Solar Soil Moisture Meter // Becky Stern


Hi, it’s Becky. Today we’re making a solar powered soil moisture
monitor. It uses an ESP8266 wifi microcontroller running
some low power Arduino code, and everything’s waterproof so it can be left outside. Let’s get started. You’ll need a solar battery charging board
and ESP8266 breakout such as the NodeMCU or Huzzah, as well as a soil sensor, battery,
power switch, some wire, and an enclosure to put your circuit inside. It’s important to create a solderless breadboard
prototype for projects like this, so you can make sure your sensor and code are working
before making any permanent connections. In this case, that meant temporarily attaching
solid headers to the stranded ends of the sensor wires. You can find the circuit diagram for the prototype
and the final version at the link in the description, and learn more about using Arduino on the
ESP8266 in my free Instructables Internet of Things Class. Prepare the solar charging board by soldering
on its capacitor and some wires to the load output pads. I’m customizing mine to charge at a faster
rate with an optional add-on resistor, and making it safer to leave unattended by replacing
the surface mount resistor with a 10K thermistor attached to the battery itself. This will limit charging to safe a temperature
range. Solder up the microcontroller board and power
switch to a perma-proto board, and connect the solar charger power output to the input
of your switch, which should be rated for at least 1 amp. Mark and drill holes in a waterproof enclosure
using a step drill, and install two cable glands, or waterproof clamps, basically. Insert the port side of a waterproof power
cable into one and solder it to the solar charger’s DC input. Insert the soil sensor through the other,
and connect it up to the perma-proto. Test it out before closing up the enclosure
and installing the sensor in your herb garden, precious potted plant, or other soil within
range of your wifi router. The program sleeps most of the time, but wakes
up occasionally to read the temperature and humidity of the soil, and reports it to the
cloud data service Adafruit IO. From there it’s easy to set up a recipe
for email or txt alerts on the API gateway site If This Than That. This is a fun project to customize. You could switch out the sensor for something
else entirely, or integrate the solar power features into your other Arduino projects. This project is part of my free Solar Class
on Instructables.com, where you learn more about harnessing the energy of the sun, from
advanced applications like this one to fun backyard activities too. I put a link in the description, and it would
mean so much to me if you’d check it out. Thanks so much for watching! Please subscribe new DIY videos every week
about technology, crafts, and my life here in New York City.

10 thoughts on “Solar Soil Moisture Meter // Becky Stern

  1. Interesting, but the Adafruit states the Sensor as suitable for weather sensing, not for soil sensing and in fact should not be used for more than an hour in a wet environment (such as soil?).
    Regardless…. A nice project

  2. cool beans, or bean sprouts as the case may be. We have a watering timer valve that waters automatically but a more efficent way would be to have those items talking is there a board for that? Orbit Digital Hose Water Timer its like one of these lowes sells them

  3. Fairly new to the diy electronics scene, so question; would it be feasible to create one solar panel/charger/battery enclosure that then powers multiple soil monitors?
    I'm attempting to find the cheapest, most efficient way to monitor about 8 vegetable planters.

  4. Woaoaoa! You are using quite much equipment for the job, return of investment cannot be expected after 30 years harvesting ehm, succulents.

  5. Hello Becky. Great video. I am working on a project which has similar functions like this. I have to use Zigbee and ESP8266 together and create a demonstration. Is it possible to interface both? What will be the good choice between ESP8266 and NodeMCU to connect with Zigbee? I would appreciate your guidance and expertise on the same for explaining connecting Zigbee and ESP8266/NodeMCU.

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