- Battery powered ORP, pH sensor for Hot Tub/SPA
- ~ 1 year battery life @ 2 samples per hour
- Sensor externally mounted, probes placed under the skimmer cover
- Home Assistant Integration
- pH ATC (Automatic Temperature Compensation) integrating with Balboa temperature sensor
- Free Chlorine/Bromine estimate model from PH and ORP values
- UM FeatherS2 ESP32 board from here
- 3500 mAh battery or 2500 mAh
- Atlas Scientific Gravity Analog ORP and pH Kits
- Enclosure: DS-AT-0811-S
- 2x100 kΩ resistors for battery monitoring (optional)
- micropython. OTA & Logging over MQTT
- deep (50µA) & light (7mA) sleep
- Build instructions
- Code
Predict Free Chlorine & Bromine ppm from pH and ORP sensors.
- Data source: https://jenfitch.com/free-chlorine-orpmv-vs-ph-new/
Build the model: build_model.py.
Prebuilt models:
-
model_fc.h5: model for predicting FC from ORP/pH
-
model_orp.h5: model for predicting ORP from FC/PH. This one can be used to calibrate your ORP sensor by getting your water lab tested
Basic script to load and run these models. usage:
python3 ./predict.py model_fc.h5 666 7.6
-> output: 0.83490694
./predict.py model_orp.h5 7.6 0.85
-> output: 667.04565