Contact inputs on SV harness

[swatson999]

I just connected a couple of the contact inputs on the harness, but now that I read closer, I think I'm seeing that those are currently not implemented...is that right? If so, I should move the two contacts (starter engaged and alternator failure) to a couple of the General Purpose lines on the EMS DB-37 connector?

It's easy enough to do, just want to confirm that those Contact Inputs 1-4 are currently disabled on the SV main harness...

 

[dynonsupport]

True. Those contacts are not implemented in software. Many of the EMS inputs can be set up to behave as contact inputs though.

 

[swatson999]

Coolomundo...will rewire them up and set up the sensors/display tonight!

Any word on when those inputs will become operational? (Say, about the time the AOA calculations use flap position hint hint? )

 

[swatson999]

So after rewiring, and then configuring the sensors on pins 20 and 21 for contact inputs, I read that the max a contact input can see is 5V. Fair enough, I set that up.

Here's the odd part, though...neither of my two new contact input lines, the alternator out line or the "I" post on the starter relay, are showing anywhere close to 0. The alternator line is the 2V range, even when there is no field on the alternator (keep in mind this is all still in the garage, not with the engine running), and the starter I signal shows nearly 5V. I'm looking at the sensor debug screen.

What am I doing wrong? All other sensors appear to be working just fine (pressure, temperature, MAP, RPM, etc.).

I would have expected near 0 voltage on both, with the starter (e.g.) going to 12V when on. It does that (per my meter), but why is it showing 5V?

 

[dynonsupport]

The contact inputs have a 10K pull-up resistor to 5V. The assumption is that what is hooked to them will either be open or a short to ground.

Because of this, it reads 5V with nothing hooked to it, and 0V when shorted to ground.

Active devices like a alternator output may not follow this, as they may try and output 12V when on, but are effectively connected to nothing when off, and we'll read 5V in that case.

But that's OK, it's easy to fix. What you want to do is hook a 1K resistor to ground. This will make the input read about .5V when nothing is connected, but if something tries to drive this to 5V or 12V, then you'll read that voltage. Then you can leave the contact threshold at 2.5V and it will work like you want.

In the specific case of your alternator, it probably reads 2V when off and 12V when on. That works just fine for us- set your threshold up at 3V or 4V, and you'll get the indication you want.

 

[swatson999]

But that's OK, it's easy to fix. What you want to do is hook a 1K resistor to ground. This will make the input read about .5V when nothing is connected, but if something tries to drive this to 5V or 12V, then you'll read that voltage. Then you can leave the contact threshold at 2.5V and it will work like you want.

OK, I'm a newbie at electronics (I'm a software guy), so I don't quite know what this means in my case. I have a single wire from the "I" post on the relay to the GP pin on the EMS DB-37 (I think it's pin 20). Where exactly would I put this resistor?

I know this is probably a dumb question for most people here, but I appreciate all of your help.

 

[dynonsupport]

Anywhere between the device's output and before our input. IE:

Device-----------------|---------Dynon
                               |
                               |
                              1K
                               |
                               |
                               |
                           Ground

 

[Leon_Joubert]

From one of your posts: "The contact inputs have a 10K pull-up resistor to 5V."
I have linear Pot sliding with the Flaps but the top is supplied with 2.5V from the flap controller which reads it. Connecting it directly to EMS input would alter the slider voltage due to the 10k internal EMS pullup. Would it work if I buffer the slider signal with an op-amp (47 ohm output impedance) and then feed it to the EMS input?
P.S. I have similar requirements from 3 other trim motor controllers so there aren't enough C type inputs anyway that's why I need this scheme.

 

[dynonsupport]

Buffering with an op-amp should work.

 

[mmarien]

I'm trying to figure this out for my device. I have a toggle switch (ON - OFF) with an indicator LED that controls a relay that switches between pumps. On the (SPDT) relay NC is pump #1. NO is pump #2. The toggle switch is powered (12V - 1A fuse). Switching the toggle switch ON lights up the LED and switches the relay to NO to power pump #2.

What is the best way to connect an EMS contact to display which pump is active? If I connect the EMS contact pin to the switched side of the toggle switch do I need the 1K resistor? On the switched side of the toggle switch do I connect the wire to the relay, a 1K resistor to GND and the EMS contact all to the same point? or is the EMS contact connected to the GND side of the resistor? What size of 1K resistor do I need? 1/4 watt? 1/2 watt?

 

[dynonsupport]

If you just hook the EMS input to the switched side of the toggle switch it will work. You'll get 12V when it's on (pump 2) and approx 0V when it's off (pump 1). You don't need any resistors, since you have a relay, and that's effectively a low-ohm resistor to ground.

In the SkyView setup, you can leave the contact threshold at the default of 2.5V, and define the lower than 2.5V range as pump 1 and above 2.5V as pump 2.

 

[mmarien]

Thanks.

I did go down to the electronics shop and they worked out what I needed to do, but this is a lot simpler method.

 

[cleesgt]

I'd like to use the SV-harness contact pins 14, 15, 27 & 28 for pitot heat on, fuel pump 1 & 2 on, etc. I've maxed out the EMS harness pins. I've reviewed the installation manual, and searched through the D1000 set-up screens, but don't see how to access and set-up the SV-harness C37_P14/15/27/28 pins. Any advice?

 

[dynonsupport]

The contacts on the SkyView screen are not currently supported in software currently. If we do support them in the future the current intent wasn't to use them for EMS inputs but for other things, but we can consider this if er get more requests.

 

[cleesgt]

On using the SV harness 'contact' pins 14/15/27/28, I now realize the aren't programmed according to the notes above. Any word on when they'll be available? I'd like to wire sensors and wait...if that's reasonable. Thanks.

 

[dynonsupport]

As mentioned, we don't currently have any plans to use these for EMS contact inputs. This can change if we get enough customer requests.

 

[swatson999]

Consider it requested...