/* Copyright 2020 Aldehir Rojas * Copyright 2017 Mikkel (Duckle29) * * 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 "apa102.h" #include "quantum.h" #ifndef APA102_NOPS # if defined(__AVR__) # define APA102_NOPS 0 // AVR at 16 MHz already spends 62.5 ns per clock, so no extra delay is needed # elif defined(PROTOCOL_CHIBIOS) # include "hal.h" # if defined(STM32F0XX) || defined(STM32F1XX) || defined(STM32F3XX) || defined(STM32F4XX) || defined(STM32L0XX) # define APA102_NOPS (100 / (1000000000L / (STM32_SYSCLK / 4))) // This calculates how many loops of 4 nops to run to delay 100 ns # else # error("APA102_NOPS configuration required") # define APA102_NOPS 0 // this just pleases the compile so the above error is easier to spot # endif # endif #endif #define io_wait \ do { \ for (int i = 0; i < APA102_NOPS; i++) { \ __asm__ volatile("nop\n\t" \ "nop\n\t" \ "nop\n\t" \ "nop\n\t"); \ } \ } while (0) #define APA102_SEND_BIT(byte, bit) \ do { \ writePin(RGB_DI_PIN, (byte >> bit) & 1); \ io_wait; \ writePinHigh(RGB_CI_PIN); \ io_wait; \ writePinLow(RGB_CI_PIN); \ io_wait; \ } while (0) uint8_t apa102_led_brightness = APA102_DEFAULT_BRIGHTNESS; void static apa102_start_frame(void); void static apa102_end_frame(uint16_t num_leds); void static apa102_send_frame(uint8_t red, uint8_t green, uint8_t blue, uint8_t brightness); void static apa102_send_byte(uint8_t byte); void apa102_setleds(LED_TYPE *start_led, uint16_t num_leds) { LED_TYPE *end = start_led + num_leds; apa102_start_frame(); for (LED_TYPE *led = start_led; led < end; led++) { apa102_send_frame(led->r, led->g, led->b, apa102_led_brightness); } apa102_end_frame(num_leds); } // Overwrite the default rgblight_call_driver to use apa102 driver void rgblight_call_driver(LED_TYPE *start_led, uint8_t num_leds) { apa102_setleds(start_led, num_leds); } void static apa102_init(void) { setPinOutput(RGB_DI_PIN); setPinOutput(RGB_CI_PIN); writePinLow(RGB_DI_PIN); writePinLow(RGB_CI_PIN); } void apa102_set_brightness(uint8_t brightness) { if (brightness > APA102_MAX_BRIGHTNESS) { apa102_led_brightness = APA102_MAX_BRIGHTNESS; } else if (brightness < 0) { apa102_led_brightness = 0; } else { apa102_led_brightness = brightness; } } void static apa102_send_frame(uint8_t red, uint8_t green, uint8_t blue, uint8_t brightness) { apa102_send_byte(0b11100000 | brightness); apa102_send_byte(blue); apa102_send_byte(green); apa102_send_byte(red); } void static apa102_start_frame(void) { apa102_init(); for (uint16_t i = 0; i < 4; i++) { apa102_send_byte(0); } } void static apa102_end_frame(uint16_t num_leds) { // This function has been taken from: https://github.com/pololu/apa102-arduino/blob/master/APA102.h // and adapted. The code is MIT licensed. I think thats compatible? // // The data stream seen by the last LED in the chain will be delayed by // (count - 1) clock edges, because each LED before it inverts the clock // line and delays the data by one clock edge. Therefore, to make sure // the last LED actually receives the data we wrote, the number of extra // edges we send at the end of the frame must be at least (count - 1). // // Assuming we only want to send these edges in groups of size K, the // C/C++ expression for the minimum number of groups to send is: // // ((count - 1) + (K - 1)) / K // // The C/C++ expression above is just (count - 1) divided by K, // rounded up to the nearest whole number if there is a remainder. // // We set K to 16 and use the formula above as the number of frame-end // bytes to transfer. Each byte has 16 clock edges. // // We are ignoring the specification for the end frame in the APA102 // datasheet, which says to send 0xFF four times, because it does not work // when you have 66 LEDs or more, and also it results in unwanted white // pixels if you try to update fewer LEDs than are on your LED strip. uint16_t iterations = (num_leds + 14) / 16; for (uint16_t i = 0; i < iterations; i++) { apa102_send_byte(0); } apa102_init(); } void static apa102_send_byte(uint8_t byte) { APA102_SEND_BIT(byte, 7); APA102_SEND_BIT(byte, 6); APA102_SEND_BIT(byte, 5); APA102_SEND_BIT(byte, 4); APA102_SEND_BIT(byte, 3); APA102_SEND_BIT(byte, 2); APA102_SEND_BIT(byte, 1); APA102_SEND_BIT(byte, 0); }