• Sensor
Apollo Automation

PLT-1 Ultimate Plant Sensor For Home Assistant

$27.99
$27.99
Shipping calculated at checkout.

The PLT-1B does not include a battery or charger due to shipping constraints. Users will need to source their own rechargeable 18650 for the battery version and a charger. Battery life is estimated at 6 months based on a quality rechargeable 18650 and the default sleep / wake settings.

The PLT-1 is an indoor plant multisensor that measures soil moisture, air temperature, humidity, LUX, and UV. It also features an onboard piezo buzzer and addressable RGB LED. Soil temperature can be measured using the optional temperature probe add-on. The sensor comes in a battery (B) and non-battery version, with the non-battery version being significantly smaller.

The PLT-1 uses a capacitive soil moisture sensor, which offers much better accuracy and durability compared to resistive sensors. Additionally, the ground contact portion is protected with a conformal coating, ensuring longevity and resistance to environmental factors.

Good sources for batteries:

USA: https://imrbatteries.com/products/samsung-35e-18650-3500mah-8a-battery
EU: https://www.nkon.nl/

Version:
  • Automated Watering: With its capacitive soil moisture sensor, you can set up automations to water plants only when moisture levels drop below a certain threshold.
  • Optimizing Sunlight Exposure: Use the LUX and UV sensors to monitor light levels, ensuring your plants get the right amount of sunlight. Automate window shades or grow lights based on current light conditions.
  • Temperature & Humidity Management: Track air temperature and humidity with the AHT20-F sensor, adjusting indoor climate controls (like fans, heaters, or humidifiers) to maintain ideal growing conditions.
  • Soil Temperature Monitoring: Use the optional waterproof soil temperature probe to monitor and control soil warmth for temperature-sensitive plants, especially in colder months.
  • Visual & Audio Alerts: The RGB LED can be programmed for visual notifications, such as turning red when soil is dry or green when conditions are optimal. The piezo buzzer can alert you if immediate action is needed.
  • Assembled sensor with case
  • A card with getting started instructions, including links to our documentation, open-source code, CAD models, and support
  • Apollo sticker

We hope to build a community on our discord and continue delivering products the community wants. Our team will be there to help answer any questions, suggestions, or problems you might have. Join us here: link

Wiki for documentation: https://wiki.apolloautomation.cloud

Product Details

  • Capacitive Soil Moisture Sensor: Accurate and durable, perfect for monitoring plant hydration.
  • AHT20-F Air Temperature & Humidity Sensor: Dust-protected for reliable air condition tracking.
  • LTR390 UV & LUX Sensor: Measures light and UV exposure, ensuring optimal lighting for plants.
  • Optional DS18b20 Waterproof Soil Temperature Probe: Monitors soil temperature with precision (20 cm / 7.8 inches).
  • RGB LED: Customizable for notifications (e.g., watering alerts, light levels).
  • Piezo Buzzer: Provides audible alerts for important plant care events.
  • Battery and Non-Battery Versions: Flexible power options to suit different setups and needs.
  • Home Assistant Integration: Easily automate and monitor plant health through your smart home system.
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Customer Reviews

Based on 8 reviews
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Scott R.
No longer a plan murderer

I was once guilty of murder in the first degree. Yes, I’ve killed many plants—plantslaughter, if you will. But then I discovered the PLT-1 on the Smart Home Solver YouTube channel. Intrigued by Reed's glowing review, I decided to try one for myself, and everything he said was spot on.

The PLT-1 integrates seamlessly with Home Assistant, allowing me to create custom automations that remind me to water my plants. The built-in RGB LED is a lifesaver—it’s like my plants have their own status light! Beyond that, the wealth of telemetry provided by the device offers incredible insight into not just my plants’ needs but also the environmental conditions in my home.

I was so impressed with its performance that I ordered three more and now have them set up throughout my house. My plants are thriving, and I have peace of mind knowing I’ll never forget to care for them again. If you're a plant owner—especially a forgetful one—these devices are an absolute game-changer. Highly recommended!

B
Brent V.
Finally, a plant monitor that "just works"!

I've tried so many different plant monitor options over the years, I've lost count at this point. ALL of them were either "fiddly" in some form or other, or locked you into a proprietary ecosystem which would result in dependencies I couldn't live with.

This is the perfect balance between "plug and play" and true ownership of your own products/data.

Buy the USB powered version IMO - you can purchase a high quality "octopus" USB-C cable (I have some 1->4 units), a 2/3 port usbc wall plug, and power 8(+) monitors from a single outlet.

My one bit of feedback would be to allow these units to work in a hub/spoke method, where one could serve as a bluetooth proxy for the rest of them in order to limit the number of devices connected to your WiFi access points. If someone has 50 of these things, that's a lot if connection states to maintain... Especially when instead you could simply have 2-3 of them on your wifi and have the rest communicating through those 2-3 via bluetooth.

Can be done manually via espHome edits, but I'm too lazy at this point (... that'll probably change if ever it ends up becoming a problem I'm forced to address lol)

M
Mark V.
Should have bought the wired version REV

I am sure it is my fault but the monitoring is constant therefore the battery life is like a day or 2 at best, not ideal. Otherwise the connection to Home Assistant was easy, and the sensor information is wonderful. Will buy wired version next time unless I can figure this battery issue.

Update: Got an email from the Apollo staff with a suggestion to place the Prevent Sleep option to off, and now the battery life is what I was expecting. I changed my rating from 3 to 5 stars!

M
Michael N.
Performs well and will surely help my houseplants

I ordered 4 without the temp probes and they all arrived in good condition within a couple of days. The set up instructions were clear and I had readings from my 4 houseplants within an hour of unpacking the box. I do worry a bit about the open hole in the sensor, so I will water carefully. It will be a learning curve to understand how much water to add when they are dry, as there is of course a lag of about 1-2 minutes before the moisture level updates in Home Assistant. I suggest making the illuminance sensor at the end of a lead like the temp probes, because houseplants can often be in deep pots where the soil is well below the rim, so reporting the illuminance deep in a pot isn’t useful. Being able to clip the sensor within the foliage would provide a more meaningful measure of a plant’s light exposure during the day and allow me to better position if needed. But overall, I have high hope that this little device will help my plants and I’m glad to have them.

D
Dino K.
Capable and accurate

Capable and accurate sensor, i just wish it was watetproof

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