Notes for Arduino LCD Keypad Shield

KeypadShield.c

// Notes for Arduino LCD Keypad Shield
// Create custom character: https://omerk.github.io/lcdchargen/
// String reference: https://www.arduino.cc/en/Reference/StringObject
// LCD reference: https://www.arduino.cc/en/Reference/LiquidCrystal
// Stream reference: http://playground.arduino.cc/Main/StreamingOutput

#define _BYTE(a)    _BYTE_CODE(a)
#define _HEX(a)     _BASED(a, HEX)
#define _DEC(a)     _BASED(a, DEC)
#define _OCT(a)     _BASED(a, OCT)
#define _BIN(a)     _BASED(a, BIN)
template<class T> inline Print &operator <<(Print &stream, T arg) { stream.print(arg); return stream; } struct _BASED { long val; int base; _BASED(long v, int b): val(v), base(b) {}}; struct _BYTE_CODE { byte val; _BYTE_CODE(byte v) : val(v) {} }; inline Print &operator <<(Print &obj, const _BYTE_CODE &arg) { obj.write(arg.val); return obj; }  inline Print &operator <<(Print &obj, const _BASED &arg) { obj.print(arg.val, arg.base); return obj; } struct _FLOAT { float val; int digits; _FLOAT(double v, int d): val(v), digits(d) {}}; inline Print &operator <<(Print &obj, const _FLOAT &arg) { obj.print(arg.val, arg.digits); return obj; } enum _EndLineCode { endl }; inline Print &operator <<(Print &obj, _EndLineCode arg) { obj.println(); return obj; }

#include <LiquidCrystal.h>
#define TIMEOUT 10

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

byte smiley[8] = {
  B00000,
  B10001,
  B00000,
  B00000,
  B10001,
  B01110,
  B00000,
};

typedef struct {
  int number;
} Object;

void setup() {
  // Initialize Serial
  Serial.begin(9600);
  Serial.setTimeout(TIMEOUT);

  // Initialize LCD and special characters
  lcd.createChar(0, smiley);
  lcd.begin(16, 2);
  lcd.write((byte)0);

  // Generate completely random
  randomSeed(analogRead(1));

  // Split string
  String t = "a b c d e";
  String splited[5];
  int len;
  splitString(splited, &len, t, " ");
  for (int i = 0; i < len; i++) {
    lcd.write(String(i+1).c_str());
    lcd.write(splited[i].c_str());
  }
}

void loop() {
  if (Serial.available() > 0) {
      
  }
}

char readKey() {
  short tolerance = 5;
  short value = analogRead(0);
  short values[] = {639, 408, 255, 99, 0};
  char out[]  = {'s', 'l', 'd', 'u', 'r'};
  for (int i = 0; i < 5; i++) {
    if (values[i] - tolerance < value && values[i] + tolerance > value) {
      return out[i];
    }
  }
  
  return '-';
}

String getRandomString(int n) {
    // Awful optimisation, but easy to scale
    char charset[] = "0123456789"
                     "abcdefghijklmnopqrstuvwxyz"
                     "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    String randomString = "";
    for (int i = 0; i < n; i++) {
      randomString += String(charset[random(0, strlen(charset))]);
    }
    return randomString;
}

void splitString(String *result, int *len, String source, String delimiter) {
  int i = 0;
  int endOfString;
  while ((endOfString = source.indexOf(delimiter)) > 0) {
    result[i++] = source.substring(0, endOfString);
    source.remove(0, endOfString + 1);
  }
  result[i++] = source;
  *len = i;
}