AMMS Smart Irrigator, technology at the service of plants

Welcome back to our workshop, today we are going to talk about a project that we have been working on for months together with Paolo and Idris, two of our collaborators, namely a 'multi-channel smart sprinkler' interconnected to the AMMS network.

What is a sprinkler?

A sprinkler is an electronic device that allows you to manage and automate the watering of your garden or lawn, using sensors and intelligent algorithms to adjust irrigation according to various environmental factors and the specific needs of plants, as well as optimising consumption by cutting down on water waste. Some models are also able to monitor how much rainwater has been used compared to that taken from the aqueduct, manage the reservoir independently and dedicate a customised amount of water to each plant.
The sprinkler can be used in a variety of contexts, both domestic and agricultural, and are highly utilised especially during periods of drought or in areas without adequate natural rainfall.

There are many types of sprinklers, of which we leave you the best known in the following list:

Drip (or micro-irrigation) sprinklersThese sprinklers release water slowly and directly at the base of the plants via pipes and drippers. They are ideal for precision irrigation and are very efficient in terms of water use.

Static sprinklersThese sprinklers have a fixed head that sprays water in a specific direction. They are ideal for smaller areas and flower beds. Common examples include fixed spray sprinklers.

Oscillating sprinklersThese sprinklers have a bar that moves back and forth, spraying water in a rectangular arc. They are useful for irrigating rectangular areas such as lawns and gardens.

Rotating sprinklersThese sprinklers have rotating arms that turn 360 degrees, spraying water in a complete or partial circle. They are effective for covering large areas evenly.

Pulse sprinklers: These sprinklers use a pulse mechanism to spray water in intermittent jets, covering large distances and wide areas. They are often used in agricultural applications and large lawns.

Why make a smart sprinkler?

The above-mentioned sprinklers often work through mechanical mechanisms, or through an on-off circuit, thus without monitoring how much water the plant actually receives and its real irrigation needs, also leading to situations of high water waste and crop damage.

To remedy this over time, a series of increasingly technological sprinklers have come out, starting with timers, which make the mechanism run only under certain time conditions, rather than a single relay, i.e. using a sensor placed in the ground to start the entire sprinkler. These solutions, mostly commercial, only partially mitigate the procedural problems, as they are in any case insufficient to monitor the entire sprinkler line in real time. The most common of these can be found in plants far from the sensor, the dripper too close to the sensor (thus a too early disconnection of the water supply routine), pressure residues that still allow water to escape from the dripper and pipes that are too long to guarantee constant irrigation.

Our solution - the 'Springarol' prototype

Springarol, this is the name of the first prototype realised by the duo, is mainly designed to be applied in the open field, without connection to the aqueduct or to the mains combined with drip irrigation; it is applied to 1000-litre IBC tanks or other reservoirs and is powered by a solar panel that charges a 12-volt battery via a voltage regulator. The system uses a moisture sensor inserted in the soil and activates the solenoid valve and the immersion pump when the humidity drops below the set threshold. To favour the diffusion of water in the soil and to avoid overheating of the pump during prolonged use, the irrigation phase alternates between a period when the pump is activated and one when it is paused, all managed by a simple local interface. There is also a reservoir level control to avoid burning out the pump in the event of a water shortage.

Our solution - A 7-channel smart box

Springarol's main limitation comes from being single channel, i.e. a single moisture sensor and a single irrigation channel. In addition, weather analysis is not contemplated, so there is a risk of irrigating plants just before rainy phenomena, wasting water from the tank and risking over-watering the plant.

To remedy this, we did a total revamp of Springarol's electronics, firstly moving from an ESP8266 to a much more powerful ESP32, which allows us to extract much more potential from the design, thanks to the microprocessor's greater memory and operating frequency, while still guaranteeing WiFi and Bluetooth connectivity.

To increase the irrigation channels instead, we relied on a ULN2003A driver, which allows us to drive the 7 relays without the need for other components. In case the relays are not used, it is possible by means of jumpers to disable the line in question and to extract additional GPIOs to those arranged on the board

There are also status LEDs to indicate which relay is active at that instant, useful for system debugging operations.

The forecasting aspect of the system, on the other hand, is provided by a rocker-type rain gauge, the connection circuit of which is copied from that of WeatherIOT

The board's pinout guarantees a high degree of customisation of the installable sensors, allowing the board to be used as the basis even for IoT applications other than the sprinkler, such as the hydroponics project in collaboration with Phil3D, which we will discuss later.

Integration with AMMS

The main aim of the project is to integrate smart applications to AMMS, allowing the environment to be monitored and the data to be used to improve and streamline irrigation activities

For example, it is possible to predict a sudden thunderstorm and wait until the event is over to see if it is still necessary to irrigate the plants, as well as to monitor how much rainwater has been retrieved perhaps from a gutter and how much is used in the next irrigation, thus measuring the 'withdrawal-application' ratio and reducing water wastage. It is also possible to call on the AMMS system to measure other parameters such as environmental temperatures to avoid irrigation at times unfavourable for the plant, saving the configuration parameters as well as the measured values in a microSD or in the sprinkler database, providing a fundamental service for the farmer.

In the future, it will be possible to interface additional plant sensors, thus making the AMMS Smart Irrigator the perfect solution for environmentally friendly and efficient gardens and crops in every respect, reducing the environmental impact and limiting the damage that climate change is doing to mountain farming.

Current state of work

At present, the system runs via a 'porting' of Springarol's programme, adapted to the ESP32's new GPIO from the 8266, with only one soil moisture sensor, although tests are already underway to implement additional sensors and irrigation channels. The system holds up even under high load conditions, testing it to irrigate a line of balcony flowers at one of our customers.

The system is currently powered by a photovoltaic panel with a battery, with a view to conducting tests to optimise consumption, with initial results that are giving us hope for future improvements, as they give us an excellent basis on which to work to expand the project.