Sort of new to the Pi, making a Hot Tub Controller

[Hdale85]

Ok so I've done a little with the Pi, and I've used linux some in the past but I figured this was still the better spot to post as I don't consider myself an advanced user. I bought an Intex Inflatable Hot Tub that was broken, giving error code 96 which is all over the internet and seems to just be some sort of fault with the controller itself. So I'm trying to build a new controller based on the Pi.

I found this project
http://www.instructables.com/id/Hottub- ... Interface/

Which I think will work just fine. There are some things I'm not sure about though.

I'd really like to use the built in sensors, it has 2 temp sensors and then a third sensors that is used for overload protection of the heater unit. They all use 2 wires. On one of the normal temp sensors I see numbers written 1606, The other one had a 54 but that's about all I could make out. They look just like normal temp probes, I can take pics if needed.

After that there are 2 flow sensors they have MKA14103 on them. Again just 2 wires on these.

The last thing is there is some sort of descaling system, on the PCB it just had SCALE and SCALE +, I followed the wire and it's literally just the same wire wrapped around the hose of the water output jet in 2 layers. So some sort of powered coil that's supposed to aide in descaling? I'm not sure if I can make this work with the RaspPi or not? lol

Everything else is pretty straight forward, the water pump has a transformer onboard that converts 120vac to 12vac 60hz, which also feed a rectifier so there is 12vdc available. The bubble motor is 120vac, as are the 2 heaters.

I was hoping to use an RaspPi Zero W and a relay board from amazon, which the relays are rated for 120v 15amps each. The entire unit was rated for 120v 12amps before so I think that should be fine. I just need some guidance on whether these sensors will work or what I can replace them with but keep the same stock locations and such for ease of conversion. I can snap pics of any of the sensors if you like, although the flow sensors are just little black sticks. Either way thanks for any help, I spent about 1.5 hours tearing the whole thing down tonight and tracing all the connections and jotting down what went where.

[B.Goode]

Welcome to the Raspberry Pi forums.

You don't say anything about your training and experience, so the following might be inappropriate for you personally but may apply to others reading this in the future:

Mixing Human Beings, Mains Electricity, and Water is potentially life-threatening - if you do not have the right training and background you should probably not be undertaking this modification.

After the conscience-clearing Net Nanny warning, a factual response -

I just need some guidance on whether these sensors will work

Temperature sensors with just 2 wires are probably, but not definitely, analogue devices. An RPi has no built-in analogue capabilities: you will need an external analogue-to-digital convertor (ADC). (That may be why you have already included an Arduino in the design?)

[Hdale85]

I was tired last night when typing out that post and miss spoke lol.

So I'd probably need something like the Pimoroni Explorer pHAT for analog inputs and such. At least if I end up using the pi zero. I have an older pi b v2.1 that I could use although no idea if it still works as it's been sitting in a box for a while.

Or maybe it would be better to try and get digital sensors that would work instead. Just not sure if I can get any that'll fit the stock locations.

It appears the flow sensors may be magnetic reed switches, I need to look at the setup again because I didn't see any magnets.

[Hdale85]

Do you think this would be overkill?

https://pi-plates.com/daqcr1/

Or maybe this would be enough

https://www.abelectronics.co.uk/p/69/ad ... -converter
can't find a distributor that has it in stock in the states though.

I do need this to be simple to put together, wiring connections and such I'm fine with, but writing code is not something I'm familiar with lol.

[Hdale85]

Ok, never mind again I finally found one located state side.

https://www.robotshop.com/en/8-channel- ... -zero.html

So if all I need are analog inputs then this may be the simplest solution.

[Hdale85]

Ok, so I decided to use the PI I have (long as it works anyways lol, and grab one of these

https://www.amazon.com/gp/product/B01DL ... LMXA&psc=1

Along with the 4 channel relay board. That should work pretty decently right? Hopefully I don't have to alter to much since I'll be using some analog inputs. There is an Arduino project for hot tub control but the website appears to be dead for some reason.

[openpid]

@Hdale85: Did you complete this project? Can you share any details?