Megasquirt Support Forum (MSEXTRA)

Hi, i'm lookin for the way to controll Generic stepper motors.

For example:
1. oil metering pump on rotary mazdas. 6-wire stepper motor with position sensor (same type as TPS)
2. toyota electronic throttle valve ETCS-i. 4-wire stepper motor with two position sensors - one for actual throttle valve position, one for pedal position.

It would be great if newer MS3 firmwares will have feature similar to Generic PWM output, for controlling steppers using table with target position depending on engine speed / load or other conditions (sutch as coolant temperature, etc)
for second example - ETCS-i in newer toyotas have not independed idle valve, so stepper must not just follow the pedal position, but also control idle speed.

IMHO controlling electronic throttles is actual, because more & more newer cars have this feature.

P.S. I can help with beta-tests

This is what AEM dos,

It has a few checks like under and over voltage, where the outputs disable.

AEM dos not offer things like cruse control and torque limiting by reducing throttle opening.
It is these programs that quickly bring in the ability for cars to run away.

They're planning to add dedicated OMP stepper control code to 1.3 code.

Drive by wire would be more of a purpose written function and there are a couple other threads covering it.

Matt Cramer wrote:They're planning to add dedicated OMP stepper control code to 1.3 code.

Any news on this ??

I have not done it yet. It is still on the list.

juansh2385 wrote:

Matt Cramer wrote:They're planning to add dedicated OMP stepper control code to 1.3 code.

Any news on this ??

I've done it myself. Work perfect on my '92 FD. It will be great if my part of code will included in next MS3 firmware release.

It won't make 1.3. A version that interacts with my generic closed loop code will be integrated probably for 1.4.

Did omp control by anychance make it into 1.4? if so I'll be pick up another MS3 to test this out.

not yet, but it will.

Ken - I just measured an FD OMP and an RX-8 OMP. The FD OMP has 44 ohms per coil, and the RX-8 has 66 ohms per coil. The datasheet for the UDN2916 states 750mA continuous output current - isn't that well above the current that these pumps will draw? Meaning, they can work with the MS3's stepper circuit as-is.