Another Sensor-to-Switch Thread

[mighkel]

Problem:
How do I get my temperature setpoints to activate my switch? (thermostat operation) I have a feeling it’s something stupid to connect that last dot. I’ve just been staring at this for so long, it’s time to bounce it off of someone else’s head.

What am I trying to do?
Short: Write a flow to operate a switch based on temperature setpoint.
Long: Learn this whole IoT ‘thing’, and automate a greenhouse. Specifically, extract temperature and humidity data into a useful format, so I can automate the control of switches for fans, pumps, and other devices, and log all data, with the long-term goal of automating everything one would want to automate in a greenhouse.

What have I tried?
Seems like everything, but obviously not! LOL More background below. Sorry for the book, but I hope I was concise enough up-front that you only have to read down to the graphics.

What is the result of what I've tried?
I have a flow that picks up ALL of the data from a DHT11 (DHT3) with a parsed output. I have flows that successfully control wifi switches... finally. I seem to get a clean message from the sensor to a point at which the switch (SON1) would connect. Once I connect the switch, I get a “failure to parse JSON” error from the mqtt_subscribe node, and the switch does not respond. AAARRRRGHH!

Here's the flow that seems to get the operation all the way to the end:

When I connect the switch:

MQTT_subscription node:

Change node:

Software versions and configuration:
Raspbian 10 Buster
Mosquitto 1.6.8
Node-Red 1.0.5
Tasmota 8.2.0 ((tasmota.bin) Sonoff switches)
Tasmota 8.3.0 ((tasmota-sensors.bin (DHT3 only)

Hardware:
(1) Raspberry Pi 4 B, 4GB (Raspi)
(1) Sonoff 4CHAN Pro R2 (SON4CHAN)
(6) Sonoff Basic WiFi Switch (SON1, SON2, SON3,…)
(1) ESP8266MOD (NodeMCU – Amica) with DHT11 (DHT3)

Background:
Not a programmer, but trying to learn.
Not a Linux guy, but trying to learn.
I bought a handful of ESP8266 modules and DHT11 sensors. I managed to program them via Arduino IDE, and even got a few to publish data to adafruit io feeds. At this point, I’d never heard of MQTT. I was just excited that I got that far, having no programming or IoT experience. Just for fun, the public feed for my greenhouse temperature is still located here: https://io.adafruit.com/mighkel/feeds/dht1-overlay.dht1-temp

I stumbled on to Rui’s tutorials at RandomNerd Labs, and decided I wanted my own MQTT server. Following along, I was able to get my Raspi up and running with Mosquitto and Node-Red. I picked up a few Sonoff devices and an FTDI programmer, soldered on some headers, and managed to get all of the devices loaded up with a working Tasmota firmware. I also loaded one of the ESP8266/DHT11 packages with Tasmota, and it is reading temp/humidity/dewpoint.

After several days of not being able to connect the dots from Sonoff switches to Node-Red, I finally stumbled on to the right solution (server authentication) and can now control switches via Node-Red.

A few more days of trying to get the raw sensor data parsed into a useable msg format, I finally stumbled onto the “parsed JSON object” output setting on the mqtt sub node. A little (ok, a lot) more reading, and I got a little further including change node to move the message into a number object that I can use… in theory.

I'll try to write all of this up... haha, ok, since it's pretty much written up here, I'll start a thread in Projects topic to chronicle the whole greenhouse project from a total-newb point of view.

[bakman2]

You need to set the topic to: cmnd/SON/power with a payload of ON/OFF, thus add a set msg.topic to....

People can help if you also paste the flow here (with some dummy data instead of your mqtt nodes), so that we can what is happening.

