Cheap easy data logger for vehicle?

[Donk]

Could you fit a longer throw shifter to reduce the chances of money shifts?

https://howtomechatronics.com/tutorials/arduino/arduino-sd-card-data-logging-excel-tutorial/
Should be relatively simple to replace the temp logger with something that reads the RPM instead.

 

[87manche]

These cars are turned on and off many times while they are during a rent, so that type of system would not work at all.

The car has a factory tach and has an easy to tap signal wire under the hood.

"this could probably be done with an arduino if you really want bulletproof data logging.
Have to figure out how to get the tach input into the arduino. I'm assuming it has an actual factory tach, so that output should just be pulses at a TTL level.
the rest of it isn't so hard. Just have it log the RPM every second to a text file on an SD card."

^^^ this part, not so easy for me, would be pretty much impossible for me to do that.

step one would be to put an o scope on the tach wire and figure out exactly what it is, but I'd imagine it's just a frequency that changes.
You'd have to determine it's voltage.
then probably a basic power divider setup to make it safe for an arduino input.
then just count the frequency and divide it into RPM.


but what engine and ECU are we dealing with here?
I'm sure there's a data connector somewhere, and it probably outputs RPM data.

 

[crispins]

step one would be to put an o scope on the tach wire and figure out exactly what it is, but I'd imagine it's just a frequency that changes.
You'd have to determine it's voltage.
then probably a basic power divider setup to make it safe for an arduino input.
then just count the frequency and divide it into RPM.


but what engine and ECU are we dealing with here?
I'm sure there's a data connector somewhere, and it probably outputs RPM data.

1990 Mazda Miata

it has a data connection under the hood and one of the terminals is RPM

 

[Donk]

1990 Mazda Miata

it has a data connection under the hood and one of the terminals is RPM

I've just had a quick hunt and it seems the the ECU has sweet FA to do with the tach, tach is fed by the ignitor.
that IG pin should give you a 12v square wave but may need a pull up resistor to get a good signal.

 

[87manche]

https://www.dataq.com/products/di-2108/

that's a generic lab data logger.
but it does never ending data recording to a flash drive.
You'd have to pull the logs and then setup the software to interpret the raw data into RPM.

it's good to 50V on the input, so you'd just have to attach it to that tach signal and set it up to log the pulses.
bonus that you could also use a thermocouple to monitor engine temp at the same time, so you know if someone overheats it.

that's the cheapest on that will operate standalone.

 

[ScottRS]

https://www.summitracing.com/parts/izl-n4026

 

[crispins]

https://www.summitracing.com/parts/izl-n4026

that does not date / time stamp the data, I cannot use something that does not tell me the when

 

[ScottRS]

I don't think you're going to hit your price point and get the features you want in one thing without spending a bunch of time building it out of Arduino or Raspberry Pi or the like. Somewhat full circle, back to 87manche's early post, I think you'll be best-off with either a Speeduino (arduino based DIY EFI) derivative or Pi Dash (raspberry pi based) piggyback'd onto your existing computer. Pi Dash would probably be pretty easy to datalog, just leave out the dash part of it and only use the backend for the datalog. If you're not comfy with doing it though, you're either going to have to spend on something ready-made, or spend on a computer geek to set it up for you. Google up Pi Dash for a bit of reading on that, there are guys out there who've more-or-less scienced out the basics, decide if you're OK with that. Both Arduino and Pi can be adapted to just about whatever inputs you have, converting those inputs (like raw tach pulses) into something meaningful is the trick.

Maybe an old smartphone, Torque, and adapt in what signal you have to one of their bluetooth dongles? Not sure if Torque does pre-OBD-2.

 

[Donk]

I don't think you're going to hit your price point and get the features you want in one thing without spending a bunch of time building it out of Arduino or Raspberry Pi or the like. Somewhat full circle, back to 87manche's early post, I think you'll be best-off with either a Speeduino (arduino based DIY EFI) derivative or Pi Dash (raspberry pi based) piggyback'd onto your existing computer. Pi Dash would probably be pretty easy to datalog, just leave out the dash part of it and only use the backend for the datalog. If you're not comfy with doing it though, you're either going to have to spend on something ready-made, or spend on a computer geek to set it up for you. Google up Pi Dash for a bit of reading on that, there are guys out there who've more-or-less scienced out the basics, decide if you're OK with that. Both Arduino and Pi can be adapted to just about whatever inputs you have, converting those inputs (like raw tach pulses) into something meaningful is the trick.

Maybe an old smartphone, Torque, and adapt in what signal you have to one of their bluetooth dongles? Not sure if Torque does pre-OBD-2.

Op's problem is there's no canbus and the ECU has nothing to do with the tach.
Cheapest solution would be a simple Arduino logger connected to the tach pin in the diag connector, either with a voltage divider or some sort of opto isolation.
Simplest would be use that data logger 87manche linked, dump the data into Excel and let it do the math for you.

