cron.lua

local cron = require 'cron'

relay = {0, 1, 2, 3};

for x in pairs(relay) do
    gpio.mode(relay[x], gpio.OUTPUT);
end

pulser = gpio.pulse.build({
    {
        [relay[1]] = gpio.HIGH,
        [relay[2]] = gpio.LOW,
        delay = 999
    },
    {
        [relay[1]] = gpio.LOW,
        [relay[2]] = gpio.HIGH,
        delay = 999
    }
});

blink = cron.schedule("* * * * *", function()
    print('tick');
    
    pulser:start(function(pos, steps, offset, now)
        print(pos, steps, offset, now);
        return true;
    end);
    return true;
end);