Showing Indicators on LCD(suggest am i right?)

im interfacing the arduino with my bike , The bike's electrical stuff runs on 12v so to show indicators on the lcd i will be changing current flowing to indicator(left right) switch to 5v from the voltage regualtor and then the switch to arduino analog pin so that the arduino gets the command in analog pin and lcd could be driven and the indicator Bulbs are given power through TO-220 transistors.

The bikes indicator switch works like >> left--off--right

I think this would work pretty fine ,What you guys suggest/think?

sorry
read that a couple of times
each word makes sense
but not in that order!

Actually im showing indicator symbols on LCD STN koIoB driver type one so for that to happen Uc must know when to show the symbols so as such the switches have to have 5v running in them so they can be interfaced with the Uc and transistor To-220 to switch high currents such as 12v dc that runs in bikes battery.

I recognize English is not your first language. Please help us by at least breaking up your thoughts into sentences, using periods. This may allow others to translate what you are trying to ask.

Im saying my idea is to run 5volt DC power(replacing 12v dc power) through switch used to control indicators on the bike
so that input can be given to microcontroller from the switches and as per that input the Microcontroller can show symbols of LEFT-RIGHT on LCD and finally controlling the 12v bulbs used in indicators through TO-220 transistor.

The Motorbike has the switch like (left--OFF--right)

Im asking about whether im on the right track

You could probably just use a simple voltage divider from the switch to drop the inputs down below 12V.

I think he wants to switch the signal lights between "Left", "Off" and "Right" with the LCD displaying the appropriate direction (ie "LEFT" or "RIGHT")

Your plan sounds good. It shouldn't be a problem.

I think I got it.

He wants to make turn signals and have an indicator on his LCD that tells him when the turn signal is activated. Just like on the dash of your car.

Thanks John S and Delta_G you both got me Correct i have the answer from John what you say Delta_G about my way of connection?

Thanks James for Voltage Divider way i think with this way i will not need to modify the current controlled by the switch it will remain 12v to provide to the indicator bulbs and voltage divider will provide about 5v to analog inputs.

I too suggest leaving the indicator switching 12v to the indicator lamps and using voltage dividers. However you don't need to use analog inputs, you could use digital inputs. If you use a 100K resistor from the pin to the +12v output from the indicator switch and a 56K resistor from the pin to ground, then you will still get 3v on the digital input (enough to register a logic HIGH) even when the battery is as low as 8.4v. By choosing the resistors this high, the current flowing into the protection diode in the Arduino will be limited to a safe value even if you get large transients on the +12v supply.

Thanks dc42 will do the same