/*
   ATtiny85 with 74HC595 (shift register)

   This sketch was written by SparkFun Electronics
   with lots of help from the Arduino community
   and modified by the Wokwi community.
   This code is completely free for any use.

   See the shift register datasheet for details:
   http://www.sparkfun.com/datasheets/IC/SN74HC595.pdf

   Visit http://www.arduino.cc to learn about the Arduino.
   Visit http://wokwi.com to learn about the Wokwi Simulator.
*/

#include "TinyDebug.h"

// The 74HC595 uses a type of serial connection called SPI
// (Serial Peripheral Interface) that requires three pins:

#define DATA_PIN  PB0 // Pin connected to DS of 74HC595
#define CLOCK_PIN PB2 // Pin connected to SHCP of 74HC595
#define LATCH_PIN PB1 // Pin connected to STCP of 74HC595

// Global variable for the data we're sending to the shift register
uint8_t data = 0;
uint8_t shift = 0;
uint8_t lastShift = 0;
uint16_t delayTime = 0;
uint16_t lastDelay = 0;

void setup() {
  Debug.begin();
  delay(100);
  // Set pins to potentiometers input
  pinMode(A2, INPUT);
  pinMode(A3, INPUT);
  // Set pins to 74HC595 output
  pinMode(DATA_PIN, OUTPUT);
  pinMode(CLOCK_PIN, OUTPUT);
  pinMode(LATCH_PIN, OUTPUT);
}

void loop() {
  // Change to try the different functions below
  shift = map(analogRead(A2), 0, 1023, 1, 6);

  // Make this smaller for faster switching
  delayTime = map(analogRead(A3), 0, 1023, 25, 125);

  if (shift != lastShift) {
    lastShift = shift;
    Debug.print("Function: ");
    Debug.println(shift);
  }

  if (delayTime != lastDelay) {
    lastDelay = delayTime;
    Debug.print("Delay(ms) ");
    Debug.println(delayTime);
  }

  switch (shift) {
    case 1: oneAfterAnother(); // All on, all off
      break;
    case 2: oneOnAtATime();    // Scroll down the line
      break;
    case 3: pingPong();        // Like above, but back and forth
      break;
    case 4: randomLED();       // Blink random LEDs
      break;
    case 5: marquee();
      break;
    case 6: binaryCount();     // Bit patterns from 0 to 255
      break;
  }
}

void shiftWrite(int desiredPin, boolean desiredState) {
  // This function lets you make the shift register outputs
  // HIGH or LOW in exactly the same way that you use digitalWrite()
  bitWrite(data, desiredPin, desiredState); // Change desired bit to 0 or 1 in "data"

  // Now we'll actually send that data to the shift register.
  // The shiftOut() function does all the hard work of
  // manipulating the data and clock pins to move the data
  // into the shift register:
  shiftOut(DATA_PIN, CLOCK_PIN, MSBFIRST, data); // Send "data" to the shift register

  // Toggle the latchPin to make "data" appear at the outputs
  digitalWrite(LATCH_PIN, HIGH);
  digitalWrite(LATCH_PIN, LOW);
}

void oneAfterAnother() {
  // This function will turn on all the LEDs, one-by-one,
  // and then turn them off all off, one-by-one
  int index;

  // Turn all the LEDs on
  for (index = 0; index <= 7; index++) {
    shiftWrite(index, HIGH);
    delay(delayTime);
  }

  // Turn all the LEDs off
  for (index = 7; index >= 0; index--) {
    shiftWrite(index, LOW);
    delay(delayTime);
  }
}

void oneOnAtATime() {
  // This function will turn the LEDs on and off, one-by-one
  int index;

  // Step through the LEDs, from 0 to 7
  for (index = 0; index <= 7; index++) {
    shiftWrite(index, HIGH); // Turn LED on
    delay(delayTime);        // Pause to slow down the sequence
    shiftWrite(index, LOW);  // Turn LED off
  }
}

void pingPong() {
  // This function turns on the LEDs, one at a time, in both directions
  int index;

  // Step through the LEDs, from 0 to 7
  for (index = 0; index <= 7; index++) {
    shiftWrite(index, HIGH); // Turn LED on
    delay(delayTime);        // Pause to slow down the sequence
    shiftWrite(index, LOW);  // Turn LED off
  }

  // Step through the LEDs, from 7 to 0
  for (index = 7; index >= 0; index--) {
    shiftWrite(index, HIGH); // Turn LED on
    delay(delayTime);        // Pause to slow down the sequence
    shiftWrite(index, LOW);  // Turn LED off
  }
}

void randomLED() {
  // This function will randomly turn on and off LEDs
  int index;

  index = random(8);         // Pick a random number between 0 and 7

  shiftWrite(index, HIGH);   // Turn LED on
  delay(delayTime);          // Pause to slow down the sequence
  shiftWrite(index, LOW);    // Turn LED off
}

void marquee() {
  // This function will mimic "chase lights" like those around signs
  int index;

  // Step through the first four LEDs
  // (We'll light up one in the lower 4 and one in the upper 4)
  for (index = 0; index <= 3; index++) {
    shiftWrite(index, HIGH);     // Turn a LED on
    shiftWrite(index + 4, HIGH); // Skip four, and turn that LED on
    delay(delayTime);            // Pause to slow down the sequence
    shiftWrite(index, LOW);      // Turn both LEDs off
    shiftWrite(index + 4, LOW);
  }
}

void binaryCount() {
  // This function creates a visual representation of the
  // on/off pattern of bits in a byte

  // Send the data byte to the shift register:
  shiftOut(DATA_PIN, CLOCK_PIN, MSBFIRST, data);

  // Toggle the latch pin to make the data appear at the outputs:
  digitalWrite(LATCH_PIN, HIGH);
  digitalWrite(LATCH_PIN, LOW);

  // Add one to data, and repeat!
  // (Because a byte type can only store numbers from 0 to 255,
  // if we add more than that, it will "roll around" back to 0
  // and start over)
  data++;

  // Delay so you can see what's going on:
  delay(delayTime);
}