And a small tip, set the debug nodes output to complete msg object

To simplify your flow:

The change node looks like this (using JSONata), it will output ON if it higher than 16:

Example flow

[{"id":"8aca5766.617388","type":"inject","z":"5b57bfa8.a5f29","name":"tele/DHT3/SENSOR - 18 degrees","topic":"tele/DHT3/SENSOR","payload":"{\"DHT11\":{\"temperature\":18.5}}","payloadType":"json","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":490,"y":120,"wires":[["1d7d61c6.b04b9e"]]},{"id":"a1da0430.1d7c38","type":"debug","z":"5b57bfa8.a5f29","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":914,"y":144,"wires":[]},{"id":"1d7d61c6.b04b9e","type":"change","z":"5b57bfa8.a5f29","name":"","rules":[{"t":"set","p":"topic","pt":"msg","to":"cmnd/SON/POWER","tot":"str"},{"t":"set","p":"payload","pt":"msg","to":"(payload.DHT11.temperature >16) ? \"ON\" : \"OFF\"","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":728,"y":144,"wires":[["a1da0430.1d7c38"]]},{"id":"cd18a642.b7f31","type":"inject","z":"5b57bfa8.a5f29","name":"tele/DHT3/SENSOR - 15 degrees","topic":"tele/DHT3/SENSOR","payload":"{\"DHT11\":{\"temperature\":15}}","payloadType":"json","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":490,"y":192,"wires":[["1d7d61c6.b04b9e"]]}]

For the json errors, you might want to check first if you receive a number then pass.

[mighkel]

@bakman2 Thanks! And sorry, I meant to include the code, but got side-tracked.

So, in my 'round-a-bout' flow, simply plugging in "set msg.topic..." per your instructions made it all work correctly. Many thanks again for that!
Here's what the working flow looks like now:

[{"id":"64179d70.37f584","type":"tab","label":"Temp-to-Switch Lite","disabled":false,"info":""},{"id":"a6146e16.0e3c5","type":"mqtt in","z":"64179d70.37f584","name":"","topic":"tele/DHT3/SENSOR/#","qos":"2","datatype":"json","broker":"741d5b6a.d93184","x":120,"y":100,"wires":[["43b33431.c1f09c","3e60a5f9.880eaa"]]},{"id":"3e60a5f9.880eaa","type":"change","z":"64179d70.37f584","name":"Convert Temp","rules":[{"t":"set","p":"topic","pt":"msg","to":"cmnd/SON1/POWER","tot":"str"},{"t":"move","p":"payload.DHT11.Temperature","pt":"msg","to":"payload","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":340,"y":100,"wires":[["6f62f27b.16231c","18f30ac6.df62c5"]]},{"id":"f52d114.21704f","type":"debug","z":"64179d70.37f584","name":"Test OFF","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":800,"y":60,"wires":[]},{"id":"6f62f27b.16231c","type":"switch","z":"64179d70.37f584","name":"Setpoints","property":"payload","propertyType":"msg","rules":[{"t":"lte","v":"20","vt":"num"},{"t":"gt","v":"20","vt":"str"}],"checkall":"true","repair":false,"outputs":2,"x":520,"y":100,"wires":[["f049f521.038298"],["6c10efe7.0b3d3"]]},{"id":"f049f521.038298","type":"change","z":"64179d70.37f584","name":"OFF","rules":[{"t":"set","p":"payload","pt":"msg","to":"OFF","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":670,"y":80,"wires":[["f52d114.21704f","cb52fc6e.77601"]]},{"id":"6c10efe7.0b3d3","type":"change","z":"64179d70.37f584","name":"ON","rules":[{"t":"set","p":"payload","pt":"msg","to":"ON","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":670,"y":120,"wires":[["90633418.e45e98","cb52fc6e.77601"]]},{"id":"90633418.e45e98","type":"debug","z":"64179d70.37f584","name":"Test ON","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":800,"y":160,"wires":[]},{"id":"cb52fc6e.77601","type":"mqtt out","z":"64179d70.37f584","name":"SON1","topic":"","qos":"","retain":"","broker":"741d5b6a.d93184","x":830,"y":100,"wires":[]},{"id":"43b33431.c1f09c","type":"debug","z":"64179d70.37f584","name":"Parsed Sensor Data","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":360,"y":160,"wires":[]},{"id":"18f30ac6.df62c5","type":"debug","z":"64179d70.37f584","name":"Converted Temp","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":540,"y":40,"wires":[]},{"id":"741d5b6a.d93184","type":"mqtt-broker","z":"","name":"YOUR_BROKER","broker":"111.111.111.111","port":"1883","clientid":"","usetls":false,"compatmode":false,"keepalive":"60","cleansession":true,"birthTopic":"","birthQos":"0","birthPayload":"","closeTopic":"","closeQos":"0","closePayload":"","willTopic":"","willQos":"0","willPayload":""}]

