Nick's Digital Shed

I always wanted to know how CAN bus worked. I've heard about it in the context of automotive communication back to the early 2000s, when my friend who worked at Halfords, used to regale tails of accidents involving screws and CAN bus wiring, leading to all kinds of unrelated systems suddenly changing their behaviour. I had absolutely no idea how it worked, but understood that it was some kind of network allowing data to be fed around the car using fewer wires than a conventional toggle switch and relay type system. Fast forward many years when I first ECU swapped my first Chimaera for the GEMS control unit, I was introduced to the concept of OBD2 and PIDs (Parameter IDs). I understood that the data was brought in using packets at a reasonably high refresh rate, and that the network was bi-directional; if an error code was sent to my OBD reader, I could send back messages to clear the error. Cool! Moving to my current Chimaera project, I knew that I wanted to use the PIDs output by ...

I spent a huge amount of time considering how to do this right - it's the bit I'm going to be looking at most when I drive the car, so I want it to look good and do the job it's meant to do, and ideally look like something that TVR could have made themselves. It took many iterations to arrive at a design I was happy with; the main issue being the small analogue dials at the bottom of the decal. The two motor hubs are offset from the centre, so if I were to draw an actual semi circle gauge around them, I would end up with an extended circle which looked very odd indeed. The solution was to angle each dash mark toward the real centrepoint of the circle rather than the motor hub, and to stretch the circle into an ellipse. The exact dimensions of the ellipse took forever to get right, so the dial "looks" like a circle as you feel it should be, but the needle doesn't look wrong travelling on a circular track and thus changing its distance to each mark on the dial. ...