I've just finished adding a programmable rev gauge to my carbon centre speedo. All the hard programming work was the handy work of Chippernut
I built v2.31 of Chippernut's project on a protoboard and decided to make the 7-segment display and rotary encoder removable.
Here are a few pictures of the build process.
I have been playing around with an Arduino for a little while now attempting to make my own gear position indicator and here is the almost finished product.
It consists of a 1.3" OLED mounted inside a re-purposed Smiths oil temp gauge that I picked up on theminiforum.co.uk for £10. I have gone down this route so that the gauge looks "factory" once installed and isn't obvious what it is. It will be installed in my carbon fibre centre binnacle.