Subversion Repositories neorv32

// #################################################################################################

// # << NEORV32 - Smart LED (NeoPixel/WS2812) Hardware Interface (NEOLED) Demo Program >>          #

// # ********************************************************************************************* #

// # BSD 3-Clause License                                                                          #

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// # Copyright (c) 2021, Stephan Nolting. All rights reserved.                                     #

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// # The NEORV32 Processor - https://github.com/stnolting/neorv32              (c) Stephan Nolting #

// #################################################################################################

/**********************************************************************//**

 * @file demo_neopixel/main.c

 * @author Stephan Nolting

 * @brief NeoPixel (WS2812) interface demo using the processor's smart LED interface (NEOLED).

 **************************************************************************/

#include <neorv32.h>

/**********************************************************************//**

 * @name User configuration

 **************************************************************************/

/**@{*/

/** UART BAUD rate */

#define BAUD_RATE 19200

/** Number of RGB LEDs in stripe (24-bit data) */

#define NUM_LEDS_24BIT (12)

/** Max intensity (0..255) */

#define MAX_INTENSITY (16)

/**@}*/

// prototypes

uint32_t hsv2rgb(int h, int v);

/**********************************************************************//**

 * Main function

 * This demo uses a 12-LED RGB ring

 *

 * @note This program requires the NEOLED controller to be synthesized (UART0 is optional).

 *

 * @return 0 if execution was successful

 **************************************************************************/

int main() {

  // capture all exceptions and give debug info via UART0

  // this is not required, but keeps us safe

  neorv32_rte_setup();

  // setup UART0 at default baud rate, no parity bits, no hw flow control

  neorv32_uart0_setup(BAUD_RATE, PARITY_NONE, FLOW_CONTROL_NONE);

  // check if NEOLED unit is implemented at all, abort if not

  if (neorv32_neoled_available() == 0) {

    neorv32_uart0_printf("Error! No NEOLED unit synthesized!\n");

    return 1;

  }

  // illustrate setup

  neorv32_uart0_printf("<<< NEORV32 NeoPixel (WS2812) hardware interface (NEOLED) demo >>>\n"

                       "(TM) 'NeoPixel' is a trademark of Adafruit Industries.\n\n"

                       "This demo uses the following LED setup:\n"

                       "NEORV32.neoled_o -> %u RGB-LEDs (24-bit)\n\n", (uint32_t)NUM_LEDS_24BIT);

  // use the "neorv32_neoled_setup_ws2812()" setup function here instead the raw "neorv32_neoled_setup()"

  // neorv32_neoled_setup_ws2812() will configure all timing parameters according to the WS2812 specs. for the current processor clock speed

  neorv32_neoled_setup_ws2812();

  neorv32_neoled_enable(); // enable module

  neorv32_neoled_set_mode(0); // mode = 0 = 24-bit

  // check NEOLED configuration

  neorv32_uart0_printf("Checking NEOLED configuration:\n"

                       " Hardware FIFO size: %u entries\n"

                       " Control register:   0x%x\n\n", neorv32_neoled_get_buffer_size(), NEORV32_NEOLED.CTRL);

  // clear all LEDs

  neorv32_uart0_printf("Clearing all LEDs...\n");

  int i;

  for (i=0; i<NUM_LEDS_24BIT; i++) {

    neorv32_neoled_write_blocking(0);

  }

  neorv32_cpu_delay_ms(500);

  // a simple animation example: rotating rainbow

  // this example uses BLOCKING NEOLED functions that check the FIFO flags before writing new data

  // non-blocking functions should only be used when checking the FIFO flags (half-full) in advance (for example using the NEOLED interrupt)

  neorv32_uart0_printf("Starting animation...\n");

  int angle = 0, led_id = 0;

  while (1) {

    for (led_id=0; led_id<NUM_LEDS_24BIT; led_id++) {

      // give every LED a different color

      neorv32_neoled_write_blocking(hsv2rgb(angle + (360/NUM_LEDS_24BIT) * led_id, MAX_INTENSITY));

    }

    angle += 1; // rotation increment per frame

    neorv32_neoled_strobe_blocking(); // send strobe ("RESET") command

    neorv32_cpu_delay_ms(10); // delay between frames

  }

  return 0;

}

/**********************************************************************//**

 * Convert HSV color to RGB.

 *

 * @note Very simple version: using integer arithmetic and ignoring saturation (saturation is always MAX).

 *

 * @param[in] h Hue (color angle), 0..359

 * @param[in] v Value (intensity), 0..255

 * @return LSB-aligned 24-bit RGB data [G,R,B]

 **************************************************************************/

uint32_t hsv2rgb(int h, int v) {

  h = h % 360;

  int r, g, b;

  int i = h / 60;

  int difs = h % 60;

  int rgb_adj = (v * difs) / 60;

  switch (i) {

    case 0:

      r = v;

      g = 0 + rgb_adj;

      b = 0;

      break;

    case 1:

      r = v - rgb_adj;

      g = v;

      b = 0;

      break;

    case 2:

      r = 0;

      g = v;

      b = 0 + rgb_adj;

      break;

    case 3:

      r = 0;

      g = v - rgb_adj;

      b = v;

      break;

    case 4:

      r = 0 + rgb_adj;

      g = 0;

      b = v;

      break;

    default:

      r = v;

      g = 0;

      b = v - rgb_adj;

      break;

  }

  uint32_t res = 0;

  res |= (((uint32_t)g) & 0xff) << 16;

  res |= (((uint32_t)r) & 0xff) << 8;

  res |= (((uint32_t)b) & 0xff) << 0;

  return res;

}