ESPHome / Home Assistant

ESP32 Smoker Controller

ESP32-S3 with PID control, adaptive power limiting and damper control

ESP32-S3ESPHomeHome AssistantPID-ReglerDS18B20PT1000BME280PZEM-004TModbusServo

Description

Fully automatic smoker controller based on an ESP32-S3-N16R8 running ESPHome. A PID controller drives the heater via PWM to an SSR relay and keeps the chamber temperature precisely at the setpoint. Two DS18B20 sensors at the top and bottom of the chamber provide the input values, which are combined into a weighted average for the PID loop. A BME280 on the outside of the cabinet measures ambient temperature and humidity, which feeds into the heat-loss model. A separate PT1000 via MAX31865 is mounted on the outside of a stainless-steel cold smoke generator, right at the burn zone — the measured temperature there is used to regulate the generator's air pump so the chips smoulder cleanly without overheating. An adaptive power limiter calculates the maximum permissible heating power every 30 seconds based on ambient temperature, setpoint and computed heat loss — effectively preventing overshoot above the setpoint. A stable-state detector running every 5 minutes adapts the heat-loss coefficient; depending on the detected operating regime, different PID parameter sets (hot/cold) are switched in. An MS24 servo (270°) drives the exhaust damper, a PZEM-004T v4.0 over Modbus measures voltage/current/power/energy. The whole system integrates into Home Assistant via native ESPHome entities: Climate, Sensor, Number, Switch, Button.

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I deliver software only (firmware, configuration, code) — no assembled hardware. The components used are only linked for reference, you buy them yourself. Enclosures on request.

Features

PID temperature control with deadband
Adaptive max-power calculation from heat-loss model
Automatic switching between "hot" and "cold" PID parameter sets
Multiple sensors: 2x DS18B20 (chamber), PT1000 via MAX31865 (smoke generator), BME280 (ambient climate)
Servo-controlled exhaust damper (MS24, 270°)
Energy monitoring via PZEM-004T v4.0 over Modbus
Home Assistant climate entity, natively integrated
Safe boot sequence: control OFF, fan 0%, damper closed

Techstack

Hardware

ESP32-S3-N16R8
DS18B20 (x2)
BME280
PT1000 + MAX31865
PZEM-004T v4.0
MS24 Servo 270°
SSR-40DA
Heizelement

Software

ESPHome
PID Climate
One-Wire / SPI / UART-Modbus
Lambda-Automationen

Integration

Home Assistant Native
ESPHome Dashboard
MQTT optional

Code snippets

PID controller with deadbandyaml

climate:
  - platform: pid
    id: pid_controller
    name: "PID Temperatur-Regelung"
    sensor: temp_garraum_mittel
    default_target_temperature: 25°C
    heat_output: heizung_pwm

    control_parameters:
      kp: 0.12
      ki: 0.0008
      kd: 1.0
      output_averaging_samples: 5
      derivative_averaging_samples: 5
      min_integral: -0.3
      max_integral: 0.3

    deadband_parameters:
      threshold_high: 0.3°C
      threshold_low: -0.3°C
      kp_multiplier: 0.0
      ki_multiplier: 0.0
      kd_multiplier: 0.0
      deadband_output_averaging_samples: 15

    visual:
      min_temperature: 15°C
      max_temperature: 120°C
      temperature_step: 0.5°C

Adaptive max-power limiteryaml

interval:
  - interval: 30s
    then:
      - lambda: |-
          if (!id(auto_start_enabled)) return;
          if (!id(temp_garraum_mittel).has_state()) return;
          if (!id(temp_aussen).has_state()) return;

          float temp_ist  = id(temp_garraum_mittel).state;
          float temp_soll = id(pid_controller).target_temperature;
          float temp_aus  = id(temp_aussen).state;

          float delta_T          = temp_soll - temp_aus;
          float heat_loss_watts  = id(heat_loss_coefficient) * delta_T;
          float error_abs        = abs(temp_ist - temp_soll);
          float max_power        = 0.15;

          if      (error_abs > 5.0) max_power = 1.00;
          else if (error_abs > 2.0) max_power = 0.50;
          else if (error_abs > 1.0) max_power = 0.30;
          else {
            float base_power = heat_loss_watts / 2000.0;
            max_power = clamp(base_power * 1.5f, 0.10f, 0.30f);
          }

          id(calculated_max_power) = max_power;
          id(max_heater_power)     = max_power;