Custom square wave output needed.

[DynoDom]

Hello

Is it possible to generate a custom (50/50, 12volt peak, 0-225 hz = 0-100 km/h) square wave signal output in either M150, C1812, PDM30?
This is intended as the vehicle speed signal into an electric assisted power steering.

Wheel speed sensor Inputs and GPS speed are already present on the CANbus.

Thank you in advance.
D

[NathanB]

Hi Dom,

You will use one of the aux outputs on the C1812 for variable frequency:

Frequency control C1812.png (148.83 KiB) Viewed 4774 times

Please note that the aux output will be low side, so you will need to add a pullup to 12V to achieve your square wave.

[DynoDom]

Thank you very much Nathan. PM sent.

[DynoDom]

Hello again with one follow up question:

The manufacturer of the steering unit pointed out that frequency should not exceed 225 Hz.
Our custom Signal ends at 1000Hz.

Do you see a way to freeze the 225Hz at 100 km/h and above?


Thanks in advance,
Dom

[David Ferguson]

A couple of solutions:

- Don't go faster than 225 km/h

- Don't send Ground Speed -- but instead send the output from a table with (ground speed as the input) that has three data points, 0=0, 225=225, and 1000=225.

[DynoDom]

Hi David

It is 225hz at 100 km/h.

I try to achieve the table solution you mentioned.
Thank you,

Dom

[DynoDom]

Hello again

Unfortunately, due to my inability, I failed to create the above mentioned table to freeze the frequency at 225hz when speed is > 100 km/h.

Could you perhaps show a sample of how it is done correctly?


Many thanks in advance.
D

[David Ferguson]

Here is what a 2D table would look like that takes Ground Speed and produced the channel "GP Speed 1 (Lge)"

Speed Cap Table

Speed Cap table.JPG (36.7 KiB) Viewed 4587 times

And here is how your Aux Output would be setup using the "GP Speed 1 (Lge)" channel:

Aux Output Config

Auix Output Config.JPG (36.5 KiB) Viewed 4587 times

[DynoDom]

Thank you David.

[DynoDom]

Good day

The Steering works as intended, thanks to your great support. Thank you very much indeed!

@MoTec
One small Bug in the "monitor dash" is that Aux3 output does not show values, even though the function works.
I just thought to let you know.

Best regards,

D