/*     RAM used (bytes) to show() 1 LED vs FastLED version

               | (1) #include | (2) CRGB,addLeds| (3) CHSV, show| Globals (1/2/3)| Flash used (1/2/3)
---------------|--------------|-----------------|---------------|----------------|-------------------
(0) No FastLED | 206          |                 |               | 192            | 1908          
FastLED 3.3.3  | 219 (+13)    | 287 (+68)       | 304 (+17)     | 205/273/285    | 1938/4012/5012
FastLED 3.4.0  | 219 (+13)    | 287 (+68)       | 304 (+17)     | 205/273/285    | 1938/4006/5000
FastLED 3.5.0  | 219 (+13)    | 287 (+68)       | 304 (+17)     | 205/273/285    | 1938/4082/5046
FastLED 3.6.0  | 219 (+13)    | 291 (+72)       | 308 (+17)     | 205/277/289    | 1938/4092/5056
FastLED 3.7.0  | 219 (+13)    | 291 (+72)       | 310 (+19)     | 205/277/289    | 1938/4080/5046
FastLED 3.7.1  | 219 (+13)    | 291 (+72)       | 310 (+19)     | 205/277/289    | 1938/4080/5046
FastLED 3.7.2  | 219 (+13)    | 291 (+72)       | 310 (+19)     | 205/277/289    | 1938/4080/5046
FastLED 3.7.3  | 219 (+13)    | 291 (+72)       | 310 (+19)     | 205/277/289    | 1938/4080/5046
FastLED 3.7.4  | 219 (+13)    | 299 (+80)       | 449 (+150)    | 205/285/297    | 1938/4102/5276
FastLED 3.7.5  | 219 (+13)    | 299 (+80)       | 449 (+150)    | 205/285/297    | 1938/4114/5288
FastLED 3.7.6  | 219 (+13)    | 299 (+80)       | 449 (+150)    | 205/285/297    | 1938/4114/5288
FastLED 3.7.7  | 219 (+13)    | 305 (+86)       | 455 (+150)    | 205/291/303    | 1938/4146/5320
FastLED 3.7.8  | 219 (+13)    | 305 (+86)       | 455 (+150)    | 205/291/303    | 1946/4154/5328
FastLED 3.9.0  | 223 (+17)    | 309 (+86)       | 337 (+28)     | 209/295/323    | 1946/4372/5224
FastLED 3.9.1  | 223 (+17)    | 309 (+86)       | 337 (+28)     | 209/295/323    | 1946/4372/5224
FastLED 3.9.2  | 223 (+17)    | 309 (+86)       | 337 (+28)     | 209/295/323    | 1946/4372/5224
FastLED 3.9.3  | 223 (+17)    | 309 (+86)       | 337 (+28)     | 209/295/323    | 1946/4372/5224
FastLED 3.9.4  | 223 (+17)    | 309 (+86)       | 337 (+28)     | 209/295/323    | 1946/4372/5224
FastLED 3.9.5  | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5170
FastLED 3.9.6  | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5170
FastLED 3.9.7  | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5170
FastLED 3.9.8  | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5168
FastLED 3.9.9  | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5168
FastLED 3.9.10 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5168
FastLED 3.9.11 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5168
FastLED 3.9.12 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5204
FastLED 3.9.13 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5234
FastLED 3.9.14 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5234
FastLED 3.9.15 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5234
FastLED 3.9.16 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5234
FastLED 3.9.17 | 1338 (+1134) | 1421 (+83)      | 1449 (+28)    | 869/952/980    | 6424/8792/9712
FastLED 3.9.18 | ? hangs      | 766 (+??)       | 794 (+28)     | 222/305/333    | 5168/7536/8456
FastLED 0f9da86| 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1948/4314/5234
FastLED 3.9.19 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5234
FastLED 3.9.20 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5234
FastLED 3.10.0 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5234
FastLED 3.10.1 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5234
FastLED 3.10.2 | 223 (+17)    | 306 (+83)       | 334 (+28)     | 209/292/320    | 1946/4314/5234

*/

#define TEST 3

#if (TEST >= 1)
#include <FastLED.h>
#endif

#if (TEST >= 2)
CRGB leds[1];
#endif

void setup() {
  Serial.begin(2000000);
  usedmem();
#if (TEST >= 2)
  FastLED.addLeds<NEOPIXEL, 2>(leds, 1);
#endif
}

void loop() {
#if (TEST >= 3)
  leds[0] = CHSV(random8(), random8(), random8());
  FastLED.show();
#endif
  usedmem();
  delay(500);
}

void usedmem() {
  extern unsigned int __heap_start;
  extern void *__brkval;
  uint16_t free_memory; // address used as a surrogate for the stack pointer
  if ((uint16_t)__brkval == 0)
    free_memory = ((uint16_t)&free_memory) - ((uint16_t)&__heap_start);
  else
    free_memory = ((uint16_t)&free_memory) - ((uint16_t)__brkval);
  Serial.print(F("Used mem: "));
  Serial.println(2048 - free_memory);
}