Unverified Commit 726446fe authored by Daniel Friesel's avatar Daniel Friesel
Browse files

add support for reading the work period from the sensor

parent 231f24f4

README.md

+9 −6
Original line number Diff line number Diff line
@@ -46,12 +46,14 @@ port = softuart.setup(9600, 2, 1) 
port:on("data", 10, uart_callback)



function uart_callback(data)

	local pm25i, pm25d, pm10i, pm10d = sds011.parse_frame(data)

	if pm25i ~= nil then

		-- pm25i/pm10i contain the integer part (i.e., PM2.5 / PM10 value in µg/m³)

		-- pm25d/pm10d contain the decimal/fractional part (i.e., PM2.5 / PM10 fraction in .1 µg/m³, range 0 .. 9)

	if sds011.parse_frame(data) then

		-- PM values or work period have been updated

		if sds011.pm2_5i ~= nil then

			-- pm2_5i/pm10i contain the integer part (i.e., PM2.5 / PM10 value in µg/m³)

			-- pm2_5d/pm10d contain the decimal/fractional part (i.e., PM2.5 / PM10 fraction in .1 µg/m³, range 0 .. 9)

		else

		-- invalid checksum or non-data frame (i.e., acknowledgment of a write command)

			-- sds011.work_period has been updated after using sds011.set_work_period

		end

	end

end

```
@@ -68,6 +70,7 @@ Currently, the following commands are supported 
  * sleep == true: put sensor into sleep mode. The fan is turned off, no further measurements are performed

  * sleep == false: wake up sensor.

* `port:write(sds011.set_work_period(period))`

  * period == nil: request current work period; does not change it

  * period == 0: continuous operation (about one measurement per second)

  * 0 < *period* ≤ 30: about one measurement every *period* minutes; fan turned off in-between

init.lua

+12 −6
Original line number Diff line number Diff line
@@ -25,12 +25,13 @@ end 
function setup_client()

	print("Connected")

	gpio.write(ledpin, 1)

	port = softuart.setup(9600, 2, 1)

	port:on("data", 10, uart_callback)

	publishing_mqtt = true

	mqttclient:publish(mqtt_prefix .. "/state", "online", 0, 1, function(client)

		publishing_mqtt = false

		port:write(sds011.set_work_period(nil))

	end)

	port = softuart.setup(9600, 2, 1)

	port:on("data", 10, uart_callback)

end



function connect_mqtt()
@@ -55,8 +56,7 @@ function connect_wifi() 
end



function uart_callback(data)

	local pm25i, pm25f, pm10i, pm10f = sds011.parse_frame(data)

	if pm25i == nil then

	if not sds011.parse_frame(data) then

		print("Invalid or data-less SDS011 frame")

		return

	end
@@ -64,8 +64,14 @@ function uart_callback(data) 
	if sds011.work_period > 0 then

		work_period = string.format("%d min", sds011.work_period)

	end

	local json_str = string.format('{"pm2_5_ugm3": %d.%d, "pm10_ugm3": %d.%d, "rssi_dbm": %d, "period": "%s"}', pm25i, pm25f, pm10i, pm10f, wifi.sta.getrssi(), work_period)

	local influx_str = string.format("pm2_5_ugm3=%d.%d,pm10_ugm3=%d.%d", pm25i, pm25f, pm10i, pm10f)



	local json_str = string.format('{"rssi_dbm":%d,"period":"%s"', wifi.sta.getrssi(), work_period)

	if sds011.pm2_5i ~= nil then

		json_str = string.format('%s,"pm2_5_ugm3":%d.%d,"pm10_ugm3":%d.%d', json_str, sds011.pm2_5i, sds011.pm2_5f, sds011.pm10i, sds011.pm10f)

		local influx_str = string.format("pm2_5_ugm3=%d.%d,pm10_ugm3=%d.%d", sds011.pm2_5i, sds011.pm2_5f, sds011.pm10i, sds011.pm10f)

	end

	json_str = json_str .. '}'



	if not publishing_mqtt then

		watchdog:start(true)

		publishing_mqtt = true

sds011.lua

+23 −8
Original line number Diff line number Diff line
@@ -55,23 +55,38 @@ end 
function sds011.set_work_period(period)

	-- period == 0 : continuous operation, about one measurement per second

	-- period > 0  : about one measurement every <period> minutes, fan is turned off in-between

	if period < 0 or period > 30 then

	if period ~= nil and (period < 0 or period > 30) then

		return

	end

	sds011.work_period = period

	local cmd = string.char(c_head, c_id, c_workperiod, c_write, period)

	local op = c_write

	if period == nil then

		op = c_read

		period = 0

	end

	local cmd = string.char(c_head, c_id, c_workperiod, op, period)

	cmd = cmd .. string.char(0, 0, 0, 0, 0, 0, 0, 0, 0, 0)

	return sds011.finish_cmd(cmd)

end



function sds011.parse_frame(data)

	local header, command, pm25l, pm25h, pm10l, pm10h, id1, id2, sum, tail = struct.unpack("BBBBBBBBBB", data)

	if header ~= c_head or command ~= 0xc0 or (pm25l + pm25h + pm10l + pm10h + id1 + id2) % 256 ~= sum or tail ~= c_tail then

		return nil

	if header ~= c_head or (pm25l + pm25h + pm10l + pm10h + id1 + id2) % 256 ~= sum or tail ~= c_tail then

		return false

	end

	if command == 0xc0 then

		local pm25 = pm25h * 256 + pm25l

		local pm10 = pm10h * 256 + pm10l

		sds011.pm2_5i = pm25 / 10

		sds011.pm2_5f = pm25 % 10

		sds011.pm10i = pm10 / 10

		sds011.pm10f = pm10 % 10

		return true

	end

	if command == 0xc5 then

		sds011.work_period = pm10l

		return true

	end

	pm25 = pm25h * 256 + pm25l

	pm10 = pm10h * 256 + pm10l

	return pm25 / 10, pm25 % 10, pm10 / 10, pm10 % 10

	return false

end



return sds011