you are correct but my problem is it is very difficult to fit my workshop into the x to program the code so my idea is to make everything work on the bench as if it was in the x. so I had to build a test stand and had to adapt a hobby motor to the original speedo I have designed a 3d printed adapter to attach to the original speedo as seen in the video (yes its loud but it is only on the bench and will not be required in the car. that adapter will also hook up to my hall effect sensor that will hook to the original speedo cable and feed to the raspberry pi.
my design is such that it become a direct replacement of the original gauge cluster.
image of the back side
View attachment 52006
the round thing is the magnetic pickup and the hall effect switch for the speedometer
image of my front side of the replacement board
View attachment 52005