voltage converter IC. But on a flamethrower coil the negative can spike to 100v and bounce about!! So if I use the same method, it needs to be an opto-coupled high voltage FET of sorts (and some code to “de-bounce” it).

    The Spidya didn’t work properly and I ran out of time and enthusiasm to play with it. I may fix the original circuit and take an op-amp / fet based signal from it to avoid taking current away from the analogue circuit.

    The other alternative I’ve been thinking of is an optical pickup on the crank damper. Or even on the blades of the alternator but the latter becomes less accurate and varies with the belt tension and wear.

    All food for thought!
     
    Last edited: Aug 8, 2021
  14. MCBladeRun

    MCBladeRun
    Z Club Member

    Would Pulse width Modulation work around the spikes?
     
    AliK likes this.
  15. AliK

    AliK
    Z Club Member
    Staff Member Moderator

    Interesting idea, tell me more.

    Here’s what is happening at the coil ...
    F53850A1-6CA1-4873-A95A-A02AD004168A.jpeg
    Are you suggesting a pwm with a very high input trigger level?
     
    MCBladeRun likes this.
  16. Bazzateer

    Bazzateer
    Z Club Member

    :conf2: It's almost as if you guys are trying to communicate on some level! :conf2:
     
    AliK likes this.
  17. AliK

    AliK
    Z Club Member
    Staff Member Moderator

    Just thinking again about this suggestion, are you nudging me towards a Schmitt Trigger?


    too funny LOL
     
  18. MCBladeRun

    MCBladeRun
    Z Club Member

    :confused:
    :confused:

    Honestly don't know what those are Alik - I'm not an electronics man, I just know from past experiences in my line of work that a pwm can get around these problems
     
  19. Russell

    Russell
    Z Club Member

    This is a way simpler problem and you just need to stick an opto isolator, a couple of diodes and resisters on the tach signal. It will pick up the pulses from the coil that would release the magic smoke from an arduino and output a nice safe 5V/3.3V pulse to the arduino. Then its just a bit of code to turn the pulses into a digital rpm output for your excel sheet.
    Probably about £1 in parts!

    I dont know tons about it but an opto isolator is a Schmitt Trigger. You wont need to mess about with anything massively complicated to iron out the spikes other than the conditioning achieved with the resistors.

    Never tried it though so if you invest in all the parts to test it and it doesn't work I'm afraid you have lost an entire pound note!
     
    AliK likes this.
  20. Rob Gaskin

    Rob Gaskin Treasurer Staff Member Moderator

    Pound Note? I can remember the Ten Shilling (50p) Note.

    It's amazing how much knowledge some people have with electronics and what you can get for your money.

    I thought this once when buying a rubber hose for my Audi - could have got a couple of electronic watches for the same price!
     

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