/* * light weight WS2812 lib V2.0b * * Controls WS2811/WS2812/WS2812B RGB-LEDs * Author: Tim (cpldcpu@gmail.com) * * Jan 18th, 2014 v2.0b Initial Version * Nov 29th, 2015 v2.3 Added SK6812RGBW support * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "ws2812.h" #include <avr/interrupt.h> #include <avr/io.h> #include <util/delay.h> #define pinmask(pin) (_BV((pin)&0xF)) /* * Forward declare internal functions * * The functions take a byte-array and send to the data output as WS2812 bitstream. * The length is the number of bytes to send - three per LED. */ static inline void ws2812_sendarray_mask(uint8_t *data, uint16_t datlen, uint8_t masklo, uint8_t maskhi); void ws2812_setleds(LED_TYPE *ledarray, uint16_t number_of_leds) { DDRx_ADDRESS(RGB_DI_PIN) |= pinmask(RGB_DI_PIN); uint8_t masklo = ~(pinmask(RGB_DI_PIN)) & PORTx_ADDRESS(RGB_DI_PIN); uint8_t maskhi = pinmask(RGB_DI_PIN) | PORTx_ADDRESS(RGB_DI_PIN); ws2812_sendarray_mask((uint8_t *)ledarray, number_of_leds * sizeof(LED_TYPE), masklo, maskhi); _delay_us(WS2812_TRST_US); } /* This routine writes an array of bytes with RGB values to the Dataout pin using the fast 800kHz clockless WS2811/2812 protocol. */ // Timing in ns #define w_zeropulse 350 #define w_onepulse 900 #define w_totalperiod 1250 // Fixed cycles used by the inner loop #define w_fixedlow 2 #define w_fixedhigh 4 #define w_fixedtotal 8 // Insert NOPs to match the timing, if possible #define w_zerocycles (((F_CPU / 1000) * w_zeropulse) / 1000000) #define w_onecycles (((F_CPU / 1000) * w_onepulse + 500000) / 1000000) #define w_totalcycles (((F_CPU / 1000) * w_totalperiod + 500000) / 1000000) // w1 - nops between rising edge and falling edge - low #define w1 (w_zerocycles - w_fixedlow) // w2 nops between fe low and fe high #define w2 (w_onecycles - w_fixedhigh - w1) // w3 nops to complete loop #define w3 (w_totalcycles - w_fixedtotal - w1 - w2) #if w1 > 0 # define w1_nops w1 #else # define w1_nops 0 #endif // The only critical timing parameter is the minimum pulse length of the "0" // Warn or throw error if this timing can not be met with current F_CPU settings. #define w_lowtime ((w1_nops + w_fixedlow) * 1000000) / (F_CPU / 1000) #if w_lowtime > 550 # error "Light_ws2812: Sorry, the clock speed is too low. Did you set F_CPU correctly?" #elif w_lowtime > 450 # warning "Light_ws2812: The timing is critical and may only work on WS2812B, not on WS2812(S)." # warning "Please consider a higher clockspeed, if possible" #endif #if w2 > 0 # define w2_nops w2 #else # define w2_nops 0 #endif #if w3 > 0 # define w3_nops w3 #else # define w3_nops 0 #endif #define w_nop1 "nop \n\t" #define w_nop2 "rjmp .+0 \n\t" #define w_nop4 w_nop2 w_nop2 #define w_nop8 w_nop4 w_nop4 #define w_nop16 w_nop8 w_nop8 static inline void ws2812_sendarray_mask(uint8_t *data, uint16_t datlen, uint8_t masklo, uint8_t maskhi) { uint8_t curbyte, ctr, sreg_prev; sreg_prev = SREG; cli(); while (datlen--) { curbyte = (*data++); asm volatile(" ldi %0,8 \n\t" "loop%=: \n\t" " out %2,%3 \n\t" // '1' [01] '0' [01] - re #if (w1_nops & 1) w_nop1 #endif #if (w1_nops & 2) w_nop2 #endif #if (w1_nops & 4) w_nop4 #endif #if (w1_nops & 8) w_nop8 #endif #if (w1_nops & 16) w_nop16 #endif " sbrs %1,7 \n\t" // '1' [03] '0' [02] " out %2,%4 \n\t" // '1' [--] '0' [03] - fe-low " lsl %1 \n\t" // '1' [04] '0' [04] #if (w2_nops & 1) w_nop1 #endif #if (w2_nops & 2) w_nop2 #endif #if (w2_nops & 4) w_nop4 #endif #if (w2_nops & 8) w_nop8 #endif #if (w2_nops & 16) w_nop16 #endif " out %2,%4 \n\t" // '1' [+1] '0' [+1] - fe-high #if (w3_nops & 1) w_nop1 #endif #if (w3_nops & 2) w_nop2 #endif #if (w3_nops & 4) w_nop4 #endif #if (w3_nops & 8) w_nop8 #endif #if (w3_nops & 16) w_nop16 #endif " dec %0 \n\t" // '1' [+2] '0' [+2] " brne loop%=\n\t" // '1' [+3] '0' [+4] : "=&d"(ctr) : "r"(curbyte), "I"(_SFR_IO_ADDR(PORTx_ADDRESS(RGB_DI_PIN))), "r"(maskhi), "r"(masklo)); } SREG = sreg_prev; }