Subversion Repositories Code-Repo

Rev

Rev 279 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
279 Kevin 1 
#include <xc.h>
2 
#include "defines.h"
3 
#include "NEOPIXEL.h"
4 
 
5 
static NEOPIXEL_DATA* neopixel_data_ptr;
6 
 
7 
void NeoPixel_Init(NEOPIXEL_DATA *data) {
8 
    neopixel_data_ptr = data;
9 
 
10 
    // Clear buffer
11 
    for (char i = 0; i < NEOPIXEL_LENGTH * 3; i++) {
12 
        neopixel_data_ptr->values[i] = 0x0;
13 
    }
14 
 
15 
    // Output pin initially blocked
16 
    NEOPIXEL_TRIS = 1;
17 
 
18 
    /* Initialize PWM module */
19 
    PR2 = 0x09; // 1.25us @ 32MHz
20 
    CCP1CONbits.P1M = 0b00;     // Single output, P1A modulated only
21 
    CCP1CONbits.CCP1M = 0b1100; // PWM mode, P1A active-high, P1B active-high
22 
 
23 
    // Idle the output till width is specified
24 
    CCPR1L = 0x00;
25 
    CCP1CONbits.DC1B = 0b00;
26 
 
27 
    /* Initialize Timer 2 */
28 
    PIR1bits.TMR2IF = 0;        // Clear the interrupt flag for Timer 2
29 
    T2CONbits.T2CKPS = 0b00;    // Set a prescaler of 1:1
30 
    T2CONbits.TMR2ON = 1;       // Enable the timer
31 
 
32 
    // Wait for the timer to overflow before enabling output
33 
    while (!PIR1bits.TMR2IF);
34 
    NEOPIXEL_TRIS = 0;
35 
}
36 
 
37 
void NeoPixel_Set(char index, char R, char G, char B) {
38 
    if (index >= NEOPIXEL_LENGTH) return;
39 
 
40 
    neopixel_data_ptr->values[(index * 3) + 0] = G;
41 
    neopixel_data_ptr->values[(index * 3) + 1] = R;
42 
    neopixel_data_ptr->values[(index * 3) + 2] = B;
43 
}
44 
 
45 
void NeoPixel_Write_All(void) {
46 
    for (char i = 0; i < NEOPIXEL_LENGTH * 3; i++) {
47 
        NeoPixel_Write_One(neopixel_data_ptr->values[i]);
48 
    }
49 
    // Delay for 50us to latch data
50 
    __delay_us(50);
51 
}
52 
 
53 
void NeoPixel_Write_One(char value) {
54 
    // Enable timer and wait for it to overflow
55 
    T2CONbits.TMR2ON = 1;
56 
    while (!PIR1bits.TMR2IF);
57 
 
58 
    // Set pulse width for bit 7
59 
    if (value & 0x80) {
60 
        CCPR1L = NEOPIXEL_LOGIC_1; // ~800ns high, ~450ns low (logic 1)
61 
    } else {
62 
        CCPR1L = NEOPIXEL_LOGIC_0; // ~400ns high, ~850ns low (logic 0)
63 
    }
64 
    while (!PIR1bits.TMR2IF);
65 
 
66 
    // Set pulse width for bit 6
67 
    if (value & 0x40) {
68 
        CCPR1L = NEOPIXEL_LOGIC_1; // ~800ns high, ~450ns low (logic 1)
69 
    } else {
70 
        CCPR1L = NEOPIXEL_LOGIC_0; // ~400ns high, ~850ns low (logic 0)
71 
    }
72 
    while (!PIR1bits.TMR2IF);
73 
 
74 
    // Set pulse width for bit 5
75 
    if (value & 0x20) {
76 
        CCPR1L = NEOPIXEL_LOGIC_1; // ~800ns high, ~450ns low (logic 1)
77 
    } else {
78 
        CCPR1L = NEOPIXEL_LOGIC_0; // ~400ns high, ~850ns low (logic 0)
79 
    }
80 
    while (!PIR1bits.TMR2IF);
81 
 
82 
    // Set pulse width for bit 4
83 
    if (value & 0x10) {
84 
        CCPR1L = NEOPIXEL_LOGIC_1; // ~800ns high, ~450ns low (logic 1)
85 
    } else {
86 
        CCPR1L = NEOPIXEL_LOGIC_0; // ~400ns high, ~850ns low (logic 0)
87 
    }
88 
    while (!PIR1bits.TMR2IF);
89 
 
90 
    // Set pulse width for bit 3
91 
    if (value & 0x08) {
92 
        CCPR1L = NEOPIXEL_LOGIC_1; // ~800ns high, ~450ns low (logic 1)
93 
    } else {
94 
        CCPR1L = NEOPIXEL_LOGIC_0; // ~400ns high, ~850ns low (logic 0)
95 
    }
96 
    while (!PIR1bits.TMR2IF);
97 
 
98 
    // Set pulse width for bit 2
99 
    if (value & 0x04) {
100 
        CCPR1L = NEOPIXEL_LOGIC_1; // ~800ns high, ~450ns low (logic 1)
101 
    } else {
102 
        CCPR1L = NEOPIXEL_LOGIC_0; // ~400ns high, ~850ns low (logic 0)
103 
    }
104 
    while (!PIR1bits.TMR2IF);
105 
 
106 
    // Set pulse width for bit 1
107 
    if (value & 0x02) {
108 
        CCPR1L = NEOPIXEL_LOGIC_1; // ~800ns high, ~450ns low (logic 1)
109 
    } else {
110 
        CCPR1L = NEOPIXEL_LOGIC_0; // ~400ns high, ~850ns low (logic 0)
111 
    }
112 
    while (!PIR1bits.TMR2IF);
113 
 
114 
    // Set pulse width for bit 0
115 
    if (value & 0x01) {
116 
        CCPR1L = NEOPIXEL_LOGIC_1; // ~800ns high, ~450ns low (logic 1)
117 
    } else {
118 
        CCPR1L = NEOPIXEL_LOGIC_0; // ~400ns high, ~850ns low (logic 0)
119 
    }
120 
 
121 
    // Idle line low
122 
    while (!PIR1bits.TMR2IF);
123 
    asm("NOP");
124 
    asm("NOP");
125 
    asm("NOP");
126 
    asm("NOP");
127 
    asm("NOP");
128 
    CCPR1L = 0b00000000;
129 
 
130 
    // Disable and reset timer
131 
    while (!PIR1bits.TMR2IF);
132 
    asm("NOP");
133 
    asm("NOP");
134 
    T2CONbits.TMR2ON = 0;
135 
    TMR2 = 0x0;
136 
}