Pixie Chroma
Documentation for the easiest 5x7 LED displays for Arduino!
pixie_utility.h
Go to the documentation of this file.
1 
9 #ifndef pixie_utility_h
10 #define pixie_utility_h
11 
12 // Extra utilities for PixieChroma code, such as the gamma LUT
13 
15 void (*anim_func)(PixieChroma* _p, float delta);
16 
18 const int8_t xy_template[77] PROGMEM = {
19  -2, -2, -2, -2, -2, -2, -2,
20  -2, -2, -2, -2, -2, -2, -2,
21  -2, -1, -1, -1, -1, -1, -2,
22  -2, -1, -1, -1, -1, -1, -2,
23  -2, -1, -1, -1, -1, -1, -2,
24  -2, -1, -1, -1, -1, -1, -2,
25  -2, -1, -1, -1, -1, -1, -2,
26  -2, -1, -1, -1, -1, -1, -2,
27  -2, -1, -1, -1, -1, -1, -2,
28  -2, -2, -2, -2, -2, -2, -2,
29  -2, -2, -2, -2, -2, -2, -2
30 };
31 
33 const uint8_t gamma8[] = {
34  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
35  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1,
36  1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2,
37  2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5,
38  5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10,
39  10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 14, 14, 15, 15, 16, 16,
40  17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 24, 24, 25,
41  25, 26, 27, 27, 28, 29, 29, 30, 31, 32, 32, 33, 34, 35, 35, 36,
42  37, 38, 39, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 50,
43  51, 52, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 67, 68,
44  69, 70, 72, 73, 74, 75, 77, 78, 79, 81, 82, 83, 85, 86, 87, 89,
45  90, 92, 93, 95, 96, 98, 99, 101,102,104,105,107,109,110,112,114,
46  115,117,119,120,122,124,126,127,129,131,133,135,137,138,140,142,
47  144,146,148,150,152,154,156,158,160,162,164,167,169,171,173,175,
48  177,180,182,184,186,189,191,193,196,198,200,203,205,208,210,213,
49  215,218,220,223,225,228,231,233,236,239,241,244,247,249,252,255
50 };
51 
60 char* dtoa(double input, char* buffer, int precision) {
61  int32_t whole_part = (int32_t) input;
62 
63  // Deposit the whole part of the number.
64  itoa( whole_part, buffer, 10 );
65 
66  // Now work on the faction if we need one.
67  if( precision > 0 ) {
68 
69  // We do, so locate the end of the string and insert
70  // a decimal point.
71  char* end_of_string = buffer;
72  while( *end_of_string != '\0' ){
73  end_of_string++;
74  }
75  *end_of_string++ = '.';
76 
77  // Now work on the fraction, being sure to turn any negative
78  // values positive.
79  if (input < 0) {
80  input *= -1;
81  whole_part *= -1;
82  }
83 
84  double fraction = input - whole_part;
85  while (precision > 0) {
86  // Multiply by ten and pull out the digit.
87  fraction *= 10;
88  whole_part = (int32_t) fraction;
89  *end_of_string++ = '0' + whole_part;
90 
91  // Update the fraction and move on to the
92  // next digit.
93  fraction -= whole_part;
94  precision--;
95  }
96 
97  // Terminate the string.
98  *end_of_string = '\0';
99  }
100 
101  return buffer;
102 }
103 
104 #endif
This is the software documentation for using Pixie Chroma functions on Arduino! For full example usag...
char * dtoa(double input, char *buffer, int precision)
Homebrew C function to convert double precision floats to char*. (Arduino Forum link)
Definition: pixie_utility.h:60
const uint8_t gamma8[]
Used as a fast lookup table for gamma correction.
Definition: pixie_utility.h:33
void(* anim_func)(PixieChroma *_p, float delta)
Used to store the pointer to any preset/custom animation functions the library needs to call during s...
Definition: pixie_utility.h:15
const int8_t xy_template[77] PROGMEM
Used as a template by calc_xy() to build the XY coordinate map for accessing 1D LEDS in a 2D context.
Definition: pixie_utility.h:18