I did small update to the code. There was a problem with update rate being about 9hz and it caused data to be out of sync.
I changed it to 10hz and now data should stay at sync.

edit. still needed small fix, but now it should be ok.

 

Code updated. Still had some problems with update rate what caused sensor data to be out of sync.
Now I used millis function instead of delay. It helped quite a lot. Still not perfect. After 30min logging session data is out of sync by 2 seconds. This is probably best what I can achieve with Arduino hardware without rtc or gps.

 

I'd like to datalog my oil pressure and temp too, I should look into this; I'm a total newb when it comes to all of this though, any idea if this would work on an iphone (BT likely not going to be usable though)? Also, the gauge is optional right?

 

Doesn't work with iPhone because of old Bluetooth protocol. You would need to use Bluetooth Low Energy protocol. Code needs to be totally different and Bluetooth module should be compatible with Bluetooth LE.
One project where Bluetooth LE is used: https://github.com/aollin/racechrono-ble-diy-device/

Yes the gauge is optional. I wanted gauge because I replaced oil pressure switch with pressure sensor.

 

OOF! Damn, oh well, too complicated for me to figure out. My friend suggested that I get the RaceCapture/Track and add the AnalogX, which will allow me to connect upto 4 sensors. That seems like the most cost effective solution, the only thing is that it's not exactly plug and play either. Keep up the good work though!

 

I have copied this code to my arduino.
Only the temp sensors code.
​​​​​​
I have now a problem. I want to use 3 same kind of temp sensors. Radiator coolant sensor down and radiator coolant sensor in the top of the radiator. Also i want to plug a oil temp sensor.

I have now a problem. I print the temps to lcd but somewhere in the code there is a fault that if i have only one sensor pluged in so it show the current temp but the sensor 2 will show 10 grades higher temperature even its not connected to analogread input. Can someone tell me why?

If i only copy the temp of the starters code once with only one temp sensor and i take the analog read wire out the temp goes to 0°c. Thats good but why if i have 2 sensors in the code and i take all of the analogread wires out the temp of the both analogreads clibs to 100°c....?
I can link my code if someone can help me do the code right that i can control my radiator fans

 

So you are not using Racechrono on your project? In this case my project won't help much.

With adc pins without any kind of pull up / pull down resistors there can appear some floating voltages that cause fault readings if there isn't anything connected.

Please share your project goal, code and wiring. I can take a look.

 

At the start i want to se my temperatures in LCD. Upper radiator/bottom of the radiator and maybe the oil temp.
then i will control my fan relay via a mosfet.
The code is now littlebit hazard because i have tryed everything...
Dont no how to attach the. .ino file here but i can send it to email?

 

You could use file sharing service like Google Drive, Dropbox etc.
https://blog.bit.ai/free-file-sharing-sites/

 

https://drive.google.com/file/d/1Vad...w?usp=drivesdk

There you can see the code