Anyone who owns their own pool knows it’s not as simple as filling it up with water and jumping in whenever you want. There’s pool covers to deal with, regular cleaning with the pool vacuum and skimmers, and of course, all of the chemicals that have to be added to keep the water safe. While there are automatic vacuums, there aren’t a whole lot of options for automating the pool chemicals. [Clément] decided to tackle this problem, eliminating one more task from the maintenance of his home. (Google Translate from French.)
The problem isn’t as simple as adding a set amount of chemicals at a predetermined time. The amount of chemicals that a pool owner has to add are dependent on the properties of the water, and the amount of time that’s elapsed since the previous chemical treatment, and the number of people who have been using the water, and whether or not the pool cover is in use. To manage all of this, [Clément] used an ORP/Redox probe and a pH probe, and installed both in the filtration system. The two probes are wired to an Arduino with an ethernet shield. The Arduino controls electrically actuated chemical delivery systems that apply the required amount of chemicals to the pool, keeping it at a nice, healthy balance.
[Clément] has all of the Arduino code available on his project page, as well as information about all of the various sensors he used. This should make this project re-createable for anyone who is tired of dealing with their own pool or paying a pool maintenance company to do it for them. [Clément] is no stranger to home automation projects, either, and we look forward to his next (often unconventional) project to automate something we might not have thought of before.
Home pool controls are a great IOT opportunity as pool controls are often hidden away. I am working on a system that retrofits a salt water system using a PSOC device with an ESP8266 and integrates with my home hvac system for freeze control. BTW devices like the Cypress 4200 are great when you need to combine analog and digital as I had to do for the retrofit.
I recently put in service the 2nd generation of my ESP8266-based system. It has 1-wire ds18b20 temp sensors for the pool, solar heater, control-box, and hopefully soon ambient-air temps, and relay (SSR) outputs for the pump, saltwater generator (not working this time around, maybe relay fried?), and solar heater pump. I want to add an ORP sensor into the mix so I can PID the runtime of the saltwater generator. It’s using MQTT to io.adafruit.com for control right now, but I’ll be working on getting it all running locally on the Pogoplug that’s going to be doing similar things to my HVAC system shortly (boards at oshpark, damper->servo bracket printing out right now).
The is what I like about the modern technology eco system.
From the pic is seems that the project creator doesn’t have a lot of experience with soldering and yet today this is no barrier to someone making a complex project like this. Once upon a decade, only an experienced technician or engineer would even attempt this.
Excellent project and well done!
To be fair he is probably using lead free solder. I tried that once and then through it in the bin.
“there aren’t a whole lot of options for automating the pool chemicals”
Err any owner of a salt chlorinator would disagree, and that’s 20% of pool owners.
I have a chlorinator and it needs maintenance every 3 months or so. But that is not the problem.
The problem is the amount of chlorine it needs to produce varies greatly depending on temperature and amount of human use of the pool. In other words, I am continually measuring FCL and TCL of the pool.
I also have to measure PH regularly as well as total Alkalinity.
Any project that makes the reporting of FCL, TCL, Ph and Total Alkalinity continual, will be worth a read.
It’s not automating the dispensing that is important, it is continuous data collection that is useful.
How can he permanently use those Redox and PH sensor without corroding it? They are meant to be enclosed in neutral solution to prevent oxidizing/corroding. I bet those sensors won’t gonna last long not to mention the accuracy over time.
I am a pool owner too, and I used chlorine and PH- over a decade. It is very likely that all those chlorine is a smart marketing trick, because it vaporizes over time and you have to buy it again and again. Over the last 5 years I have discovered a better working solution. When the pool is filled with water you will only need chlorine once for disinfection. Then you just need to add 1.5g CuSO4 · 5 H2O (copper(II) sulfate penta hydrate) and 3g (NH4)2SO4 (ammonium sulfate) for every 1000l (1m³) water! It will not vaporize over time. And even better it will not smell. LD50 is 300 mg/kg body mass (rat). I doubt you can drink that much. From now on you never have algae again. For disinfection you can also use CDS (chlorine dioxide solution) which is used for drinking water purification which is much more effective than pure chlorine.
http://www.broadleyjames.com/product/model-d2551c-pba/
Since they describe this as being a Pool & Spa Redox sensor and described as “long lasting”, I strongly suspect that there’s non-lab-grade sensors (which is what you’re talking to) that last a bit under this use. Yeah, he’d have to replace it, but if it’s a seasonal replacement, the realtime tracking of things would be epic. I’d love to manage a system where the chlorination was better managed as well as the PH and alkalinity if possible.
I wondered if there were good sensors. Now I know. >;-D
We have a board (http://iothyngs.com/?p=203) that is purpose built for this kind of automation. I’ve got mine configured for pool automation, but it can be used in countless other monitoring and control applications.
I currently do not have the Chlorine and pH sensors plumbed in, so this article is very interesting to me.
I use that same board for my pool! I’m running ESPEasy firmware. That firmware makes life very easy to set up IoT modules. I currently am monitoring Air Temp, Water Temp, Filter pressure, Pump on/off state and Jbox internal temp. I also record uptime and wifi strength. ESPEasy allows me to connect to my ThingSpeak account directly but using a Raspberry Pi I can use NodeRed to direct the data to both Thingspeak and my OpenHab setup.
I use the rest of the relay outputs for controlling landscape lighting. I also want to look at sensors for PH and Chlorine. I haven’t figured the best way to do it yet. I am also working on a way to use the ESPEverything board to control my Chlorine generation (I have a salt water pool). My Jandy Chlorine generator sucks and spare parts are hideously expensive. If I can mimic some of the functions of the Jandy with the 885 board then I can get rid of the Jandy altogether. Chlorine generation is just switching low voltage high current to the generator cell and reversing the DC polarity occasionally. This board could do that easily.
I used to run a pool for a hotel, it uses an automatic chlorinator with ph control, and I can tell you for sure that someone makes a sensor that can last years. Both the ph and ORP sensors last forever…. or at least a very long time.
I got a pool this summer install and was looking for some sort of automation on it too.
I mostly trust the average setting of the salt machine and see the chlorine level looks ok.
What I would be more prone to add would be a water leveling: we got so much rain one day that I had to go out and drain some 2 times!!!
And other days, the water evaporated so much lost almost an inch in a day!
Phase 1: a warning system thru email
Phase 2: water level adjustment to add or drain by itself
Alex, Look into nagios. It is meant for network monitoring, but you can create plugins to monitor pretty much anything. You can also program it to run programs or perform actions when events happen. I have a wemo on my livingroom air conditioner and i had it set up to keep an eye on outdoor temps via one of the weather websites. When the outside temp was over 70F, nagios would turn the wemo on. Since I first set it up, i built a few wifi thermostats. Now nagios monitors the temps of my freezers, livingroom (and controls the AC), and my office.
If you install nagios, also install nagiosgraph. it does exactly what it sounds like.