The presented project is simple, but efficient in medium distance irrigation. In this circuit, the time base is a 555 that generates a clock signal that is applied to a 4017 counter. The pulse frequency can be adjusted using a 1 M ohm trimpot. The valves used are of the hydraulic solenoid type found in a Brastemp washing machines, but other equivalent and larger ones, including the three-phase ones can be used. The robot can also be programmed to be used only at night or only during the day. The program is made through jumpers in RL-9, as it is in the circuit that identifies whether there is sunlight.
