Hi, Im trying to control the level in a tank with node red on the raspberry pi 3. I have a low and high switch at the bottem and top of the tank and a solenooid to let in water. Im very new to coding and node red so i need some help. Ive done up a flow (I know its ugly) and it kind of works but, if…

OK when you say the switch is stuck - i assume you mean the "Virtual" switch i.e. your variables you are using - rather than the physical switch being faulty ? (if it is the physical switch then you need to get that replaced, not try to code around edge use cases). I will assume that once you recei…

Later on if you want to get fancy - you can look at doing this as a Finite State Machine - using the DSM node (And i can not import your flow either) when pasting a flow - select the nodes and then choose the export option When you go to paste them in here then put 3 backticks on a single line (by…

[{"id":"8757536f.2115c8","type":"rpi-gpio in","z":"e4167a44.5763d8","name":"Low Level SW","pin":"40","intype":"up","debounce":"25","read":true,"x":150,"y":720,"wires":[["e0876d8c.a7238"]]},{"id":"ca05192d.5c77b8","type":"rpi-gpio in","z":"e4167a44.5763d8","name":"High level SW","pin":"38","intype":"…

Maybe i could try somthing like this but i dont know how assign the variables from the 2 switches, [{"id":"abfdc92b.0f7be8","type":"rpi-gpio in","z":"e4167a44.5763d8","name":"Low Level SW","pin":"40","intype":"up","debounce":"25","read":true,"x":510,"y":1100,"wires":[["c7cf5cde.303d3"]]},{"id":"d39…

Use the Change Node which can take an input value in the message body (payload) and put it into a context variable I am not at my computer to do a flow now - but if you follow the logic from what i said above you should be able to get a solution Craig

[image] Jez: [{"id":"abfdc92b.0f7be8","type":"rpi-gpio in","z":"e4167a44.5763d8","name":"Low Level SW","pin":"40","intype":"up","debounce":"25","read":true,"x":510,"y":1100,"wires":[["c7cf5cde.303d3"]]},{"id":"d398d6cb.dc6c5","type":"rpi-gpio in","z":"e4167a44.5763d8","name":"High level SW","pin…

OK Try this [{"id":"c78f696.b5cee98","type":"rpi-gpio in","z":"b68d15f7.6a1ab8","name":"Low Level SW","pin":"40","intype":"up","debounce":"25","read":true,"x":210,"y":440,"wires":[["a3253f5a.7b082"]]},{"id":"427da720.c44318","type":"change","z":"b68d15f7.6a1ab8","name":"Set Global Variable to fill …

I have a flow I was using in my son's greenhouse (the bum moved!) I had a hydroponics setup and the water tank had two float valves, one at the top and one halfway down. They were tied to two gpio pins on the pi - if the switch was up, it would report 'high', if it was low it would report low. Both …

Hi craig, Thanks for the help so far, I kind of understand about to concept of storing a variable but i dont really understand what i am meant to do with these nodes in your flow. Here is picture of what i would do if i were to hard wire it. [26%20am] Hi Zenofmud, Could you please export your …

Yep you are getting hardware and software mixed up and making it harder than you need to. The nodes in my flow are to simply read the state of the input pins on the Rpi, based on them you set the global variable appopriately. Think about it this way - once the tank goes low you want to know that f…

Help controlling water tank level

General

craigcurtin 24 June 2019 20:51 21

Yep thats essentially what i have given him with the flow that i posted above.

The safety element is nice and simple also - could obviously be further enhanced with another sensor (i personally use a waterproof ultrasonic sensor on my tank) to control the levels.

Craig

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Help controlling water tank level

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