Arduino Projects

[Dave 53]

My daughter is pretty handy with Arduino and has offered to make me an LED tach / shift light bar. What's the best way to get RPM data into Arduino? I see pin C9 on my 2002 WRX ECU is "Tach Signal". What exactly is pin C9 sending to the ECU? A voltage pulse each revolution or a momentary closed switch each revolution maybe?

I've found OBD2 to Arduino plugs, but also have seen chatter about "SSM" (I have no idea what SSM is). What's the best / easiest way to get RPM data into Arduino?

Are there any other cool Arduino projects? Maybe have Arduino turn on the AWIC pump? Turbo timer - keep the car running a few minutes after turning the key off?

[chmhasy]

Not sure what SSM is, You may need to use some type of isolation from the cars voltage to the Arduino voltage in-pins like a Opto-isolator.

There is a bunch of projects that can be built with the Arduino, www.arduino.cc, www.adafruit.com www.sparkfun.com
and you can build virtual arduino projects with this site www.tinkercad.com in the circuit area.

[Ajzride]

The Subaru ECU does not talk traditional CAN, it talks SSM. You can get an Arduino to talk SSM, I have one running my whole gauge cluster for custom digital gauges.

https://thefactoryfiveforum.com/showthread.php?34088-Subaru-SSM-to-Can-Bus-Convertor-DIY

If you want to pick up a tach signal raw and feed it to the Arduino, you will need to get creative. The ECU puts out 12V and the Arduino reads 5V, tying the tach in without a voltage divider will fry the Arduino. Not sure what kind of voltage divider would keep up with the speed of a tach signal.

I also have a second Arduino in the controlling my electric parking brake motors.

[Larry J W]

Not sure but I think the 2010+ Subaru use the canbus system. I will find out in the next few weeks while trying to decode their communication system. The goal is to fool a stock ez36 ecu to run in a 818. It is a real long shot. The worst case is I learn a lot! The backup plan is a megasquirt.
Larry

[Hobby Racer]

The goal is to fool a stock ez36 ecu to run in a 818. It is a real long shot. The worst case is I learn a lot! The backup plan is a megasquirt.
Larry

If you go MegaSquirt, I can help as I pioneered running the EZ36 on MegaSquirt :D

[Ajzride]

Check out RomRaiders forum, they have a great breakdown of all the ECUs by year with their protocols. I know the newer engines have been put in the 818. I think I saw a 2014 on the Facebook page.

[mikeb75]

My daughter is pretty handy with Arduino and has offered to make me an LED tach / shift light bar. What's the best way to get RPM data into Arduino? I see pin C9 on my 2002 WRX ECU is "Tach Signal". What exactly is pin C9 sending to the ECU? A voltage pulse each revolution or a momentary closed switch each revolution maybe?

I have tied C9 into my data logger (RaceCapture/PRO), according to their documentation:


RaceCapture/Pro requires a relatively clean square wave signal in the range of 0-5v to 0-24v.

https://wiki.autosportlabs.com/RaceCapturePro_RPM
(there is a bit more information I need to get from my logger to give details on the pulse/RPM conversion)

There is some other information here (I believe Ajzride has done most of the pioneering work for Subaru SSM - a protocol to query the subaru ECU for data) to Arduino. I've just started working on a similar solution using other work to get data from the ECU and broadcast it via the CAN BUS protocol based on information posted in this project: https://github.com/rpkish/Subduino-SSM