musiclight2/sk6812.c

/*
 * vim: sw=2 ts=2 expandtab
 *
 * "THE PIZZA-WARE LICENSE" (derived from "THE BEER-WARE LICENCE"):
 * Thomas Kolb <cfr34k@tkolb.de> wrote this file. As long as you retain this
 * notice you can do whatever you want with this stuff. If we meet some day,
 * and you think this stuff is worth it, you can buy me a pizza in return.
 * - Thomas Kolb
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <unistd.h>

#include <string.h>
#include <stdio.h>

#include "sk6812.h"

#define SET_COLOR    0
#define FADE_COLOR   1
#define ADD_COLOR    2
#define SET_FADESTEP 3

struct __attribute__((__packed__)) SK6812Packet {
  uint8_t action;
  uint16_t module;
  uint8_t data[4];
};

int sk6812_socket = -1;
struct __attribute__((__packed__)) SK6812Packet packetQueue[1024];
int queueIndex = 0;

// creates the socket needed for steering the LED strip
int sk6812_init(const char *host, unsigned short port) {
  struct addrinfo  hints;
  struct addrinfo *result;
  char portstr[6];

  memset(&hints, 0, sizeof(struct addrinfo));
  hints.ai_family = AF_UNSPEC;
  hints.ai_socktype = SOCK_DGRAM;
  hints.ai_flags = 0;
  hints.ai_protocol = 0;

  sprintf(portstr, "%u", port);

  if(getaddrinfo(host, portstr, &hints, &result) != 0) {
    perror("getaddrinfo() failed");
    return 1;
  }

  sk6812_socket = socket(result->ai_family, result->ai_socktype, result->ai_protocol);
  if (sk6812_socket == -1) {
    perror("socket() failed");
    freeaddrinfo(result);
    return 2;
  }

  if (connect(sk6812_socket, result->ai_addr, result->ai_addrlen) == -1) {
    perror("connect() failed");
    freeaddrinfo(result);
    return 3;
  }

  freeaddrinfo(result);

  return 0;
}

void sk6812_set_color(uint16_t module, uint8_t r, uint8_t g, uint8_t b, uint8_t w) {
  packetQueue[queueIndex].action  = SET_COLOR;
  packetQueue[queueIndex].module  = htons(module);
  packetQueue[queueIndex].data[0] = r;
  packetQueue[queueIndex].data[1] = g;
  packetQueue[queueIndex].data[2] = b;
  packetQueue[queueIndex].data[3] = w;
  queueIndex++;
}

void sk6812_fade_color(uint16_t module, uint8_t r, uint8_t g, uint8_t b, uint8_t w) {
  packetQueue[queueIndex].action  = FADE_COLOR;
  packetQueue[queueIndex].module  = htons(module);
  packetQueue[queueIndex].data[0] = r;
  packetQueue[queueIndex].data[1] = g;
  packetQueue[queueIndex].data[2] = b;
  packetQueue[queueIndex].data[3] = w;
  queueIndex++;
}

void sk6812_add_color(uint16_t module, uint8_t r, uint8_t g, uint8_t b, uint8_t w) {
  packetQueue[queueIndex].action  = ADD_COLOR;
  packetQueue[queueIndex].module  = htons(module);
  packetQueue[queueIndex].data[0] = r;
  packetQueue[queueIndex].data[1] = g;
  packetQueue[queueIndex].data[2] = b;
  packetQueue[queueIndex].data[3] = w;
  queueIndex++;
}

void sk6812_set_fadestep(uint8_t fadestep) {
  packetQueue[queueIndex].action  = SET_FADESTEP;
  packetQueue[queueIndex].data[0] = fadestep;
  queueIndex++;
}

int sk6812_commit(void) {
  if(send(sk6812_socket, packetQueue, queueIndex * sizeof(struct SK6812Packet), 0) == -1) {
    return 1;
  }

  queueIndex = 0;
  return 0;
}

void sk6812_shutdown() {
  close(sk6812_socket);
}