Hi,
I am new in node-red. I have temp humidity and barometric pressure sensors (30 pcs) in different places. Every sensor send me a message to rs485 every 15-20 sec. It is a lot of data. I want to do this: with each message from each sensor do average and after a couple of time send it to MySQL database which is on server.
I try to do aggregate for every sensor, but for now, there are 30 sensors.
How to do this?
Message data looks like this.
payload: [{sensor id, humidity, temperature, pressure}]
Thanks
1 - why are you taking the readings so often?
2 - have you looked at the influx db? You can store the data and create rules to consolidate it
You should be able to use the split, smooth and join nodes to average nth number of readings, using sensor_id and readings property names as unique topics.
e.g.
[{"id":"d2137b3d.ea539","type":"inject","z":"30af2d3e.d94ea2","name":"1","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"[{\"sensor_id\":1,\"humidity\":30,\"temperature\":10,\"pressure\":500}]","payloadType":"json","x":110,"y":1920,"wires":[["234d0a8f.1b7c2e"]]},{"id":"234d0a8f.1b7c2e","type":"change","z":"30af2d3e.d94ea2","name":"","rules":[{"t":"move","p":"payload[0]","pt":"msg","to":"payload","tot":"msg"},{"t":"move","p":"payload.sensor_id","pt":"msg","to":"id","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":270,"y":1980,"wires":[["8ec0f7a.56a1408"]]},{"id":"816ff415.94e3c8","type":"inject","z":"30af2d3e.d94ea2","name":"1","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"[{\"sensor_id\":1,\"humidity\":60,\"temperature\":20,\"pressure\":1000}]","payloadType":"json","x":120,"y":1980,"wires":[["234d0a8f.1b7c2e"]]},{"id":"7db6ef6f.82ca9","type":"inject","z":"30af2d3e.d94ea2","name":"2","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"[{\"sensor_id\":2,\"humidity\":60,\"temperature\":20,\"pressure\":1000}]","payloadType":"json","x":110,"y":2040,"wires":[["234d0a8f.1b7c2e"]]},{"id":"e07d32a9.9a289","type":"inject","z":"30af2d3e.d94ea2","name":"2","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"[{\"sensor_id\":2,\"humidity\":30,\"temperature\":10,\"pressure\":500}]","payloadType":"json","x":118.33332824707031,"y":2080.66650390625,"wires":[["234d0a8f.1b7c2e"]]},{"id":"8ec0f7a.56a1408","type":"split","z":"30af2d3e.d94ea2","name":"","splt":"\\n","spltType":"str","arraySplt":1,"arraySpltType":"len","stream":false,"addname":"topic","x":430,"y":1980,"wires":[["f0eeafc0.0788b"]]},{"id":"f0eeafc0.0788b","type":"change","z":"30af2d3e.d94ea2","name":"","rules":[{"t":"set","p":"topic","pt":"msg","to":"$$.topic & $$.id","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":590,"y":1980,"wires":[["e0bfe459.990cd"]]},{"id":"e0bfe459.990cd","type":"smooth","z":"30af2d3e.d94ea2","name":"","property":"payload","action":"mean","count":"3","round":"2","mult":"multi","reduce":true,"x":760,"y":1980,"wires":[["608402e6.8c6294"]]},{"id":"608402e6.8c6294","type":"join","z":"30af2d3e.d94ea2","name":"","mode":"auto","build":"string","property":"payload","propertyType":"msg","key":"topic","joiner":"\\n","joinerType":"str","accumulate":false,"timeout":"","count":"","reduceRight":false,"reduceExp":"","reduceInit":"","reduceInitType":"","reduceFixup":"","x":890,"y":1980,"wires":[["3c623628.42c482"]]},{"id":"3c623628.42c482","type":"change","z":"30af2d3e.d94ea2","name":"","rules":[{"t":"move","p":"id","pt":"msg","to":"payload.sensor_id","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":610,"y":2040,"wires":[["8043f003.11f8b8"]]},{"id":"8043f003.11f8b8","type":"debug","z":"30af2d3e.d94ea2","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":810,"y":2040,"wires":[]}]
Set in smooth node to average every 3 readings. You will need to install the smooth node from the pallette.
Hope it helps.
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It is an area monitor which needs accurate temp. And when the temperature is getting high, I must know it quickly.
Is it really worth doing the averaging? Is there a lot of noise in the signal so you need to average it? Otherwise sample at whatever rate you need for your real time monitoring and then just send one every 5 mins (or whatever is appropriate) to the database.
Hi, thanks.
I don't really need that much information. But at first, these data were sent through rs485 devices where I could not change the sampling rate. I was thinking that average is the simplest way to slow down data transfers.
And at all, raw data looks like this:
{*072 4 411.8 20.28 8351 240.1 33.04 7905 46 10870
11} - {id status dcvoltage dccurrent dcpower acvoltage accurrent acpower temperature todayPower humidity} pressure don't need|
I use function to split data into something that I can analyze, then wait with data for at least 1 min and then send it as is to SQL server
To slow down the data transfers then use a Delay node in rate limit mode, with discard intermediate messages set.
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Thanks it works well
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