X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=led%2Fws2801%2FREADME;h=4c87282653236e6915ac363e150b7cd9d2e00142;hb=50c0fd5b131ef86551faafa7e34b986fbd161356;hp=c8385d8708866feb183e156ecfc922b2b7bfbf9c;hpb=13f998d402108f2777925e1b077e7c2c226339e9;p=sigrok-dumps.git diff --git a/led/ws2801/README b/led/ws2801/README index c8385d8..4c87282 100644 --- a/led/ws2801/README +++ b/led/ws2801/README @@ -2,39 +2,40 @@ WS2801 LED strip ------------------------------------------------------------------------------- -This is a capture of data output an LED universes of 50 RGB LEDS. +This is a capture of data output to a LED universe of 50 RGB LEDs. -Every universe at full capacity of has a frame size of 768 bytes and can clock +Every universe at full capacity has a frame size of 768 bytes and can clock out at roughly 100 frames per second. Details: - Koen Kooi's evil vendor tree: https://github.com/koenkooi/kernel - - PRU WS2801 firmware: https://github.com/mranostay/ws28xx-lighting-pru + - PRU WS28xx firmware: https://github.com/mranostay/ws28xx-lighting-pru - WS2801 datasheet: http://www.adafruit.com/datasheets/WS2801.pdf -WS2812B protocol overview -------------------------- +WS2801 protocol overview +------------------------ -Each LED receives and the stores the first 24-bits of RGB ordered data then +Each LED receives and then stores the first 24-bits of RGB ordered data then passes any more out the Data Output pin to the next LED in the chain. -There is no CS line but latching is done when CLK is held low for >500 uS +There is no CS line but latching is done when CLK is held low for >500 uS. -This functions as a "reverse" shift register and allows the strip length not to -be defined in the protocol. +This functions as a "reverse" shift register and allows the strip length not +to be defined in the protocol. Logic analyzer setup -------------------- -The logic analzyer used was a Saleae Logic16 (at 5mhz) +The logic analyzer used was a Saleae Logic16 (at 5MHz): - Probe WS2812B LED strip - ------------------------- + Probe WS2801 LED strip + ---------------------------- 1 (black) Universe #1 2 (brown) Clock + Data ---- @@ -44,3 +45,4 @@ The sigrok command line used was: sigrok-cli --driver saleae-logic16 --samples 10M --config samplerate=5mhz \ -p 0=UNI1,1=CLK -o ws2801_2ch_5mhz.sr +