converting car 12v to logic lvl 5v

Thread Starter

JK-FlipFlop

Joined Jul 5, 2010
111
Hi,

I am trying to connect my car's blinkers and breaks lights to my PIC uC for my application, therefore I need to convert the 12v to 5v logic lvl.

I bought some FET N-channel transistors to do that, and for some reason I cant make it work as it should.

2N7000: http://www.fairchildsemi.com/ds/2N/2N7000.pdf

Please, can you show me how to connect this right???
little schematic circuit will do the work.

Thank you.
 

Thread Starter

JK-FlipFlop

Joined Jul 5, 2010
111
So take it as voltage converting application, any voltage input to 5v logic lvl for uC.
Or I guess you didn't understood me, I want the uC to "know" when I use the breaks or turning on the blinkers.
It's not matter for what it used for, its pure electronics.

Please help, thank you!
 

strantor

Joined Oct 3, 2010
5,226
you could use a phototransistor or photoresistor to sense the light from the brakes/blinkers to avoid tampering with your car's electrical system
 

Thread Starter

JK-FlipFlop

Joined Jul 5, 2010
111
But it will be "mechanical" way to do it, forget what I have said about the car, Now I just want to convert 12v pulses to 5v logic for uC by simple transistor.
 

strantor

Joined Oct 3, 2010
5,226
But it will be "mechanical" way to do it, forget what I have said about the car, Now I just want to convert 12v pulses to 5v logic for uC by simple transistor.
cat's already out of the bag. can't put it back in.

this is as good a way as any; why do you not consider it? it may actually use less parts than the other methods
you could use a phototransistor or photoresistor or photodiode to sense the light from the brakes/blinkers to avoid tampering with your car's electrical system
 

Thread Starter

JK-FlipFlop

Joined Jul 5, 2010
111
Thank you for your creative way to do it, but I want it to be solved by transistor, and to learn what have I done wrong.

Please more help,

Thank you.
 

SgtWookie

Joined Jul 17, 2007
22,210
Just out of curiosity, how did you try to connect up the 2N7000 MOSFETs?

And what is it that you are wanting to accomplish with the PIC?
 

Thread Starter

JK-FlipFlop

Joined Jul 5, 2010
111
Basically I tried connecting it by many ways, but it should be connected as a "switch" to the PIC.

And Iam sure you know how to do that...

Can you help me Please?
 
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