Ultra Flat Screen

1void setup() {
2  // put your setup code here, to run once:
3  DDRB  = DDRB | B00111111;
4  DDRD = DDRD | B11111100; //set digital ports as output
5
6  PORTB = PORTB | B00111111;
7  PORTD = PORTD | B11111100; //put all small LED's  to sleep
8
9
10  pinMode(A1, OUTPUT);   
11  digitalWrite(A1,1);  //set A1  to feed position measurement  
12  pinMode(A2, OUTPUT);   
13  digitalWrite(A2,1);  //switch on LED distance measurement
14
15  pinMode(A0, INPUT);  //set A0 to  monitor phototransistor
16  
17  Serial.begin(9600); //just in case we need this  for trouble shooting
18  delay(1000);
19
20}
21
22unsigned int nf    [8] =  {256*B00000000+B00000000,
23                          256*B00111110+B10000100,
24                          256*B00100000+B11000100,
25                          256*B00100000+B10100100,
26                          256*B00111100+B10010100,
27                          256*B00100000+B10001100,
28                          256*B00100000+B10000100,
29                          256*B00000000+B00000000
30                         };
31                          
32unsigned int heart  [8] = {256*B00000000+B00000000,
33                           256*B00001110+B11100000,
34                           256*B00011111+B11110000,
35                           256*B00111111+B11111000,
36                           256*B00001111+B11100000,
37                           256*B00000011+B10000000,
38                           256*B00000001+B00000000,
39                           256*B00000000+B00000000
40                           };
41
42unsigned int v      [8] = {256*B00000000+B00000000,
43                           256*B00100000+B00000100,
44                           256*B00010000+B00001000,
45                           256*B00001000+B00010000,
46                           256*B00000100+B00100000,
47                           256*B00000010+B01000000,
48                           256*B00000001+B10000000,
49                           256*B00000000+B00000000
50                           };
51
52
53
54
55
56void  loop() {
57  byte curPos = measPos(); //read position
58  toScreen(nf[curPos]);  //send message as function of current position
59  //delay(100);
60}
61
62
63//write  message to screen
64void toScreen(int msg) {
65  PORTB = ~highByte(msg); //LEDs  are common anode!!!
66  PORTD = ~lowByte(msg);
67}
68
69//measure position
70byte  measPos() {
71
72  unsigned int E = analogRead(A0);  //read phototransistor
73  
74  //select valid range
75  const unsigned int Emax = 800;
76  const unsigned  int Emin = 600;
77 // Serial.println(E);
78  if (E <= Emin) return 0; 
79  if  (E >= Emax) return 0;
80
81  //linearize valid range
82  const unsigned int maxInt  = 65535; //maximum value in two byte integer (2^16-1)
83  const unsigned int recEmax  = maxInt/Emax;
84  const unsigned int recEmin = maxInt/Emin;
85  const byte numPos  = 8;
86  unsigned int recE = maxInt/E;
87  byte measPos = (recE - recEmax) * numPos  / (recEmin - recEmax); 
88  //measPos = (1.0/E-1.0/Emax)*numPos/(1.0/Emin-1.0/Emax);  
89
90  //Serial.println(measPos);
91
92  return numPos-measPos-1;
93}
94
95