Nodemcu connecting with max113300

init.lua

pin = 8;
gpio.mode(pin,gpio.OUTPUT);
gpio.write(pin,gpio.HIGH);
spi.setup(1, spi.MASTER, spi.CPOL_LOW, spi.CPHA_LOW, spi.DATABITS_8, 0,spi.FULLDUPLEX);
gpio.write(pin,gpio.LOW);

function readRegister(address)
    gpio.write(pin,gpio.HIGH);
    gpio.write(pin,gpio.LOW);
    spi.send(1, bit.lshift(0x01, address));
    r1 = {spi.send(1, 0)};
    r2 = {spi.send(1, 0)};
    bb = bit.lshift(r1[2], 8);
    print (bb);
    print (r2[2]);
    print("==" .. bb+r2[2]);
    gpio.write(pin,gpio.HIGH);
end

function writeRegister(address, value)
    gpio.write(pin,gpio.HIGH);
    gpio.write(pin,gpio.LOW);
    spi.send(1, bit.lshift(0x01, address));
    spi.send(1, bit.rshift(8, value));
    spi.send(1, bit.band(0xFF, value));
    gpio.write(pin,gpio.HIGH);
end