PDM 30 configuration

[Sydney Chris]

Have been chasing a solution for a PDM programming issue with conflicting results.

The auto elec has wired a three position switch for the headlights via a series of resistors to a single input on the PDM.

The set up is:

[list=]Off = 12V
Parkers = 6V - 9V
Headlights = 5V - 2V
Highbeam = 0V[/list]

The sparkie advises he has wired several PDM's this way and that its possible to configure the PDM to read the voltages across the identified ranges to control the three individually wired outputs for the headlights.

The good gents in Support have had a look and a think but are not aware of a solution at this time.

Appreciate and advice or sample programming where this may have been done before.

With thanks

Chris

[greenamex2]

Would also be really interested in this as well.

Thanks and sorry for "hijacking" your thread.

[Sydney Chris]

All good Denis..

Am here to share..

So far I can trigger the parkers at > 6V and high beam at <1V via the True / False settings on the input.

As far as I can tell I will need to run one additional input for the Low beam unless there is another solution out there.. .

Cheers

Chris

[Sydney Chris]

Have set up a counter for the three position switch... ie:

One = Parkers
Two = Parkers +Low beam
Three = Parkers + Low beam + High

Resets at 12V

Not sure how to decrement though..??

Will trial it tomorrow..

[Sydney Chris]

The input has two states.. one more wire to run for Low Beam... No other solution identified.

[David Ferguson]

Did you try using the voltage channel of the input pin?

In other words use these conditions for each of your three outputs:
highbeamOutput = PDM.Input Voltages.Pin 1 < 1.0

headlightOutput = PDM.Input Voltage.Pin1 >2.0 and PDM.Input Voltage.Pin1 <5.0

parkerOutput = PDM.Input Voltage.Pin1 >6.0 and PDM.Input Voltage.Pin1 < 9.0

I haven't tried this on a real PDM, but it does validate within the MoTeC PDM Manager.

Good Luck!

[Stephen Dean]

Thanks for the information David,

I have loaded the settings into the PDM on the bench here and have been able to use the settings to control multiple outputs using the single input value from a 9 position switch.

You do need to be careful with the voltages and hysteresis as changes in battery voltage can effect the values that are read. You need to have a large voltage range with the voltage output value from the switch sitting as close to the middle of that range as possible to ensure that voltage changes do not make the mode change compared to the switch setting.

[Sydney Chris]

thanks Gents..

Had arrived at a similar conclusion.. had a chance to test it yesterday... as you say, need to ensure there is sufficient voltage range to avoid overlap both with the engine off and when its running.

Cheers

Chris

[greenamex2]

Or feed it a regulated power supply?

USB type 5 volt chargers are tuppence and can easily be gutted to make a cheap regulated 5V supply.

[Sydney Chris]

thanks Denis.. am over the line with the lights.. will keep it in mind

Second and third, issues..

Blinkers / Hazard lights.

I can prove the inputs from the column stalk for L and R, test / enable the outputs via the PDM manager software but not get the flash function to work.

Ive tried flashing the output as a condition when the input is enabled as well as triggering the output to flash from a function when the logical conditions are met with no success. !

Appreciate a post of a sample code for L / R and Hazards if possible.

The last issue.. for now.. !! lol is the speed sensor. Ive fitted a Honeywell three wire speed sensor to the tail shaft to simply be able to detect when the car is moving (it has logical linkages to the alarm chime, door switches etc and an engine cooling fan which is supposed to run at low speed).

What function / condition is recommended to be able to count / average the pulses to get a rough equivalent for speed..?

With thanks

Chris