/*
bicycle_keyboard
*/#include "Keyboard.h"
const int hall_effect_threshold = 1      // threshold for hall effect sensor.
const int turn_threshold = 35;           // threshold for detecting a left/right movement. 
const int drive_decay_const = 100;       // drive_decay speed of car (larger => slower decreasing / faster car)
const int turn_decay_const = 0.75;       // multiplier for intensity of turn. higher value => sharper turns. 
const char button_1_val = ' ';           // value for button 1
const char button_2_val = 'n';           // value for button 2
const long interval = 200;               // interval for allowing not allowing turns.
const int button_1 = 2;                  // button_1 pin 
const int button_2 = 3;                  // button_2 pin
int pot_center = 500;                    // center point for potentiometer. this value is being reset in setup.
int prev_hallSensorValue = 0;            // initial value for sensor
const int delay_time = 1;                // delay between reads
int drive_decay = 0;                     // initial drive_decay value
unsigned long previousMillis = 0;        // initial value
bool allow_turn = true;                  // allow turn is a boolean to only allow turns every passing interval 
int turn_amount = 0;                     // initial value

void setup() {
  Serial.begin(9600);
  Keyboard.begin();
  pinMode(button_1, INPUT);
  pinMode(button_2, INPUT);
  pot_center = analogRead(A1);
}

void loop() {
  unsigned long currentMillis = millis();
  int hallSensorValue = analogRead(A0);
  int pot = analogRead(A1);//  Serial.println(hallSensorValue);
//  Serial.println(pot);  delay(delay_time);        // delay in between reads for stability  // DRIVE:
  if (abs(hallSensorValue- prev_hallSensorValue) >1){
    prev_hallSensorValue = hallSensorValue;
    Keyboard.press(KEY_UP_ARROW);
    drive_decay = drive_decay_const;
  }
  else{
    if (drive_decay <= 0){
        Keyboard.release(KEY_UP_ARROW);
        }
    else{
      drive_decay -=1;
      }
    }if (allow_turn==true){
//TURN RIGHT
  if (pot < pot_center - turn_threshold) {
    Keyboard.press(KEY_RIGHT_ARROW);
    } 
// TURN LEFT
  if (pot > pot_center + turn_threshold){
    Keyboard.press(KEY_LEFT_ARROW);
  }}
    if (currentMillis - previousMillis >= interval) { // interval has passed
    previousMillis = currentMillis;
    turn_amount = abs(pot-pot_center);    // switch allow turn state:
    if (allow_turn == true) {
      if (turn_amount > turn_threshold){
          delay(turn_amount); //keep button pressed longer the more aggressive the turn.
        }
      allow_turn = false;
    } else {
      allow_turn = true;
      }
     // release the turn keys:
      Keyboard.release(KEY_RIGHT_ARROW);
      Keyboard.release(KEY_LEFT_ARROW);
    }  //check buttons
  if (digitalRead(button_1) == HIGH){
    Keyboard.press(button_1_val);
    }
   else{
     Keyboard.release(button_1_val);
    }  if (digitalRead(button_2) == HIGH){
    Keyboard.press(button_2_val);
    }
   else{
     Keyboard.release(button_2_val);
    }
}