Hello,
I want to operate the OMP (oil metering pump) from an Rx7 FD. It is a stepper with a 5V feedback pin.
The stepper can do 200 steps. 0 steps are ~0.90 and 200 steps are ~4.40 volts. Any idea how to do this in the project tree in combination with the custom stepper function?
Today, we released the 219.0‑beta software. It now supports a custom stepper motor operating in closed‑loop mode with a sensor. The Custom Stepper Motor Position sensor can be configured in the SENSORS tab.
I have one more question regarding my setup.
How should I configure the ECU to drive a unipolar stepper motor (6-wire type, with the ECU side connected to GND)?
Are there any specific wiring considerations, output mode settings, or step/phase configurations I should be aware of for proper operation?
I want to make sure I’m not missing any key ECU parameters before testing.
You can use it as a bipolar stepper motor.
It will provide better torque than the unipolar configuration.
But requires two full H-bridges to drive it.
You leave the middle taps unconnected.
Unipolar configuration can be controlled with low-side outputs only (injector, auxiliary), but we don’t have support for that currently.
The only crucial setting is the polarity of H-bridge outputs.
There are two settings to invert the outputs.
One of four combinations is correct.
With wrong settings, the stepper motor will not move consistently or move in the wrong direction.
Step frequency changes the actuation speed.
A step frequency too high will result in lost steps during movement.
PWM hold settings are for situations when the stepper is holding a constant position.
Higher hold DC will result in higher holding torque and higher temperature rise.
Lower hold DC will result in lower holding torque and lower temperature rise.
This is something you have to play around with and calibrate.
We don’t have access to the metering pump for calibration and testing.
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