[SOLVED] 4-20 ma sensor reading

hi all, i'm new in arduino world, , must read value 2 wire sensor , display on lcd http://tronixstuff.wordpress.com/2011/03/12/the-dfrobot-lcd4884-lcd-shield/

actually thing arduino read 1023, code this:

quote

#include <lcd4884.h>

void setup(){
lcd.lcd_init();
pinmode(7, output);
{serial.begin(9600);
pinmode(a5, input);
analogreference(default);
lcd.lcd_write_string(0,1,"accensione...", menu_normal);}
delay(500);}

int val = 0;
int analogpin = 5;

char valadc[4] = "0";
char pres[4] = "0";

void loop()
{
 val = analogread(analogpin);
 dtostrf(val, 4, 0, valadc);
 serial.println(val);
 lcd.lcd_clear();
 lcd.lcd_write_string(0,1, "lettura adc:", menu_normal);
 lcd.lcd_write_string(0,2, valadc, menu_normal);
 delay (100);
}

and analog input taken on 250ohm resistor in series sensor, project work 12v...

thanks all!

post diagram of connected - way definitive answer, rather guesses problem. 
most (industrial standard) 4-20 units require @ least 18 volts (preferably 24) drive them properly. 
even if problem software issue beneficial see circuit hook-up diagram.

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