/stm8-ws2812b

Making clock with stm8 and ws2812b ring

Primary LanguageC

stm8-ws2812b

WS2812B timings

  • 0: 0.4 us high, 0.85 us low
  • 1: 0.8 us high, 0.45 us low
  • reset: 50+ us low
  • half bit accuracy: ± 150 ns
  • TH+TL = 1.25 us ± 600 ns

using nops

At 16 MHz

  • T0H - 5 nops
  • T1H - 7 nops

using timer

At 8 MHz clock

  • T0H = 0.4 us: 3 x 0.125 = 0.375 (error: -0.025)
  • T0L = 0.85 us: 7 x 0.125 = 0.875 (error: -0.025)
  • T1H = 0.8 us: 6 x 0.125 = 0.75 (error: -0.050)
  • T1L = 0.45 us: 4 x 0.125 = 0.5 (error: +0.050)

Seems acceptable, but loading next bit will take more than few tacts. Got to load byte, check bit, load CC value. Might have to use onle pulse mode, on CC load new value and restart timer.