Garden sensors measure soil moisture and greenhouse temperature

[Andy] is getting his garden up and running. This year it’s been pretty cold so he decided to get small plastic domed tunnel which acts as a mini greenhouse. To help monitor that environment he built this sensor array which displays temperature and soil moisture readings.

Temperature is quite simple. He’s using a TMP36 sensor which is held a few inches above the soil. The moisture sensor is of his own design. It uses two building screws embedded in foam. These are pushed into the soil and a resistance reading indicates moisture level. By driving voltage on one screw, and measuring voltage on the other he gets some useful data. It’s not a standardized value, but observation over time will let him know how the scale relates to dry or wet soil.

During the build process he found that he needed a pull-down resistor on the probe used to take the moisture measurement. He also uses an I/O pin to drive the other screw. This gives him a way to shut off the juice when not taking a reading. We just hope he’s either got a current limiting resistor, or is using a transistor to drive it high.

Boost your garden’s output using ultrasonic mist

ultrasonic_aeroponic_growing_rig

If you enjoy gardening, it’s never too early to start thinking about next year’s growing season. [Jared Bouck] over at InventGeek loves his tomatoes, but the slow grow rates of his dirt-bound plants were less than impressive. To get things moving faster, he created a low-cost aeroponics system that uses ultrasonic mist to produce some pretty impressive results.

The construction process of this ultrasonic aeroponics rig looks dead simple, and [Jared] said that he had everything assembled in about half an hour. A cheap ultrasonic mister was mounted in the bottom of a plastic tub, and holes were cut in the tub’s lid to make room for his growing baskets. Tomato seedlings were wrapped in rock wool and placed in a clay growing medium, suspended over the water bath. The mister was turned on, and after just a few days, the results were obvious.

In the last step of his tutorial, he compares his aeroponically grown plant to one grown in soil – the difference is unbelievable. Considering how reasonably priced his setup is, it seems like a no-brainer to start growing your entire vegetable garden this way.

Moisture control for a DIY greenhouse

greenhouse_moisture_controller

[Clover] loves plant biology, and tends a small garden while she is at home during breaks from college. She says that her family is notoriously unreliable when it comes to caring for plants, so she decided to construct a greenhouse to ensure that her garden will still be around the next time she comes home.

With her raised bed garden built and her seeds planted, she started work on the greenhouse itself, which was constructed using PVC pipe and clear plastic sheeting. Satisfied with how the structure came out, she focused on the greenhouse’s watering system and moisture sensors. The watering system uses solenoids that are connected to a pair of Arduino regulated relays. The Arduino uses moisture sensors constructed from nails, triggering the water flow when things get too dry.

The controller along with its LCD status panel was mounted inside a bird house to protect it from the elements while keeping in line with the house’s decor. [Clover] seems pretty happy with the build, but we suspect she will be adding some temperature and regulation at some point, to facilitate longer growing cycles.

Check out the video below for a quick tour of her setup.

Continue reading “Moisture control for a DIY greenhouse”

Grow box controls heater, fans, and water

grow_box_controller

The Cheap Vegetable Gardner wanted more automation than their previous PS2 controller based grow system. This time they set out to design a full featured, compact grow controller that can measure temperature and humidity as well as control a heat lamp, fan, and water pump. An Arduino provides USB connectivity and interfaces the solid state relays and sensors. The assembled project all fits in a box but we are left wondering how much heat the four SSRs generate and will it be a problem?

[Thanks shawn]

Plant fasting: robotic gardening

This art display system was created by [Peter Sand]. It is called Plant Fasting and is comprised of a giant robot with interchangeable tools for various gardening tasks. Though the system is mostly automated, it can be controlled via a game pad. It has an Arduino as its brain and it looks like he’s done a completely custom setup for powering the interchangeable pieces.

Automatic grow light

gh1

We’ve covered automated plant growing before, but that project might be overkill for many situations. Many of us don’t need our plants to have facial expressions either. Sometimes, we just need a little bit of help. This automated grow light is a nice little project that supplies decent light when necessary. You can download the source files on the tutorial. It is currently set to supply an additional 4 hours of light, detecting the low light levels to turn it on.