Understanding the APA102 Superled
Does FastLED implement this string led length dependent end fame as discussed in articles below?
In summary, each update of an APA102 based LED string should consist of the following:
1\. A start frame of 32 zero bits (<0x00> <0x00> <0x00> <0x00>)
2\. A 32 bit LED frame for each LED in the string (<0xE0+brightness>
3. An end frame consisting of at least (n/2) bits of 1, where n is the number of LEDs in the string.*