 

[87manche]

I don't think you're going to hit your price point and get the features you want in one thing without spending a bunch of time building it out of Arduino or Raspberry Pi or the like. Somewhat full circle, back to 87manche's early post, I think you'll be best-off with either a Speeduino (arduino based DIY EFI) derivative or Pi Dash (raspberry pi based) piggyback'd onto your existing computer. Pi Dash would probably be pretty easy to datalog, just leave out the dash part of it and only use the backend for the datalog. If you're not comfy with doing it though, you're either going to have to spend on something ready-made, or spend on a computer geek to set it up for you. Google up Pi Dash for a bit of reading on that, there are guys out there who've more-or-less scienced out the basics, decide if you're OK with that. Both Arduino and Pi can be adapted to just about whatever inputs you have, converting those inputs (like raw tach pulses) into something meaningful is the trick.

Maybe an old smartphone, Torque, and adapt in what signal you have to one of their bluetooth dongles? Not sure if Torque does pre-OBD-2.

PLX had some stuff that you could piggy back onto their ODB adapter for additional inputs, but I'm not sure if they would work for this. I'm also not sure if you'd ever get torque to actually comunicate with those without the ODB port being present for it to talk to an ECU.

 

[crispins]

Just to update.

The trackers I use have lots of data measuring built into them.

However due to my cars not being OBD2 I do not use much of it.

i wrote them to ask if they could add RPM measurement and a notification if a set limit is exceeded.

They said it might be possible and they would see if they could make it work for me.

They said it would be a month or so.

If it doesn't work out I should still have some time to explore some of the solutions listed here.

 

[2big bronco]

How about a spectrum analizer app on a smartphone set to record? You could have a nice little case for it or mount and just power it up and open the app

 

[mobil1syn]

how easy would it be to convert it to an obd2 engine management system?


https://www.aim-sportline.com/en/products/evo5/index.htm

 

[87manche]

How about a spectrum analizer app on a smartphone set to record? You could have a nice little case for it or mount and just power it up and open the app

that's basically what the data logger I posted is.

if he wants to spend more monies he can get it wireless and shit.

you can't just plug a phone into it. You need some sort of device to actually capture that 12V waveform that's coming from the ignition system.

 

[87manche]

how easy would it be to convert it to an obd2 engine management system?


https://www.aim-sportline.com/en/products/evo5/index.htm

if doing that, why not just put in an ECU that logs it?

you can buy a PNP megasquirt for a miata motor. but it's gonna cost a thousand dollars.

 

[2big bronco]

. You need some sort of device to actually capture that 12V waveform that's coming from the ignition system.

I dont think so... I'm pretty sure a smart phone can recognize the harmonics of the engine and pretty accurately convert to rpm.

Edit: like this

 

[87manche]

I dont think so... I'm pretty sure a smart phone can recognize the harmonics of the engine and pretty accurately convert to rpm.

Edit: like this

lol.

did you read passed the first five bullshit reviews? Cause there's pages and pages of people saying it doesn't work.

https://play.google.com/store/apps/...y.rpmgauge&hl=en_US&gl=US&showAllReviews=true

and even if it did work, it would need to be able to record the exhaust, that comes straight from the developer.

and then how are you going to convince a judge to give you a judgement in the lawsuit based on an app and a smartphone that can't be calibrated or verified?

you use an actual data logging device attached to the actual engine ignition, and assuming that the ecu doesn't cut the ignition when it over speeds, you have an iron clad argument and proof.

 

[2big bronco]

lol.

did you read passed the first five bullshit reviews? Cause there's pages and pages of people saying it doesn't work.

https://play.google.com/store/apps/...y.rpmgauge&hl=en_US&gl=US&showAllReviews=true

and even if it did work, it would need to be able to record the exhaust, that comes straight from the developer.

and then how are you going to convince a judge to give you a judgement in the lawsuit based on an app and a smartphone that can't be calibrated or verified?

you use an actual data logging device attached to the actual engine ignition, and assuming that the ecu doesn't cut the ignition when it over speeds, you have an iron clad argument and proof.

No I didn't read the reviews on that one. Just googled spectrum analizer tachometer app and screenshotted the first one.


Really I think he needs to "reset the data analizer" in front of the customer because hes been having problems with them being over revved on downshifts and needs to start charging the customer when it happens. And people would start driving them more gingerly.

 

[Ebs]

Wire up a 2nd tach in the trunk and put a go pro on it. If it comes back knocking pay someone $10 to watch the most boring video ever and write down the highest number they see.

 

[2big bronco]

Wire up a 2nd tach in the truck and put a go pro on it. If it comes back knocking pay someone $10 to watch the most boring video ever and write down the highest number they see.

Or just install go-pros in the car on the cage. If something comes back knocking you will be able to see exactly what they did to cause it. No "throttle stuck" bs

 

[87manche]

Or just install go-pros in the car on the cage. If something comes back knocking you will be able to see exactly what they did to cause it. No "throttle stuck" bs

that solution was given on the last page, with the additional benefit of having a video to sell to someone after their ride.

try and keep up