Yes, you would need a LCR meter (so you can measure inductance). If you get the inductance the same it should work, but that’s why off the shelf won’t work unless you get particularly lucky.
This post has some good information, there able to get away with not having a LCR meter as the device there adding it too can measure the antenna characteristics itself.
So to simplify this and not having to worry about the antenna, I think I’m just going to get a second xAC v2. Here’s my plan, and please let me know if anyone sees any issues with it or a better way.
Solder 2 wires (+ and -) to the key fob, from this wire set, solder an additional + and - for the second xAC v2. One xAC will be at the front drivers window, the second xAC will be at the rear drivers window (or possibly passenger side)
What are you connecting it to on the fob? I doubt your fob conveniently has a place you can pump power into that will both power it and press the button. You shouldn’t need a battery, you could power it from the car but the fob probably expects a 1.5v button cell, you’d want a voltage regulator hooked up to 12v from your car. As for activating the button, you can’t just dump power into the button pins, that’s a great way to release the magic smoke from your fob, you’d want a relay or MOSFET of some sort to replace the button.
(sorry not an electrical engineer so may be wrong with terminology etc)
@NiamhAstra looks like he is replying to you ( A couple of issues with your plan, or things to confirm ), I will leave him to it, but I will give you the measurements…standby
Call it 105mm x 55mm to be safe
FYI xEM is implant xAC is the access controller V2
Right sorry, 2 am and my mind isn’t working clearly lol I’ll edit the post to avoid confusion. Thanks for the measurement. Is that the v2? That is the one I ordered as the original is out of stock.
Yes, directly to the fob. I can’t really see another way to do it. My original plan was to tap into my compustar unit to unlock/disarm the alarm but I don’t think there’s a disarm input from what I saw. That’s going to be the issue. I can run it to the lock wires to unlock but that won’t disarm the alarm. Seems like this is going to be more complicated than I thought
@Pilgrimsmaster I’m sleepy and can’t find the Toggilator mainly because I can’t spell it… Could you “tap in” . I feel like all the information around that thing is very relevant here.
Haha yeah I’m sleepy too clearly, I had myself convinced that the fob battery was 9v and I could just tap into it but you are correct it’s the 1.5v I believe.
I was reading about that on the forum and the possible production of it. Did it happen? I’m going to go and order that now if that’s the case
@Devilclarke was the mastermind behind it. He is an electrical engineer and made a batch. Not sure if it progressed beyond his prototypes. Maybe this message will summon him.
It is a thing,
Last I heard @Devilclarke was still waiting for the Potentiometers pots, then they will be a thing.
I am not sure how far in talks it got, but DevilClarke and Amal were considering putting a DT Access controller together to bring to market, but that may be some time away. I am not sure if the xAC V2 is THE new thing or just a stopgap until the DevilAmal AC Colab…
And then here’s the original idea, from my compustar, I thought it was input so I thought perfect this will be easy. It’s actually output to the lock so I don’t know how I’d ever get it to work but I’m not hopeful
Even then though I don’t know how I’d get the xAC to tell the compustar to unlock and disarm. I think they are assuming a key fob is being used with that wire
Although this is almost a mute point right now with the xac2. The rev 2 boards have been assembled however due to work and home have been unable to test.
I was thinking of making a simpler version using an atmega instead as this would be simpler and cheaper for a short run if wanted.