The component count for the op amp version would be, roughly:-
1 Op amp
4 resistors
1 capacitor
1 driver transistor
1 relay
wire
small piece stripboard
I think something this simple is easily repeatable by other EV'ers who dont have any expertise in electronics as a DIY job.
I accept completely that the adition of a simple switch at the top of the accelerator pedal travel is probably the simplest and least elegant and least functional. As you say the brake light would be on whenever the ignition was on and you are not pressing the pedal - although I think Chris suggested a simple timer type relay that would only keep the brake light on for some user adjusted time interval.
As with everthing in life it is a compromise. I guess at the lowest end it is a simple switch and then in various degrees we have analogue or digital electronics. If you are keen to use a PIC then its always good to have a real project to do to focus ones mind on how a particular micro is best utilised.
I guess thats my 2mA worth...
I think I will try the simple switch first - then the op amp then maybe incorporate it into a micro design that could also monitor other parameters in the drive train - but then the Evlite started out like this....
![Rolling Eyes :roll:](./images/smilies/icon_rolleyes.gif)
So how easy is it to get the dash out to get to the back of the eco meter?