2 * light weight WS2812 lib V2.0b
4 * Controls WS2811/WS2812/WS2812B RGB-LEDs
5 * Author: Tim (cpldcpu@gmail.com)
7 * Jan 18th, 2014 v2.0b Initial Version
8 * Nov 29th, 2015 v2.3 Added SK6812RGBW support
10 * License: GNU GPL v2 (see License.txt)
13 #include "light_ws2812.h"
14 #include <avr/interrupt.h>
16 #include <util/delay.h>
19 // Setleds for standard RGB
20 void inline ws2812_setleds(struct cRGB *ledarray, uint16_t leds)
22 ws2812_setleds_pin(ledarray,leds, _BV(ws2812_pin));
25 void inline ws2812_setleds_pin(struct cRGB *ledarray, uint16_t leds, uint8_t pinmask)
27 ws2812_DDRREG |= pinmask; // Enable DDR
28 ws2812_sendarray_mask((uint8_t*)ledarray,leds+leds+leds,pinmask);
32 // Setleds for SK6812RGBW
33 void inline ws2812_setleds_rgbw(struct cRGBW *ledarray, uint16_t leds)
35 ws2812_DDRREG |= _BV(ws2812_pin); // Enable DDR
36 ws2812_sendarray_mask((uint8_t*)ledarray,leds<<2,_BV(ws2812_pin));
40 void ws2812_sendarray(uint8_t *data,uint16_t datlen)
42 ws2812_sendarray_mask(data,datlen,_BV(ws2812_pin));
46 This routine writes an array of bytes with RGB values to the Dataout pin
47 using the fast 800kHz clockless WS2811/2812 protocol.
51 #define w_zeropulse 350
52 #define w_onepulse 900
53 #define w_totalperiod 1250
55 // Fixed cycles used by the inner loop
58 #define w_fixedtotal 8
60 // Insert NOPs to match the timing, if possible
61 #define w_zerocycles (((F_CPU/1000)*w_zeropulse )/1000000)
62 #define w_onecycles (((F_CPU/1000)*w_onepulse +500000)/1000000)
63 #define w_totalcycles (((F_CPU/1000)*w_totalperiod +500000)/1000000)
65 // w1 - nops between rising edge and falling edge - low
66 #define w1 (w_zerocycles-w_fixedlow)
67 // w2 nops between fe low and fe high
68 #define w2 (w_onecycles-w_fixedhigh-w1)
69 // w3 nops to complete loop
70 #define w3 (w_totalcycles-w_fixedtotal-w1-w2)
78 // The only critical timing parameter is the minimum pulse length of the "0"
79 // Warn or throw error if this timing can not be met with current F_CPU settings.
80 #define w_lowtime ((w1_nops+w_fixedlow)*1000000)/(F_CPU/1000)
82 #error "Light_ws2812: Sorry, the clock speed is too low. Did you set F_CPU correctly?"
84 #warning "Light_ws2812: The timing is critical and may only work on WS2812B, not on WS2812(S)."
85 #warning "Please consider a higher clockspeed, if possible"
100 #define w_nop1 "nop \n\t"
101 #define w_nop2 "rjmp .+0 \n\t"
102 #define w_nop4 w_nop2 w_nop2
103 #define w_nop8 w_nop4 w_nop4
104 #define w_nop16 w_nop8 w_nop8
106 void inline ws2812_sendarray_mask(uint8_t *data,uint16_t datlen,uint8_t maskhi)
108 uint8_t curbyte,ctr,masklo;
111 masklo =~maskhi&ws2812_PORTREG;
112 maskhi |= ws2812_PORTREG;
122 " out %2,%3 \n\t" // '1' [01] '0' [01] - re
138 " sbrs %1,7 \n\t" // '1' [03] '0' [02]
139 " out %2,%4 \n\t" // '1' [--] '0' [03] - fe-low
140 " lsl %1 \n\t" // '1' [04] '0' [04]
156 " out %2,%4 \n\t" // '1' [+1] '0' [+1] - fe-high
173 " dec %0 \n\t" // '1' [+2] '0' [+2]
174 " brne loop%=\n\t" // '1' [+3] '0' [+4]
176 : "r" (curbyte), "I" (_SFR_IO_ADDR(ws2812_PORTREG)), "r" (maskhi), "r" (masklo)