Micro timer for garden irrigation control

Lately we have seen the advancement of technology and the possibilities that this offers us. With this, we see services that were previously done exclusively by people now being performed by equipment and machines. This occurs with the aim of making people's lives easier and offering better working conditions, more efficiency and agility, reducing the amount of human errors in the process.

Field work often becomes exhausting and often repetitive work, with routines without much change in general. For farmers, one of the functions most present in their daily lives is watering the gardens and plantations, often being carried out at specific times of the day, when the farmer considers the most favorable time.

The project in question has the proposal to be an ultra-compact timer capable of activating inductive loads (water pump) in a satisfactory way, occupying as little space as possible and, mainly, at a low cost.

Wiring diagram:

The image shows how simple it is to connect the timer to the water pump, avoiding complications and reducing the possibility of errors during the assembly of the irrigation system, allowing the user to acquire several units to use in different sectors of the field.

For example:

A producer who grows plants with different water demands: the producer can set up individual sprinkler systems for each plant, with different irrigation times depending on the needs of each crop.

The timer circuit

MCU:

The timer uses a STM8S003F3U6 microcontroller, one of the smallest and cheapest on the market. It is well known for its wide range of products available today.

Source code:

The STM8 development tool is available free of charge. ST Visual Develop or even the Arduino IDE platform can be used. For more accessibility, the code provided for the timer was created in the Arduino IDE.

Operation mode:

Ideally, the operating mode chosen as a reference was to turn on the irrigation pump twice a day, that is, every 12 hours, in the morning and in the afternoon. The irrigation time chosen was 2 minutes.

Operating times can be freely modified by changing the code.

load driver:

The load drive driver used was a triac driver due to its low price and little space used, allowing the manufacture of the board with reduced dimensions.

noise reduction:

A snubber circuit was used to reduce the EMI interference generated by the switching of the inductive load (motor) by the triac. The R and C values of the snubber may need to be modified depending on the water pump used.

Benefits:

It facilitates carrying out routine activities in the cultivation of plants and is also useful for those who have their own small garden at home and want to travel for a few days, but do not want to harm their plants, this being a viable and economical alternative.

Schematic:

Components list:

Other applications:

The timer in question is not restricted to the proposed objective, and can be used in various applications such as, for example, vacuum sealers, timer for activating night lights, etc.

Attention: the current capacity of the triac used in the project is 4 amps, but the dissipation capacity offered by the PCB layout has not yet been tested.