capacitor meter

Using Arduino Displays
#1

Hi,

I’m trying too run my capacitormeter on the arduino nano with a I2C-LCD display…
The only problem is that only the top row of the LCD light up, if i put the contrast on full… And all the pixels are on…
Do you see any problem in the code?

Also did a address test…

I2C Scanner
Scanning…
I2C device found at address 0x27 !
done

// Digitale capaciteitsmeter
// (C) 2013 Hackerstore
#include <Wire.h>
#include "LCDI2C4Bit.h"

#define ANALOGE_PEN A3  // Analoge pen tussen R1/R2 en de condensator
#define R1_PEN      2   // Pen aan R1 (22k-weerstand)
#define R2_PEN      3   // Pen aan R2 (1,5k-weerstand)

LCDI2C4Bit lcd(0x27,2,16); // LCD-Display met I2C-interface

void setup() {
 pinMode(R1_PEN, OUTPUT);
 digitalWrite(R1_PEN, LOW);  
 
 lcd.begin();
 lcd.backLight(true);
 lcd.clear();  
}

void loop() {
 Ontlaad();
 
 // Meet de condensator
 digitalWrite(R1_PEN, HIGH); // Laadt de condensator (indien er 1 is aangesloten tenminste) op
 long tStart = millis();
 while(analogRead(ANALOGE_PEN)<647);
 long nDuur = abs(millis()-tStart);
 
 // Bereken de waarde van de gemeten condensator
 float fMicroFarad = ((float)nDuur/22000.0) * 1000;   

 // Toon de waarde op het LCD
 if(fMicroFarad >= 1.0){
  static char mf[3];
  mf[0]=0xe4; // Dit is het micro-symbool (Griekse letter mu), voor microFarad
  mf[1]='F'; 
  mf[2]=0;
  lcd.clear();
  lcd.print("    ");
  lcd.print(fMicroFarad); 
  lcd.print(" ");
  lcd.print(mf);
  delay(200);
 }
 else {
  // Toon waarde in nF
  lcd.clear();
  lcd.print("    ");
  lcd.print(fMicroFarad*1e3); 
  lcd.print(" ");
  lcd.print("nF");
  delay(500); // Iets langere delay dan bij uF! 
 } 
}

void Ontlaad() { // Ontlaad de condensator zodat hij gereed is voor een volgende meting 
 digitalWrite(R1_PEN, LOW);            
 pinMode(R2_PEN, OUTPUT);           
 digitalWrite(R2_PEN, LOW);         
 while(analogRead(ANALOGE_PEN)>0);  
 pinMode(R2_PEN, INPUT);     
}
#2

I think it's cool that you're connecting you're capcitor
meter but if you're post is get help with your
display, the only schematic that is relevant right
now is one showing the connections to your
display. I'm not seeing any reference to your
display connections in the definitions. Also,
I'm not sure that is the best library to use.

#3