Sensor Definitions¶
Once added to Home Assistant you can configure different settings for your PLT-1. Use the tabs below to see what each entity does, grouped the same way Home Assistant displays them.
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| Control | What it does |
|---|---|
| RGB Light | One RGB Neopixel LED. Click the light bulb or color wheel to change the color. Use the toggle to turn it on or off. Useful for visual plant-health alerts (for example, green when fine, red when soil is too dry). |
| Sensor | Default Update | Details |
|---|---|---|
| Soil Moisture | 60s | Water content of the soil as a percentage, calculated from the soil voltage against the 100% Water Voltage and Dry Voltage calibration values. Ideal range depends on the plant. |
| Soil Temperature | 60s | Reading from the optional DS18B20 soil temperature probe. Shows Unknown if no probe is connected. |
| Air Temperature | 60s | Air temperature around the plant from the AHT20 sensor. Adjusted by the Air Temperature Offset. |
| Air Humidity | 60s | Relative humidity of the air around the plant from the AHT20 sensor. Adjusted by the Air Humidity Offset. |
| LTR390 Light | 60s* | Ambient light level in lux. Polls at the LTR390 Update Interval* (60s by default). |
| LTR390 UV Index | 60s* | UV index measured by the LTR390. Polls at the LTR390 Update Interval*. |
| Soil ADC | 5s | Raw soil voltage from the ADC, used to calculate Soil Moisture. Diagnostic, disabled by default. |
| Setting | Default | What it does |
|---|---|---|
| ESP Reboot | — | Restarts the device. Helpful for troubleshooting or refreshing the connection. |
| 100% Water Voltage | 1.55 | Soil voltage that corresponds to fully saturated (wet) soil. Lowers the Soil Moisture scale. Tune this for your plant and probe. |
| Dry Voltage | 2.7 | Soil voltage that corresponds to completely dry soil. Sets the point where Soil Moisture reads 0%. |
| Air Temperature Offset | 0.0 °C | Calibration offset applied to the Air Temperature reading. |
| Air Humidity Offset | 0 % | Calibration offset applied to the Air Humidity reading. |
| LTR390 Update Interval | 60 s | How often the LTR390 light and UV sensors poll (1 to 300 seconds). |
| Sleep Duration | 5 min | How long the PLT-1 deep-sleeps between readings when Prevent Sleep is off. |
| Prevent Sleep | On | Keeps the device awake instead of deep-sleeping, so it reports continuously. Turn it off to let the PLT-1 deep-sleep between readings for more accurate onboard AHT20 temperature and humidity. |
| Factory Reset ESP | — | Erases settings and returns the device to factory firmware defaults. Disabled by default. |
| Entity | Default Update | What it shows |
|---|---|---|
| Apollo Firmware Version | on boot | The Apollo firmware build installed on the device (for example, 26.3.2.1). |
| ESPHome Version | on boot | The ESPHome version the firmware was compiled with. |
| Firmware Update | — | Shows whether a firmware update is available. Click Update and it installs the next time the device wakes; the optional OTA helper overrides Prevent Sleep to keep the device awake on demand. Separate from the Apollo Firmware Version and ESPHome Version sensors. |
| IP Address | on connect | The device's IP address on your network. |
| Online | on change | Connection status of the device to Home Assistant. |
| RSSI | 60s | Wi-Fi signal strength in dBm. Values closer to 0 are stronger; a weak signal can affect reliability. |
| ESP Temperature | 60s | Internal temperature of the ESP32 chip. Runs warmer than the room because of the processor and Wi-Fi radio. |
| Uptime | 60s | How long the device has been running since its last reboot. |