main.c

/*
 * Copyright (C) 2021  Patrick Pedersen

 * 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 3 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 <https://www.gnu.org/licenses/>.
 *
 */

/**
 * @file blink_loop.c
 * @author Patrick Pedersen
 * @date 2021-04-09
 *
 * @brief Blinks one or more WS2812 devices using a more memory efficient method than the blink_array.c example.
 *
 * The following example showcases how the Tiny-WS2812 library can
 * be used on AVR platforms to blink an entire WS2812 device in white.
 * Unlike the other blink example, we do not allocate a memory expensive
 * array for every single LED here, but instead loop the transmission of
 * a single RGB value until all WS2812 LEDs have been set.
 *
 * The advantage of this method is that we can save allot of memory, the
 * disadvantage is that this method is more prone to programming mistakes.
 *
 * @note Please ensure that the WS2812_TARGET_PLATFORM_AVR macro
 * is defined during compilation. This can either be done by specifying
 * -DWS2812_TARGET_PLATFORM_AVR in the build flags, or by uncommenting
 * the define WS2812_TARGET_PLATFORM_AVR directive below.
 */

// #define WS2812_TARGET_PLATFORM_AVR

#include <avr/io.h>
#include <util/delay.h>

#include <ws2812.h>

// Parameters - ALTER THESE TO CORRESPOND WITH YOUR OWN SETUP!
#define N_LEDS 17                ///< Number of LEDs on your WS2812 device(s)
#define DATA_PINS_PORT PORTB    ///< Port register used to communicate with the WS2812 device(s)
#define DATA_PINS_DDR DDRB      ///< Data direction register of the pin(s) used to communicate with the WS2812 device(s)
#define DATA_PINS {PB0}         ///< Pin(s) used to communicate with the WS2812 device(s)
#define RESET_TIME 70           ///< Reset time in microseconds (50us recommended by datasheet)
#define COLOR_ORDER grb         ///< Color order of your WS2812 LEDs (Typically grb or rgb)

// Colors
ws2812_rgb green = {0,255,0};

/**
 * Blinks one or more WS2812 device(s)
 */
int main()
{
    uint8_t pins[] = DATA_PINS; // Data pins
    ws2812_cfg cfg;             // Device configurationn
    ws2812 ws2812_dev;          // Device struct

    // Configure the WS2812 device struct
    cfg.port = &DATA_PINS_PORT;
    cfg.ddr = &DATA_PINS_DDR;
    cfg.pins = pins;
    cfg.n_dev = sizeof(pins);     // Number of devices driven by this struct
    cfg.rst_time_us = RESET_TIME;
    cfg.order = grb;

    if (ws2812_config(&ws2812_dev, &cfg) != 0) {
        // HANDLE ERROR...
        void;
    };

    // Prepare to transmit data
    ws2812_prep_tx(&ws2812_dev);

    // Program all LEDs to white
    for (unsigned int i = 0; i < N_LEDS; i++) {
        ws2812_tx(&ws2812_dev, &green, sizeof(green)/sizeof(ws2812_rgb));
        // THIS LOOP NEEDS TO RUN UNINTERRUPTED!
    }

    // Close transmission
    ws2812_close_tx(&ws2812_dev);

    return 0;
}