#include <stdio.h>
#include "pico/stdlib.h"
#include "hardware/pio.h"
#include "hardware/timer.h"
#include "hardware/pio.h"
#include "quadrature_encoder.pio.h"

//
// ---- quadrature encoder interface example
//
// the PIO program reads phase A/B of a quadrature encoder and increments or
// decrements an internal counter to keep the current absolute step count
// updated. At any point, the main code can query the current count by using
// the quadrature_encoder_*_count functions. The counter is kept in a full
// 32 bit register that just wraps around. Two's complement arithmetic means
// that it can be interpreted as a 32-bit signed or unsigned value, and it will
// work anyway.
//
// As an example, a two wheel robot being controlled at 100Hz, can use two
// state machines to read the two encoders and in the main control loop it can
// simply ask for the current encoder counts to get the absolute step count. It
// can also subtract the values from the last sample to check how many steps
// each wheel as done since the last sample period.
//
// One advantage of this approach is that it requires zero CPU time to keep the
// encoder count updated and because of that it supports very high step rates.
//
int new_value, delta, old_value = 0; 
const uint PIN_AB = 2;
const uint PIN_BA = 3;
  PIO pio = pio0; 
  const uint sm = 0;
    

    // Base pin to connect the A phase of the encoder.
    // The B phase must be connected to the next pin
   

 
        // note: thanks to two's complement arithmetic delta will always
        // be correct even when new_value wraps around MAXINT / MININT
  
 

void setup() {
  // put your setup code here, to run once:
  pinMode(PIN_AB, INPUT_PULLUP);
    pinMode(PIN_BA, INPUT_PULLUP);
Serial1.begin(115200);

    // we don't really need to keep the offset, as this program must be loaded
    // at offset 0
    pio_add_program(pio, &quadrature_encoder_program);
    quadrature_encoder_program_init(pio, 0, PIN_AB, 0);
}

void loop() {
  // put your main code here, to run repeatedly:
 new_value = quadrature_encoder_get_count(pio, sm)/4;
delta = new_value - old_value;
 old_value = new_value;
//Serial.print(position %8d, delta %6d\n", new_value, delta);
Serial1.print ("Position: ");
Serial1.println (new_value );
       
 delay(500);
}