[Adam_86]

HI, I have started my first PCB today to make a BOB from a speeduino V0.4 to a 97 miata stock ecu harness. I no experience with speeduino or other ECU. I have a basic knowledge of electronics and programming. Here's my electronic schematic for the connectors. the 4 pins one is for the wideband.

My questions.
Is it a good idea to use an existent plug and wire to do boost control (ex: use EGR plug to connect boost solenoid)?
Do the chassis ground and sensors ground go to the ground plane on the PCB?
On what pin do a put the VSS?
Do the Water Meth Injection take the VVT output?
Is it ok to take the 12v for the wideband there or it is best to take another source?



1997 miata connector for reference

[jonbill]

You haven't shared your images in google photos, so only you can see them!

[Adam_86]

You haven't shared your images in google photos, so only you can see them!

Oups, thx fixed now?

and what input for the oil pressure if I install a sensor?

[theonewithin]

You haven't shared your images in google photos, so only you can see them!

Oups, thx fixed now?

and what input for the oil pressure if I install a sensor?

Any free Analog input.

Copy existing input as per the schematic is recommended.

[theonewithin]

My questions.
Is it a good idea to use an existent plug and wire to do boost control (ex: use EGR plug to connect boost solenoid)?

That's up to you.

Do the chassis ground and sensors ground go to the ground plane on the PCB?

Yes. There is only 1 ground.

On what pin do a put the VSS?

Any spare interrupt capable input. Make sure provision for VR conditioner is added if required.|

Do the Water Meth Injection take the VVT output?

I don't understand this? Could you repeat question?

Is it ok to take the 12v for the wideband there or it is best to take another source?

Depends....

Is there enough 12V power being supplied. If not you will need to find another way to supply it to ensure fuse's don't blow/wiring doesn't catch on fire.

[Adam_86]

Thx for the answers theonewithin.

So I can use the default ethanol sensor pin for VSS and set it in Tuner studio? Pin 2 on the mega

I did some more research so the VVT table is shared with the WMI so only one can be used at a time.
I will use the VVT pin for the PWM of the WMI for simplicity.

So if a need an analog input I just solder a wire to an empty analog pin of the arduino to the proto area and feed the sensor signal and set it in Tuner Studio right?

If I copy the RC filter used in the board design I presume Its ok? I will add this to my board with the SP721 for overvoltage protection. I want to add fuel pressure and oil pressure.



And for Digital I/O is the same I presume, with a pull up or down resistor.

And found the default pins for the v0.4

[tgrossb]

I'm also working on installing my 0.4 into my 97 miata with the stock ecu harness. How's this project going?

[Adam_86]

I'm also working on installing my 0.4 into my 97 miata with the stock ecu harness. How's this project going?

sorry for the late reply.
I bought a UA4C instead of the v0.4. I just ordered my pcbs and connectors today. I will design a case and print it in the next few weeks.

[waktaylor]

Great work. I just did a similar setup the hard way.

Have you installed in car?

[Adam_86]

sorry for the late reply I am not here often. Yes I installed it in the car and it went great.



And I made a display for the speeduino data, it communicate via serial and has an SD card for data logging.