-- 74HC595.lua -- Written by John Longworth July 2016 -- ESP8266 connected to a 74HC595 by SPI --Connect Nodemcu D7 (GPIO13) to 74HC595 Data (pin 14) --Connect Nodemcu D5 (GPIO14) to 74HC595 Clock (pin 11) --Connect Nodemcu D8 (GPIO15) to 74HC595 Latch (pin 12) spi.setup(1, spi.MASTER, spi.CPOL_HIGH, spi.CPHA_LOW, spi.DATABITS_8, 0) latch = 8 gpio.mode(latch, gpio.OUTPUT) data = {1,2,4,8,16,32,64,128,0,128,64,32,16,8,4,2,1,0} function sendData(byte) -- Send data to 595 gpio.write(latch, gpio.LOW) spi.send(1,byte) gpio.write(latch, gpio.HIGH) end i=1 tmr.alarm(0,100,1,function() print(i) sendData(data[i]); i = i + 1 if (i > 18) then i = 1 end end)