Generally, a finite state machine that runs on ESP microcontrollers.
Control a sauna with ESP8266, PID (1-wire Dallas temperature sensors), web server.
Interface makes it easy to program temperature profiles (on another host, over HTTP), so sauna can also be an oven, a drying rig, refrigeration unit, or any other similar climate-controled device. Focus is on clean and versatile code.
- PID-based temperature control
- remotely enable/disable device
- remotely set temperature target
- low-latency UI updates (websocket) ; works well with multiple clients
- CLI prototype (python) for easy scripting
- independant phase control, code mostly supports configurable number of outputs
- staged proportional heating (SSR on slow PWM) or (slower still) staged control of electromechanical relays
- door switch support and client-side timer (with auto-start)
- optional PS-VM-RD integration (voltage measure)
- ESP starts in AP mode if SSID is not configured, or if connection to configured SSID fails after configured timeout
In no particular order...
- HTTPS on ESP32
- RGB lighting (connect to WLED host?)
- ice bath
- Timing bell and deadman's switch
- Max power setting for controlled temperature slopes
- some sort of authentication mechanism
- HTML form to set parameters
- make HTML (and js and css) support configured number of relays
- temperature graph in HTML UI (host-side temperature history)
- TRIAC output
- PS-VM-RD temperature and relays
- bar-graph style power output for SSR and TRIAC widgets
- autocloud integration
A few more TODOs reside in the code ; just grep it.
It is advised to use a certified, external protection such as the Danfoss KP85 (060L125666) thermostat: trip point set slightly above the max operating temperature, NO SELF RESET / MANUAL RESET ONLY.
In any case, the author does not endorse ANY responsibility in case of malfunction, fire, injury or whatsoever : YOU ARE ON YOUR OWN, and NEVER LEAVE A POWERED DEVICE UNATTENDED.
This is valid for ESP8266 ; for more advanced features (ie. PS-VM-RD support, ESP32 is recommended)
ESP label PS-VM-RD
--------------------------
D0 WS2812_Din -
D1 OneWire - // temperature sensors
D2 RAON 7
D3 RELAY1 -
D4 DOOR_SW -
D5 SCLK 15
D6 (MISO) SDO 14
D7 (MOSI) SDI 13
D8 (CS) LATCH 16
RX RELAY2 -
TX RELAY3 -
A0 AOUTA 12 // for PS-VM-RD
Copy src/network.h.example and save your changes in src/network.h. Check configuration options in src/main.cpp. Then:
pio run --target uploadfs
pio run --target upload
pio device monitorcurl http://<ip>/enable
curl http://<ip>/disable
curl http://<ip>/set?target=<float temperature>