NeoPixelRealtimeRGB.ino

#include <ESP8266WiFi.h>

// ----- sscanf() function -----
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>
 
#define MAXLN 200
#define ISSPACE " \t\n\r\f\v"
// -----------------------------

#include <Adafruit_NeoPixel.h>

#define PIN            D1
#define NUMPIXELS      8

WiFiServer server(88);
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  Serial.begin(115200);
  WiFi.mode(WIFI_AP);

  server.begin();
  pixels.begin();
  show(0, 0, 0);
}

void loop() {
  WiFiClient client = server.available();
  if (client) {
    Serial.println("New client");
    while (client.connected()) {
      if (client.available()) {
        String line = client.readStringUntil('\r');
        client.readStringUntil('\n');
        Serial.println(line);
        int r = 0, g = 0, b = 0;
        if (sscanf(line.c_str(), "%d,%d,%d", &r, &g, &b) > 0)
          show(r, g, b);
      }
      delay(1);
    }
  
    delay(10);
    client.stop();
    Serial.println("Client disconnect");
  }
  delay(10);
}

void show(int r, int g, int b) {
  for (int i=0;i<NUMPIXELS;i++)
    pixels.setPixelColor(i, pixels.Color(r, g, b));
  pixels.show();
}


 
size_t strcspn (const char *p, const char *s) {
  int i, j;
 
  for (i = 0; p[i]; i++) {
    for (j = 0; s[j]; j++) {
      if (s[j] == p[i])
        break;
      }
      if (s[j])
        break;
  }
  return (i);
}
 
char * _getbase(char *p, int *basep) {
  if (p[0] == '0') {
    switch (p[1]) {
      case 'x':
        *basep = 16;
        break;
      case 't': case 'n':
        *basep = 10;
        break;
      case 'o':
        *basep = 8;
         break;
      default:
        *basep = 10;
        return (p);
    }
    return (p + 2);
  }
  *basep = 10;
  return (p);
}
 
/*
 *  _atob(vp,p,base)
 */
int _atob (uint32_t *vp, char *p, int base) {
  uint32_t value, v1, v2;
  char *q, tmp[20];
  int digit;
 
  if (p[0] == '0' && (p[1] == 'x' || p[1] == 'X')) {
    base = 16;
    p += 2;
  }
 
  if (base == 16 && (q = strchr (p, '.')) != 0) {
    if (q - p > sizeof(tmp) - 1)
      return (0);
 
    strncpy (tmp, p, q - p);
    tmp[q - p] = '\0';
    if (!_atob (&v1, tmp, 16))
      return (0);
 
    q++;
    if (strchr (q, '.'))
      return (0);
 
    if (!_atob (&v2, q, 16))
      return (0);
    *vp = (v1 << 16) + v2;
    return (1);
  }
 
  value = *vp = 0;
  for (; *p; p++) {
    if (*p >= '0' && *p <= '9')
      digit = *p - '0';
    else if (*p >= 'a' && *p <= 'f')
      digit = *p - 'a' + 10;
    else if (*p >= 'A' && *p <= 'F')
      digit = *p - 'A' + 10;
    else
      return (0);
 
    if (digit >= base)
      return (0);
    value *= base;
    value += digit;
  }
  *vp = value;
  return (1);
}
 
/*
 *  atob(vp,p,base)
 *      converts p to binary result in vp, rtn 1 on success
 */
int atob(uint32_t *vp, char *p, int base) {
  uint32_t v;
  if (base == 0)
    p = _getbase (p, &base);
  if (_atob (&v, p, base)) {
    *vp = v;
    return (1);
  }
  return (0);
}
 
/*
 *  vsscanf(buf,fmt,ap)
 */
 
int vsscanf (const char *buf, const char *s, va_list ap) {
    uint32_t count, noassign, width, base, lflag;
    const char *tc;
    char *t, tmp[MAXLN];
 
  count = noassign = width = lflag = 0;
  while (*s && *buf) {
  while (isspace (*s))
    s++;
  if (*s == '%') {
    s++;
    for (; *s; s++) {
      if (strchr ("dibouxcsefg%", *s))
        break;
      if (*s == '*')
        noassign = 1;
      else if (*s == 'l' || *s == 'L')
        lflag = 1;
      else if (*s >= '1' && *s <= '9') {
        for (tc = s; isdigit (*s); s++);
        strncpy (tmp, tc, s - tc);
        tmp[s - tc] = '\0';
        atob (&width, tmp, 10);
        s--;
      }
    }
    if (*s == 's') {
      while (isspace (*buf))
        buf++;
      if (!width)
        width = strcspn (buf, ISSPACE);
      if (!noassign) {
        strncpy (t = va_arg (ap, char *), buf, width);
        t[width] = '\0';
      }
      buf += width;
    } else if (*s == 'c') {
      if (!width)
        width = 1;
      if (!noassign) {
        strncpy (t = va_arg (ap, char *), buf, width);
        t[width] = '\0';
      }
      buf += width;
    } else if (strchr ("dobxu", *s)) {
      while (isspace (*buf))
        buf++;
      if (*s == 'd' || *s == 'u')
        base = 10;
      else if (*s == 'x')
        base = 16;
      else if (*s == 'o')
        base = 8;
      else if (*s == 'b')
        base = 2;
      if (!width) {
        if (isspace (*(s + 1)) || *(s + 1) == 0)
          width = strcspn (buf, ISSPACE);
        else
          width = strchr (buf, *(s + 1)) - buf;
      }
      strncpy (tmp, buf, width);
      tmp[width] = '\0';
      buf += width;
      if (!noassign)
        atob (va_arg (ap, uint32_t *), tmp, base);
    }
    if (!noassign)
      count++;
      width = noassign = lflag = 0;
      s++;
    } else {
      while (isspace (*buf))
      buf++;
      if (*s != *buf)
        break;
      else
        s++, buf++;
    }
  }
  return (count);
}
 
 
int sscanf (const char *buf, const char *fmt, ...) {
  int count;
  va_list ap;
   
  va_start(ap, fmt);
  count = vsscanf (buf, fmt, ap);
  va_end(ap);
  return count;
}