MoTeC Global Forum

To all,

I'm trying to figure out if I'm missing something when using AUX1-4 on my C125.

What I'd like to do is have AUX1 -as an example - ON (low voltage/ground) and OFF (no voltage) to create more of a status signal.

Is this a possibility or am I stuck running a relay or just sticking with a switch?

The goal is to use a keypad to drive the output - already completed for another channel that requires a 12v signal.

Thank you!

-

Trever

What are you trying to drive with the output? I was doing similar with my C127 though it was actually being used to drive a relay. I was using it to trigger power to a camera when the logger was active.

If it is coming from a keypad, do you mean a keypad attached to a PDM? You can bring the button press directly into the dash over CAN but in general I found it easier to just have the PDM send the button status over CAN along with other messages to the dash.

the_bluester wrote:What are you trying to drive with the output? I was doing similar with my C127 though it was actually being used to drive a relay. I was using it to trigger power to a camera when the logger was active.

If it is coming from a keypad, do you mean a keypad attached to a PDM? You can bring the button press directly into the dash over CAN but in general I found it easier to just have the PDM send the button status over CAN along with other messages to the dash.

I'd like to use the C125 to send a status signal for brake pedal On/Off and DSC On/Off to the MK60 ABS/DSC system - removing a couple of relays from the car. The MK60 needs a ground signal when the brake pedal is at rest and no contact when pressed.

The other is essentially the same, but I'll be using a RG Rotary Keypad to change DSC On/Off.

I assume you would have the brake light switch connected to one of the Aux inputs and have that set up as a brake switch input? Can you see that input status in your config? If so you can use it to drive the output easily enough (I am assuming here you have the I/O upgrade?)

the_bluester wrote:I assume you would have the brake light switch connected to one of the Aux inputs and have that set up as a brake switch input? Can you see that input status in your config? If so you can use it to drive the output easily enough (I am assuming here you have the I/O upgrade?)

Correct and I do have the I/O upgrade.

Brake Status is wired to DIG1. The inputs aren't the problem.

I was playing around with AUXOUT3 - example - this afternoon and and it only works as 12v or ground.

At least the brake light signal should work for you then, set up the digital input as a switch and use that input to drive the aux output, make that active for whichever switch input state you have set up for when the input goes high.

When the aux output is on it will pull to ground, providing your earth/0V to your MK60. If it does not float high enough to be seen as "Off" when the aux output it off you might need a pull up resistor on the output.

EDIT: I have not looked into the aux outputs on the dashes, you might want to check how it behaves when powered off, a lot of ECU aux outputs for instance rest at 0V when powered off.

the_bluester wrote:At least the brake light signal should work for you then, set up the digital input as a switch and use that input to drive the aux output, make that active for whichever switch input state you have set up for when the input goes high.

When the aux output is on it will pull to ground, providing your earth/0V to your MK60. If it does not float high enough to be seen as "Off" when the aux output it off you might need a pull up resistor on the output.

EDIT: I have not looked into the aux outputs on the dashes, you might want to check how it behaves when powered off, a lot of ECU aux outputs for instance rest at 0V when powered off.

Unfortunately in the off state it's 12v when driving low and the inverse when driving high...

I was hoping that when driving low there would be a no contact option I'm missing.

I might just use a relay and be done with it.

The outputs on the C1xx Dashes have a 10k pullup to battery positive, this is causing the 12V reading when the output is off.

Is there a reason you can't have 12V on the pin when the output is off?

adrian wrote:The outputs on the C1xx Dashes have a 10k pullup to battery positive, this is causing the 12V reading when the output is off.

Is there a reason you can't have 12V on the pin when the output is off?

The Teves MK60 used in the E46 - and various other models - needs constant ground when not braking (pedal at rest) and open (pedal pressed). I have multiple options for this one, but it would be nice to use the dash.

The other - same issue - is the brake fluid switch. We're using the brake fluid input as a complete deactivation of the DSC system. Active when switched to ground and not when open.

I'm not sure I understand the problem. You have the output active when the input is inactive (grounding the module when the pedal is not pressed) and then deactivate the output when the pedal is pressed (open circuit output when pedal is pressed).

I have never used these modules before but I would be surprised if the approx 1mA that could be drawn through the 10k pullup in the open condition could cause an issue.