I had mixed results playing with the flow you posted though. Having plugged in my sub & pub nodes, I got it turn on the switch at the setpoint, but couldn't get it to turn the switch off. I'll have to spend some time dinking with it until I understand what's going on there. It appears to be a much more efficient way than the flow I wrote to do it, if one can just work the code right. I have a bit to learn about json syntax though!

[mighkel]

Since I'm excited about finally getting something to work, here's a flow that works with a Sonoff 4Chan R2 relay to ramp up/down fan speeds per various temperature ranges. I know it's not the most elegant (and probably not most effective) way to do it, but it was fun to go to a next step.

[{"id":"c08d4bd5.6e59b8","type":"tab","label":"Temp-to-Switch","disabled":false,"info":""},{"id":"add06c5c.a4478","type":"mqtt in","z":"c08d4bd5.6e59b8","name":"","topic":"tele/DHT3/SENSOR/#","qos":"2","datatype":"json","broker":"741d5b6a.d93184","x":120,"y":180,"wires":[["57a102dd.0a077c","735c8365.001bcc"]]},{"id":"57a102dd.0a077c","type":"change","z":"c08d4bd5.6e59b8","name":"Convert Temp","rules":[{"t":"set","p":"topic","pt":"msg","to":"cmnd/SON4CHAN","tot":"str"},{"t":"move","p":"payload.DHT11.Temperature","pt":"msg","to":"payload","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":340,"y":180,"wires":[["17c37f58.1c0b81"]]},{"id":"dbedf9ee.cea3f8","type":"debug","z":"c08d4bd5.6e59b8","name":"Temperature F","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":680,"y":140,"wires":[]},{"id":"17c37f58.1c0b81","type":"unit-converter","z":"c08d4bd5.6e59b8","category":"temperature","inputUnit":"C","outputUnit":"F","inputField":"payload","outputField":"payload","inputFieldType":"msg","outputFieldType":"msg","name":"C-to-F","x":510,"y":180,"wires":[["dbedf9ee.cea3f8","7b7d119a.a6d92"]]},{"id":"7b7d119a.a6d92","type":"switch","z":"c08d4bd5.6e59b8","name":"Setpoints","property":"payload","propertyType":"msg","rules":[{"t":"btwn","v":"0","vt":"num","v2":"50","v2t":"num"},{"t":"btwn","v":"50.01","vt":"num","v2":"60","v2t":"num"},{"t":"btwn","v":"60.01","vt":"num","v2":"70","v2t":"num"},{"t":"gt","v":"70.1","vt":"str"}],"checkall":"true","repair":false,"outputs":4,"x":540,"y":300,"wires":[["6075b92f.2490f8","8df024b0.693298","a24a92db.8c643","c4065f02.c184f"],["9145984b.e92e48","8df024b0.693298","a24a92db.8c643","48f00e4b.0177a"],["6075b92f.2490f8","9145984b.e92e48","a24a92db.8c643","db4b657.dc84598"],["9145984b.e92e48","6075b92f.2490f8","8df024b0.693298","526521be.3a00f"]]},{"id":"9145984b.e92e48","type":"change","z":"c08d4bd5.6e59b8","name":"RELAY1 OFF","rules":[{"t":"set","p":"topic","pt":"msg","to":"cmnd/SON4CHAN/POWER1","tot":"str"},{"t":"set","p":"payload","pt":"msg","to":"OFF","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":1100,"y":160,"wires":[["d9b5ae9c.1fc91"]]},{"id":"5c2e530b.b731dc","type":"change","z":"c08d4bd5.6e59b8","name":"RELAY1 ON","rules":[{"t":"set","p":"topic","pt":"msg","to":"cmnd/SON4CHAN/POWER1","tot":"str"},{"t":"set","p":"payload","pt":"msg","to":"ON","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":1090,"y":200,"wires":[["d9b5ae9c.1fc91"]]},{"id":"d9b5ae9c.1fc91","type":"mqtt