ky040 encoder test sketch on i2c lcd

hello have been playing around encoder , 20-04 i2c fed lcd trying both work there have read lot of old posts on subject small amount of learning have ( best way learn put together)
the problem cannot see encoder counts ok counter clockwise  clockwise shows 0-1-0 , on
 i think problem lies incrementing decrementing count ?? think, take please , enlighten me thanks

code: [select]


#include <liquidcrystal_i2c.h>

// lcd defaults
#define i2c_addr    0x27  // define i2c address pcf8574a is
#define backlight_pin 3
#define en_pin  2
#define rw_pin  1
#define rs_pin  0
#define d4_pin  4
#define d5_pin  5
#define d6_pin  6
#define d7_pin  7

liquidcrystal_i2c lcd(i2c_addr,en_pin,rw_pin,rs_pin,d4_pin,d5_pin,d6_pin,d7_pin);

const int pinclk = 2;                   // used generating interrupts using clk signal
const int pindt = 3;                    // used reading dt signal
const int pinsw = 4;                    // used push button switch
const int pinled = 13;

int sw;
int oldsw;

volatile boolean encchanged;
volatile long encposition = 0;
volatile boolean up;

void isr()  {                    // interrupt service routine executed when high low transition detected on clk
  volatile boolean clk = digitalread(pinclk);
  volatile boolean dt = digitalread(pindt);
  = ((!clk && dt) || (clk && !dt));
  if (!up)
    encposition++;
  else
    encposition--;
  if (encposition < 0) encposition = 0;
  encchanged = true;
  delay(10);
}


void setup()  {
  pinmode(pinclk, input);
  pinmode(pindt, input);
  pinmode(pinsw, input_pullup);
  pinmode(pinled, output);
  sw = high;
  oldsw = high;
  attachinterrupt(0, isr, falling);   // interrupt 0 connected pin 2 on arduino uno
 
  serial.begin(9600);
  serial.println("start");

 lcd.setbacklightpin(backlight_pin,positive);
  lcd.setbacklight(high);
  lcd.begin(20,4);      // cuzz have 20x4 display
  lcd.clear();           // rid of garbage might appear on startup
  lcd.print("ky040 encoder test ");
  lcd.setcursor(0,1);
  lcd.print("rotated");

}
void loop()  {
 
 
 
  sw = digitalread(pinsw);
  if ( sw == low && oldsw == high) {      // check if pushbutton pressed
    encposition = 0;              // if yes, reset counter zero
    serial.print("reset");
    encchanged = true;
  }
  oldsw = sw;

  if (encchanged)  {        // if rotation detected
    encchanged = false;          // not repeat if loop until new rotation detected
     serial.print("count = ");
     serial.println(encposition);
     analogwrite(pinled, encposition);
     lcd.setcursor(12,1);
     lcd.print(encposition);
   
  }
}



i don't know problem isr should never have delay(...) statement in it.

1)  delay(...) depends upon interrupts disabled while in isr.
2)  isr should execute possible.  delay(..) slows down isr , prevents executing possible.

ditto serial.print(...) , cousins.

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