Building a custom controller board for our family's pomace boiler.
What the board will need to control:
- motor to get pomace into the fire (relay, according to light sensor and thermometer) - pin 7
- fan motor which blows air into the flame (speed controlled, according to light sensor and thermometer)
- motors bring water from the house (relay, controlled by termometer and requests in the house) - pin 8
- motor to bring pomace into pyramidal storage (relay, according to a light/fullness sensor to be installed)
- motor to crunch pomace and bring it to the larger storage (user-actioned, but must add a protection against stalling)
- heat gun turn on/off (maybe)
- Will need a clock as well
Sensors the board will have to process:
- Boiler temperature
- Temperature of the waters going through the house (sanitary hot water)
- Temperature inside the house *really a binary value provided by a thermostat inside the house)
- Waste gas temperature
- Flame light
- In the future:
- Fullness of pyramid storage
- Stalling of the motors (especially the pomace breaker)
Components Required:
- Arduino Mega [BOUGHT]
- Wifi Module [BOUGHT]
- 4 Line LCD [BOUGHT]
- Clock Module [BOUGHT]
- Relays Shield [BOUGHT]
- Battery for clock module [BOUGHT]
- 12V Power Supply for relay module [BOUGHT]
- I²C Module for Screen [BOUGHT]
- Male-Female, Male-Male, Female-Female jumper cables [BOUGHT]
- fio normal de arame [BOUGHT]
- 4 Additional Temperature sensors [BOUGHT]
- 4 4.7 Ohm resistors to use with temperatrure sensor [BOUGHT]
- 10K Ohm, 100K Ohm resistors [BOUGHT]
- Buttons of some sort [BOUGHT]
- ESP32 board for control logic (or keep Mega + adapt interface) [TO CONFIRM]
- VFD / Inverter (230V single-phase in -> 230V three-phase out), minimum 0.18 kW [TO BUY]
- 1-channel optocoupled relay module for VFD RUN/STOP command [TO BUY]
- MAX485 (RS485) module for ESP <-> VFD speed command (preferred), or PWM-to-0..10V module [TO BUY]
- Electrical enclosure, DIN rail, proper breaker/fuse, earth wiring for VFD/motor safety [TO BUY]
- Dimmer module [BOUGHT, not used for this fan motor]
- Flame sensor [BOUGHT, need a more heavy duty one]
- 6X (at least) Extension cords to use with relays/VFD wiring (boiler feeder, hot water pump, radiators pump, ashes feeder, fan motor, large feeder) https://www.amazon.es/Brennenstuhl-Alargo-europeo-3-m/dp/B004AQTFWY/ref=sr_1_6?__mk_es_ES=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=WNHPZ8I7D70B&keywords=alargadera+enchufe&qid=1641738516&sprefix=alargadera+enchuf%2Caps%2C187&sr=8-6
- SD Card Module and SD Card
Currenly missing to get system working:
- VFD integrated with Fan Control (RUN/STOP + speed setpoint)
- Temperature sensor from hot water
- Thermostat working (kind of optional)
- Connections with wires to motors
Interrupts
- Needed for menus
- Fan speed control via VFD communication (RS485 preferred) instead of AC dimmer interrupt
Web server should be able to:
- Show the present state of the boiler
- Provide controls for motors
- Using Blynk running on our VPS
Data Storage:
- Timestamp from clock
- Stored into SD card
Motor control:
- Fan motor label: 3-phase, 220 V Delta / 380 V Star, 0.09 kW, ~2800 RPM
- To control speed from ESP/Mega: use VFD (1
230V in -> 3230V out), motor wired in Delta (220 V) - Control interface: digital RUN/STOP + speed setpoint over RS485 (or analog 0..10 V)
- Keep software fan power percent (0-100), map that to VFD frequency command (for example 20-50 Hz)
Resources:
- Connect LCD and rtc clock simmultaneously https://create.arduino.cc/projecthub/Tishin/rtcds3231-with-1602-lcd-i2c-367cb6
- Connect several relays with a single wire https://create.arduino.cc/projecthub/Pedro52/arduino-with-neopixel-optocouplers-controlling-many-relays-5f2573
- Connect a thermostat to Arduino https://electronics.stackexchange.com/questions/60857/thermostat-connections-with-arduino
- Connect the temperature sensors https://lastminuteengineers.com/multiple-ds18b20-arduino-tutorial/
- (Legacy idea, not valid for this 3-phase motor) How to dim the Fan Motor: https://www.instructables.com/AC-Dimming-and-AC-Motor-Speed-Control-How-to-With-/
- How to setup the light detector (just a photoresistor): https://create.arduino.cc/projecthub/ccPegasus/photoresistor-brightness-sensor-db3110
- How to solder I²C module to LCD https://www.youtube.com/watch?v=jTqOqmjpMIQ
- https://mauser.pt/catalog/
- https://github.com/marcass/furnace_control
- https://www.instructables.com/Arduino-Pellet-Stove-Controller/
- https://www.youtube.com/watch?v=_Zg5DRCHWfk