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The SparkFun Soil Moisture Sensor is a simple breakout for measuring the moisture in soil and similar materials. The soil moisture sensor is pretty straight forward to use. The two large exposed pads function as probes for the sensor, together acting as a variable resistor. The more water that is in the soil means the better the conductivity between the pads will be and will result in a lower resistance, and a higher SIG out.
To get the SparkFun Soil Moisture Sensor functioning all you will need is to connect the VCC and GND pins to your Arduino-based device (or compatible development board) and you will receive a SIG out which will depend on the amount of water in the soil. One commonly known issue with soil moisture senors is their short lifespan when exposed to a moist environment. To combat this, we’ve had the PCB coated in Gold Finishing (ENIG or Electroless Nickel Immersion Gold). We recommend either a simple 3-pin screw pin terminal or a 3-pin jumper wire assembly (both can be found in the Recommended Products section below) to be soldered onto the sensor for easy wiring.
Note: Check the Hookup Guide below for assembly and weatherproofing instructions as well as a simple example project that you can put to together yourself!
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Skill Level: Noob - Some basic soldering is required, but it is limited to a just a few pins, basic through-hole soldering, and couple (if any) polarized components. A basic soldering iron is all you should need.
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Skill Level: Rookie - You will need a better fundamental understand of what code is, and how it works. You will be using beginner-level software and development tools like Arduino. You will be dealing directly with code, but numerous examples and libraries are available. Sensors or shields will communicate with serial or TTL.
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Based on 14 ratings:
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We can integrate it with our PLC or another circuit for our project . It is easy to use with or without an arduino board. The only thing we need now is something like this to use as a PH sensor :)
1 of 1 found this helpful:
It was easy to get it setup and configured. I'm working on solar power and bluetooth le for it, for some outdoor planters I'd like to keep an eye on. A fun little project to hack on!
Only 5 minutes after unpacking I had the sensor set up in soil and was running a barebones program to display the reading on the serial plotter. Easy for beginners and a great sensor to try things out on the Arduino.
With your tutorial it says that both the sensor and the LCD light should be connected to the 5 volt input. The tutorial doesn't give us an idea of how the LCD should be connected with the RedBoard along with the sensor. If you guys can explain how to connect everything, that would be helpful.
Hey sorry to hear about the difficulty with the LCD. It is a little tricky of us not to show the pin connections I agree.
If you're looking for a quick solution though, you can look at the code real quick on the LCD, where it declares which pins are connected to the LCD: // Attach the serial display's RX line to digital pin 2 SoftwareSerial mySerial(3,2); // pin 2 = TX, pin 3 = RX (unused)
That, and making sure that the device has power and common ground would be what you need to do to hookup the LCD in the setup.
Hope that helps!
Like the fact that the reading is zero when there is no water but goes the reading goes 800+ when dipped in water. Wish Sparkfun also sold three post terminals that can be soldered to the moisture sensors.
Easy to wire and use, super sensible to humidity, even if you touch it, but you just set the threshold and you'll be ok!
soldered a few wires on and it worked like a charm connected to and A/D then to a RasPi for a Smart Gardening Project.
It is stable. But when I wait 3 sec. after activating the sensor it gives considerably lower readings. Best regards torben
I put the leads in the soil because I assumed a soil moisture sensor is designed to measure the soil moisture. Stupid me, every child knows electronics dont work very well in moisture. I was getting very inconsistent readings going lower and lower until finally it stopped giving me any read. I pulled it our of the ground and I found out that one lead corroded and wore off leaving just the PCB plastic. That was within 2 months and most of my readings was garbage as I could not correlate them throughout the weeks. I am using another one for just water detection and no soil but Im afraid it will also corrode.
Hello, and sorry to hear you're having trouble. Send us an email to firstname.lastname@example.org and we can help you with this issue.
I have had two moisture sensors in the ground for about three weeks and they have performed without any signs of degradation. Be sure to moisture proof the top portion of the the probe to prevent corrosion buildup. Excellent product.
I bought two of these, and they worked great out of the box! Also, until I read the hookup guide, I'd had no idea how easy it is to apply conformal coat. It's quite easy.
One side note: I tested these things out by hooking them up to an ADC board (https://www.adafruit.com/product/1083) and comparing the dry reading against the reading from shorting together the two electrodes. At first, I had a software bug, which made me think that one was giving me a very different reading than the other. But since I soldered wires directly to the board, then applied conformal coat prior to testing them, it's hard to check if it's just a bad solder joint, or if one of the resistors is populated differently, or what. In the end, I found the software bug, so it wasn't a big deal.
So my recommendation is: 1) buy these if you need them, and 2) check your work with a multimeter BEFORE applying conformal coat. It'll save you some questioning later.
I'm using these for an automatic plant watering project, and am posting source files and designs here: https://github.com/jwalthour/GreenThumb I hope this helps someone!
See at https://github.com/OlivierLD/raspberry-coffee/blob/master/Project.Trunk/PlantWateringSystem/README.md (bottom of the page)
I am using this device to monitor the moisture content of my work farm. I can log in remotely and get status. Works great.
Having the chip right on the sensor is handy for protoyping w/o extra wires/boards