temp_sensor_esp8266

pin=4
ow.setup(pin)
lastTemp=-999
function bxor(a,b)
	local r = 0
	for i = 0, 31 do
		if ( a % 2 + b % 2 == 1 ) then
			r = r + 2^i
		end
		a = a / 2
		b = b / 2
	end
	return r
end

tempSenseState=0
tmr.alarm(0, 1000, 1, function()
	function ServiceTempSensor()
		if (tempSenseState == 0) then
			ow.reset(pin)
			ow.skip(pin)
			ow.write(pin, 0x44, 1)
			tempSenseState = 1
		else
			ow.reset(pin)
			ow.skip(pin)
			ow.write(pin, 0xBE, 1)
			data = nil
			data = string.char(ow.read(pin))
			data = data .. string.char(ow.read(pin))
			t = (data:byte(1) + data:byte(2) * 256)
			if (t > 32768) then
				t = (bxor(t, 0xffff)) + 1
				t = (-1) * t
			end
			t = t *625
			lastTemp = t / 10000
			tempSenseState = 0
		end
	end
	ServiceTempSensor()
end)

-- TCP server	
server=net.createServer(net.TCP)
server:listen(80, function(conn)
	conn:on("receive", function(conn, payload)
		conn:send(tostring(lastTemp))
	end)
	conn:on("sent", function(conn) conn:close() end)
end)