out","z":"c08d4bd5.6e59b8","name":"SON4CHAN","topic":"","qos":"2","retain":"true","broker":"741d5b6a.d93184","x":1390,"y":340,"wires":[]},{"id":"735c8365.001bcc","type":"debug","z":"c08d4bd5.6e59b8","name":"Parsed Sensor Data","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":360,"y":140,"wires":[]},{"id":"d29fcb00.8269c8","type":"inject","z":"c08d4bd5.6e59b8","name":"","topic":"cmnd/SON4CHAN/","payload":"55","payloadType":"num","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":260,"y":280,"wires":[["7b7d119a.a6d92"]]},{"id":"b227547a.28c448","type":"inject","z":"c08d4bd5.6e59b8","name":"","topic":"cmnd/SON4CHAN/","payload":"65","payloadType":"num","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":260,"y":320,"wires":[["7b7d119a.a6d92"]]},{"id":"58c10966.0a8608","type":"inject","z":"c08d4bd5.6e59b8","name":"","topic":"cmnd/SON4CHAN/","payload":"45","payloadType":"num","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":260,"y":240,"wires":[["7b7d119a.a6d92"]]},{"id":"6075b92f.2490f8","type":"change","z":"c08d4bd5.6e59b8","name":"RELAY2 OFF","rules":[{"t":"set","p":"topic","pt":"msg","to":"cmnd/SON4CHAN/POWER2","tot":"str"},{"t":"set","p":"payload","pt":"msg","to":"OFF","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":1100,"y":260,"wires":[["d9b5ae9c.1fc91"]]},{"id":"ba7e61cc.47da8","type":"change","z":"c08d4bd5.6e59b8","name":"RELAY2 ON","rules":[{"t":"set","p":"topic","pt":"msg","to":"cmnd/SON4CHAN/POWER2","tot":"str"},{"t":"set","p":"payload","pt":"msg","to":"ON","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":1090,"y":300,"wires":[["d9b5ae9c.1fc91"]]},{"id":"8df024b0.693298","type":"change","z":"c08d4bd5.6e59b8","name":"RELAY3 OFF","rules":[{"t":"set","p":"topic","pt":"msg","to":"cmnd/SON4CHAN/POWER3","tot":"str"},{"t":"set","p":"payload","pt":"msg","to":"OFF","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":1100,"y":360,"wires":[["d9b5ae9c.1fc91"]]},{"id":"422d86ec.058348","type":"change","z":"c08d4bd5.6e59b8","name":"RELAY3 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0.5s","pauseType":"delay","timeout":".5","timeoutUnits":"seconds","rate":"1","nbRateUnits":"1","rateUnits":"second","randomFirst":"1","randomLast":"5","randomUnits":"seconds","drop":false,"x":930,"y":200,"wires":[["5c2e530b.b731dc"]]},{"id":"741d5b6a.d93184","type":"mqtt-broker","z":"","name":"YOUR_BROKER","broker":"111.111.111.111","port":"1883","clientid":"","usetls":false,"compatmode":false,"keepalive":"60","cleansession":true,"birthTopic":"","birthQos":"0","birthPayload":"","closeTopic":"","closeQos":"0","closePayload":"","willTopic":"","willQos":"0","willPayload":""}]

[bakman2]

Please export your flow again, read this post and edit your post.

[mighkel]

Sorry about that. I edited it and followed directions, but it still doesn't look right. How do you get it on one line like your example above?

[bakman2]

It is key that you export your flow again (as it is already incorrectly formatted now), then edit your post and click this icon and past the code between the backticks.

[zenofmud]

three back tics, then your code gos onthe next line then on the next line three more back tics.

I edited it for you.

[mighkel]

Thanks for the help and the patience guys!
I went ahead and re-exported the flows for both posts, and fixed post #3.