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hello again friends ,
I want make a fast rpm meter ,you understand me ofcourse ,

now I just trying on my car ,its my first dynamic test for this.
Im connect pic`s (portc.2) to car ecu rpm out ....

hi people ,

if I use
count PORTB.0,100,rpm
the result is poor quality ,

if I use
count PORTB.0,1000,rpm
the result is very slowly ,

@skimask ,
I`ll take this picture only for you :)

Schmit trigger ;
Because I`m work on the table at home ,not on car ,
and use a 555 for signal not car enjector`s signal .
Im sure cars...

This code is better work ,

'DEVICE 16F84A
DEFINE OSC 10

DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 3
DEFINE LCD_EREG PORTB

@Skimask ,
yess its work ,thank your interesting .
Its not bad ,so close result with duty cycle meter.
I can use it on my car .

Some problem I have ,

1-why I see on the lcd "35" %100 duty...

whats wrong ?


'DEVICE 16F84A
DEFINE OSC 10

DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 3

Here simple "pulsin" code ,
yes its not finish .Only run for test .

'DEVICE 16F84A
DEFINE OSC 10

DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 3

PWM generator ,this simple circuit come with duty cycle meter .
Its use for test.
http://img460.imageshack.us/img460/8074/pwm1ql7.jpg


PWM generator shema ,simple 555 pwm generator ....

@skimask you are right ,
I work on proteus before ,

Now Im just build circuit on breadboard.
And Im take some shoot.

This is "duty cycle meter" working circuit ,I say before ..
Its working...

I can try but fail ,
Maybe Im not expert ,I dont .

Hi again and thank your answers ,

Dear mister_e ,

I give to a circuit example in my first message (jaycar kit) use a 16F84A ,
This kit is working good and without any problem .
What is your...

Hello friends ,

I`m trying measure my cars injectors duty cycle .
Have any body experince about this ?

For example ,
injectors running pwm cycle ,
if injectors full open ,I must see %100...

Veijavi ,
Im interesting your project ,

also I think you dont need rpm data ,
if you know injectors duty cycle, calculate per hour fuel consumption .
for example ,if your injectors 200 cc/min...