For anything not related to Speeduino, but still about car/bike/boat/engines etc
By Izzy46
I would like to bypass the computer that controls the gauges on my 2005 Mastercraft boat. My main reason for this is that the computer is water damaged and a replacement in around $3000. The gauges are new and I have an old set to experiment with.

The legacy gauge setup takes an analogue signal from the fuel sender, tach, oil pressure, temperature, voltage and gps for the speedo. The signal is then converted into a digital signal by the $3000 computer and then sent through a single cable to all of the gauges. Each gauge has a chip that handshakes with the digital signal taking the required data and using it to move a stepper motor that moves the gauge needle.

The gauge functionality is explained in the link below.

I've thought about replacing the setup with analogue gauges but size and color of the gauges won't match or fit the current setup.

My plan is to cut the back off the current gauges and communicate directly with the gauge stepper motors using an Arduino and a motor controller.
IMG_20230212_061912_341.jpg (1.8 MiB) Viewed 5110 times
IMG_20230212_061912_341.jpg (1.8 MiB) Viewed 5110 times
The four pins that control the two stepper motor coils seem to be easily accessible. I imagine I could simply solder a cable on to the back of each pin and then connect it to a stepper motor driver?

Is this idea at all feasible or is it possible to replicate the protocol from the dead computer and communicate with the gauges directly...?

Any ideas would be appreciated, thanks. :) :) :)
IMG_20230212_061428_198.jpg (2.48 MiB) Viewed 5110 times
User avatar
Sounds like a straightforward plan. You can do a search for some info where some of us have done stepper gauges here before, through buffers or directly from Arduino. Your coil properties will dictate which you can do. Have fun!
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