Chapter 5 · ESP32 Sensors5 min

DHT22 Temperature/Humidity

Wire a DHT22 to your ESP32 and stream temperature & humidity to LVGL.

The pattern - same for any local sensor

ESP32 reads sensor

update_interval: 10s

on_value

fires with new reading

lvgl.label.update

push to widget

No Home Assistant needed - the sensor runs entirely on the ESP32. Works with both DHT11 and DHT22.

Design labels for temp + humidity

Place two Label widgets in the designer - one for temperature, one for humidity. Give them IDs like temp_lbl and hum_lbl. Set the default text to placeholder values so you can see them on the canvas.

LVGL Designer with temperature and humidity labels on the canvas

yamlYour labels (from the designer)

# Your LVGL widgets (from the designer)

lvgl:
  pages:
    - id: canvas_130
      bg_color: 0xFFFFFF
      pad_all: 0
      widgets:
        - label:
            id: temp_lbl
            x: -40
            y: -55
            align: CENTER
            text: "--.- °C"
            text_font: montserrat_28
        - label:
            id: hum_lbl
            x: -40
            y: 15
            align: CENTER
            text: "--.- %"
            text_font: montserrat_28

Wire the DHT11

We're using a DHT11 board module (3 pins). The pull-up resistor is built into the board - just three wires, no extra components.

DHT11 BoardESP32Notes

VCC3.3VBoard modules are usually 3.3V-safe

DATAGPIO22Pull-up built into the board - no extra resistor needed

GNDGND

DHT11 sensor board with three wires connected to an ESP32 development board

The DHT11 gives you two readings from one sensor - temperature and humidity. Each gets its own on_value trigger, so you can update different widgets independently. Using a DHT22? Just change model: DHT11 to model: DHT22 - everything else stays the same.

Add the sensor YAML

yamlDHT11 → labels

# Add at root level of your device YAML

sensor:
  - platform: dht
    pin: GPIO4
    model: DHT11
    update_interval: 10s
    temperature:
      id: room_temp
      name: "Room Temperature"
      on_value:
        then:
          - lvgl.label.update:
              id: temp_lbl
              text: !lambda |-
                return str_sprintf("%.1f °C", x).c_str();
    humidity:
      id: room_hum
      name: "Room Humidity"
      on_value:
        then:
          - lvgl.label.update:
              id: hum_lbl
              text: !lambda |-
                return str_sprintf("%.0f %%", x).c_str();

platform: dhtBuilt-in ESPHome DHT driver - no extra libraries needed

update_intervalHow often to read - 10s is responsive, 60s saves power

name:Also publishes to Home Assistant automatically - free dashboard tile

Update an arc alongside the label

yamlLabel + arc from humidity

# Update an arc alongside the label

sensor:
  - platform: dht
    pin: GPIO4
    model: DHT11
    update_interval: 10s
    humidity:
      id: room_hum
      on_value:
        then:
          - lvgl.label.update:
              id: hum_lbl
              text: !lambda 'return str_sprintf("%.0f %%", x).c_str();'
          - lvgl.arc.update:
              id: hum_arc
              value: !lambda 'return (int) x;'

Flash and breathe on it

Flash OTA. Wait 10 seconds for the first reading. Breathe on the sensor - humidity should jump.

Serial monitor output showing temperature and humidity readings from the DHT11 sensor

[D][dht:048]: Got temperature=24.0°C

[D][dht:048]: Got humidity=55.0%

[D][lvgl]: temp_lbl → "24.0 °C"

[D][lvgl]: hum_lbl → "55 %"

Checkpoint - Do the temperature and humidity labels update every 10 seconds?

If yes - you've got a live local sensor. The same on_value pattern works for any ESPHome sensor platform.

Yes - keep going Reads NaN or doesn't update