One of the most popular modifications for MX-5 RF is adding the “SmartTop” module made by mods4cars. This is a very simple electronic device, but it cost over $300, I think because there is no competition. I decided to design and produce my own version of such a device. Basically, it is just a CAN bus bridge, which can filter can messages, to trick the roof mechanism by blocking messages which will disable operation (like higher speed, car in reverse, etc). My previous project for the front camera kit has a similar design, so it was easy to reuse it for this project.
Implementing a one-touch feature is very simple as well, because the roof control switch produces only two voltage levels, to keep the roof opening or closing.
Another idea for this device is to be able to control the roof using the key fob like it is done in BMW Z4 for example. So you open the roof while approaching the car. This is quite a challenging task because the roof mechanism operates only when Ignition power is on and other modules on the CAN bus operational. I’m hoping to override these limitations by integrating the IG power switch for the roof controller in my device and substitute the CAN messages for initial communication.
My first version of this device now operational for all basic features. The software can be updated at any time via USB cable. To do this, my son made for me a Windows application.
Because I have to have communication with Key Fob, I found that it would be useful to have different configurations assigned for each key fob. If you need to give the car to someone else, you can share a key that has disabled the new feature, to avoid confusion at the service center for example. Or for valet parking, you can share the key with completely disabled roof control, so they can’t play with this feature.
Hardware installation will be exactly the same as for “SmartTop”, YouTube has tons of videos on how to do this.
The module it self 50mm x 59mm x 18mm. It has a Micro USB connector for programming, LED status and a 16 pin connector for the main harness, similar to “SmartTop” is using. This device with a harness will be available in my store for $159.
Gadgets for my MX-5 Miata (ND) 
Any idea when this will be available?
LikeLike
probably next month, limited numbers. More in July
LikeLike
So, does this means that it will be posible to implement the option to close windows all the way up after the roof is closed?
LikeLike
this is the function of other our product https://mx5things.com/collections/mazda-mx-5-rf/products/automatic-roll-up-windows-controller-for-rf?variant=39439285026980
LikeLike
OK. I thought that it was not able to close windows completely because it did not know if the roof was moving. I mean when closing the roof normally, no key fob.
LikeLike
I got confused because of this statement on the RF windows controller description “Lock operation will lift the windows if there is a gap left after the operation with the roof (NA cars only)” What does “NA cars only” mean in this context.
LikeLike
NA – North America, other markets (Europe, Japan) do not have this issue
LikeLike
I see. Thanks!
LikeLike
Pingback: Opening and closing RF roof with a key fob | Gadgets for my MX-5 Miata (ND)
Pingback: Opening and closing RF roof with a key fob | Gadgets for my MX-5 Miata (ND)
Do you need a Windows computer to program the various options of this device or update it?
LikeLike
yes, currently only Windows supported, but we are working on the MAC version as well.
LikeLike
Your solution sounds like a great upgrade to ND, but I can’t help wondering if the secondary immobilizer routinely installed by Mazda dealerships in some countries (i.e. in Poland) isn’t going to prevent it from operating remotely. Do you have any experience with those? Thanks for the awesome initiative anyhow. 🙂
LikeLike
sorry, I have no idea what is this and how it works
LikeLike
Pingback: Speed Correction Module | Gadgets for my MX-5 Miata (ND)
I’m guessing this only works for the ND? Could it be modified to work for the NC? Because I would absolutely kill for the functionality of this + your remote opener
LikeLike
I have an option for NC, but the remote operation is not possible in NC, because it has a manual roof latch
LikeLike
Is it possible to get the NC version to work with automatic trans? I am a programmer myself and would be willing to figure this out.
LikeLike
I need to figure out the CAN message for the shift position in AT
LikeLike
CAN-H is pin 1S and CAN-L is pin 1U on the larger of the 3 plugs. But you said you dont have access to a AT miata.
LikeLike
It is not a connection issue. The hardware is identical for MT and AT, but the CAN messaging is different, and I don’t have anyone with AT near me to do a CAN scan for AT version.
LikeLike
Exactly. I see the issue I didn’t know the CAN messaging is different. So then does the SmartTop controller module look for both messaging types? If only you know both transmission messages you could just program the module to figure out which car it’s in and act accordingly I presume.
LikeLike
correct
LikeLike
Awesome looking forward to the software update. How will I know when its complete? And how do I download the .dat file?
LikeLike
Is there any way I can scan my car for you?
LikeLike
I have one customer with a scanner. He is going to scan by the end of this month.
LikeLike
Too bad I don’t have an oscilloscope on hand.
LikeLike
So I guess that’s why the SmartTop costs more I wanted to get your device but I drive AT so i guess I’m just gonna have to pay a little more to get this to work then. Thanks and good work with this device anyway.
LikeLike
Any news on the Automatic Trans update?
LikeLike
Current software support AT and MT
LikeLike