Method startBoundary

src/fl/chipsets/apa102.h:42–45

	SPI mSPI;

	void startBoundary() {
		mSPI.writeWord(START_FRAME >> 16);
		mSPI.writeWord(START_FRAME & 0xFFFF);
	}
	void endBoundary(int nLeds) {
		int nDWords = (nLeds/32);
		const fl::u8 b0 = fl::u8(END_FRAME >> 24 & 0x000000ff);