Hi guys,

Thought I'd share details of my solar powered floating pool temp sensor that I put together to get pool temp data into Home Assistant.

Hardware required (had to use multiple vendors):

• 1 x Solar Panel
• 1 x DF Robot Solar Power Manager
• 1 x LiPo Battery - for the price, I just went with quite a big one
• 1 x Wemos D1 or similar - to use the external WiFi antenna, you need to shift a tiny zero Ohm resistor so you may need to find someone who can do this for you if need be.
• 1 x 1K Resistor - you'll only be able to buy these in bulk, they're cheap and they're handy for LED projects 
• 1 x Submersible temperature sensor
• A few jumper wires
• 1 x short USB to micro USB cable: to power the ESP from the solar controller (optional, unless you want to use jumper wires)
• A few short pieces of wire to solder onto the solar panel to connect it to the solar power manager
• A few metal BB bullets for ballast
• A few silica gel things for good measure
• A Trip to your local hardware store for: Various PVC Pipes/PVC Weld/Epoxy/Silicone from your local hardware store or you can use this 3D print which someone on Reddit put together - I'm thinking of trying this given that the pool chemicals seem to be eating away at the adhesive that I've used to join the parts - the epoxy just peels off!

Schematic:

 

You'll then need to assemble the actual housing and seal it up really well. Add some metal BB's to get it to float nicely and consider tethering it to the side of the pool with some string (just prevents it from getting bashed around by the Kreepy).

I would also suggest covering the solar panel in some glad wrap or something similar to protect it - the pool chemicals destroyed one of mine after +-6 months.

Code:

Initial code to obtain the DS18B20's Unique Sensor Address from the log:

esphome:
  name: pooltempsensor
  platform: ESP8266
  board: d1_mini_pro

wifi:
  ssid: "Your SSID"
  password: "Yourwifipassword"

# Enable logging
logger:

# Enable Home Assistant API
api:
  password: "apipassword"

ota:
  password: "otapassword"
  
dallas:
  - pin: D4
    update_interval: 30s

Once you've got the unique address, you can update the code as follows with your unique sensor address below:

esphome:
  name: pooltempsensor
  platform: ESP8266
  board: d1_mini_pro

wifi:
  ssid: "Your SSID"
  password: "Yourwifipassword"

# Enable logging
logger:

# Enable Home Assistant API
api:
  password: "apipassword"

ota:
  password: "otapassword"
  
dallas:
  - pin: D4
    update_interval: 1s

# Individual sensors
sensor:
  - platform: dallas
    address: 0xa03c01f0965f0b28
    name: "Pool Temperature Sensor"

  - platform: wifi_signal
    name: "Pool Temperature Sensor WiFi Signal"
    update_interval: 60s

  - platform: adc
    pin: VCC
    id: "VCC"
    internal: true
    
  - platform: template
    name: "esp.2.battery_level"
    unit_of_measurement: '%'
    update_interval: 5s
    lambda: |-
      return ((id(VCC).state /3.70) * 100.00);
      
# Deep Sleep to save power
deep_sleep:
  run_duration: 60s
  sleep_duration: 60min
  id: deep_sleep_1

It runs for 1 minute (to ensure it connects to WiFi) and then goes into deep sleep for 1 hour: (This was in summer BTW :D)

Anyway, here 's some pics:

Feel free to make suggestions and please let me know if you have any questions.

Nice project. Thanks for sharing.

Nicely done, especially like the pictures of V1 V2 and V3... was the surface water temp giving false readings?  Did you add a brick or something heavy?

Love the solar solution! Those little solar panels are quite pricey for the amount of watts you get.

How long did you take to build this? 

Is this your first project? 

 

That's pretty neat  @Muttley nice works 🙂 

Would be super cool to add a PH & Chlorine levels as well.

Saw this online a while ago 

https://www.aliexpress.com/item/1005004941285841.html  

12 minutes ago, iiznh said:

Nicely done, especially like the pictures of V1 V2 and V3... was the surface water temp giving false readings?  Did you add a brick or something heavy?

Love the solar solution! Those little solar panels are quite pricey for the amount of watts you get.

How long did you take to build this? 

Is this your first project? 

 

Thanks for the feedback - the V1 & V2 versions didn't work- mainly due to buoyancy issues- hence the reason why I added in the longer "down pipe" that sits below the surface - this is where the metal BB's live.

After all the iterations- it didn't take long to build, maybe a few hours but it's quite simple to build once you have a plan regarding the actual device that's going to house everything.

This was my first dabble with ESP boards - I've since created a Jojo Tank Volume measurement system using a submersible pressure sensor - will share details of this is anyone is interested.

Also created a somewhat automated Jojo Tank valve system which automatically closes one valve and opens another depending on the load shedding state. This switches between Jojo Tank water and municipal water. Our new solar system has the Jojo Pump on the inverter so this system is not really necessary.

Plus a few other silly LED/OLED Screen projects but nothing too fancy....

 

8 minutes ago, Sc00bs said:

That's pretty neat  @Muttley nice works 🙂 

Would be super cool to add a PH & Chlorine levels as well.

Saw this online a while ago 

https://www.aliexpress.com/item/1005004941285841.html  

Thanks so much!

I considered add something like this but decided that it wasn't worth the effort/price.

There are quite a few HA communities who've done full on aquatic tank measuring systems.

9 minutes ago, Muttley said:

Thanks so much!

I considered add something like this but decided that it wasn't worth the effort/price.

There are quite a few HA communities who've done full on aquatic tank measuring systems.

Agreed, that is pretty expensive, there is a cheaper non pro version of that sensor available as well for about R500 

https://www.robotics.org.za/SEN0161?search=ph meter