Poor Man's Data Logging

AliK

Vehicle Dating Officer
Staff member
Club Member
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.
 

jonbills

Membership Secretary
Staff member
Site Administrator
you could get a speeduino for about £120 and just log those sensors, no need to have it control anything.
 

Russell

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.
 

AliK

Vehicle Dating Officer
Staff member
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.


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.
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
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.
I bet you wear a Fitbit when making love!
 
Last edited:

Russell

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....
 

AliK

Vehicle Dating Officer
Staff member
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....

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. :(
 

Russell

Club Member
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. :(

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

AliK

Vehicle Dating Officer
Staff member
Club Member
Does it provide any form of tach output? Otherwise just make some simple circuitry to pick up the standard Tach signal.

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:

MCBladeRun

Club Member
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!
Would Pulse width Modulation work around the spikes?
 

Russell

Club Member
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!

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!
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
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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