local do_circle = function(pos)

	local size = 3
	local step = 4

	for i = 0, 360, step do

		local angle = (i * math.pi / 180)
		local x = size * math.cos(angle)
		local z = size * math.sin(angle)
		local newpos = {x = pos.x + x, y = pos.y, z = pos.z + z}

		minetest.add_particle({
			pos = newpos,
			velocity = {x = 0, y = 0, z = 0},
			acceleration = {x = 0, y = 0, z = 0},
			expirationtime = 0.25,
			collisiondetection = false,
			texture = "default_wood.png",
			size = 5,
			glow = 15,
		})
	end
end

minetest.register_node("test:block", {
	description = "Test Node",
	tiles = {"default_wood.png"},
	light_source = default.LIGHT_MAX,
	groups = {dig_immediate = 3},
	on_construct = function(pos)
		minetest.get_node_timer(pos):start(0.4) -- start timer
	end,
	on_timer = function(pos, elapsed)
		do_circle(pos)
		minetest.get_node_timer(pos):start(1.0) -- set timer to every 1 second
	end,
	-- unaffected by explosions
	on_blast = function() end,
})