Using Nodemcu to drive a 74HC595 shift register

init.lua

latch_pin = 2

gpio.mode(latch_pin, gpio.OUTPUT)
gpio.write(latch_pin, gpio.LOW)
result = spi.setup(1, spi.MASTER, spi.CPOL_HIGH, spi.CPHA_LOW, spi.DATABITS_8, 0)
print(result)

while true do
  for i=1,255,1 do
    print(i)
    spi.send(1, i)

    gpio.write(latch_pin, gpio.HIGH)
    gpio.write(latch_pin, gpio.LOW)
    tmr.wdclr();
    tmr.delay(100000);
    tmr.wdclr();
  end
end

Connect Nodemcu D7 to 74HC595 Data (pin 14)
Connect Nodemcu D5 to 74HC595 Clock (pin 11)
Connect Nodemcu D2 to 74HC595 Latch (pin 12)

Super useful! Thanks!