I’ve wanted to do a slick virtual gauge cluster for the Miata for a while now. I think I’ve finally figured out how I’m going to go about it.
- Android Tablet
- Arduino (Pro Micro)
- Non-functional NA6 Gauge cluster from Ebay
- Megasquirt PNP
- Some 3D printed buttons to “look stockish” for controlling screen
- 12V DC to 5V USB adapter
- USB On-The-Go (OTG) Hub with Power for Device (basically a fancy hub that lets you charge while using USB OTG
- Some nice new bezel for the screen
- USB to RS232 Serial cable
- RealDash for Android
- Android power-on plug-in mode
- Android power-off when unplugged macro
- Macro to auto-launch RealDash on boot
So the simple part is using RealDash. It actually seems to be some great software. The tough part is that the Miata doesn’t have OBD2, let alone a CAN Bus. What does, however, is Megasquirt - which is RealDash compatible. I tested RealDash tonight with my Lancer and a wired ELM237 OBD2 reader (RS232 Serial over USB) and a USB OTG cable, and it worked great.
But here’s the thing, I want it to look quite factory and just shoving a tablet with a bunch wires into the car isn’t going to do. So I bought a broken NA6 Miata gauge cluster/pod on Ebay for $15. I’ll pull the old bits out and fabricate a nice bezel for around the screen and to hold the screen into the pod. I will keep the plastic lens to keep dust out and retain the stock look while the car is off.
Since it will be integrated with the dash, I have two small problems. First, I’ll need to have power running to it. Thankfully, there are plenty of places to get some of that sweet 12V DC in the Miata (ash tray lights, ignition, RADIO THAT DOESN’T WORK, etc). Second, I’ll need a way to control it in case I want to switch modes etc. There are a couple of ways to do this, but I think the best and stealthiest way to do it is to use a Pro Micro from Sparkfun to emulate keyboard shortcuts (like D-pad right/left - which RealDash has hotkeys for more switching layouts). I can then build some basic buttons for controlling basic functions. I’ll probably hide a USB port somewhere for plugging in a rescue mouse in case something goes wrong.
The overall cost will be pretty high, but only because a Megasquirt PNP is expensive. Everything else should be under $350 total depending on whether a recycle a tablet or not.