AVT 3135 Quick Start Manual

Electronic Bird Scare
kits
The presented scare is a very effective and
environmentally friendly method of bird deterrence. It
is a microprocessor-based version of the scare for
starlings. The sound emitted, with a volume of more
than 100 dB, will successfully flush out not only birds
but also small rodents from the garden or warehouse.
Circuit description
Flushing out birds from certain locations sometimes
becomes a necessity. Above all, the mass occurrence
of starlings can destroy the many-month work by fruit
growers. The presented microprocessor-based bird
scare was designed to effectively control bird pests. It
is sufficient as basic protection against birds
consuming the fruit from the plantation. The repellent
is a device that randomly emits a one-tone sound at a
very high volume. Thanks to the twilight switch, the
sound signal will only be activated during the day
and, regardless of the settings selected, the user can
be sure that the scare will not switch on at night.
The schematic diagram of the scare is shown in Figure
1. The circuit must be powered from a 12 V battery,
e.g. gel battery or stabilised power supply also with
12 VDC and an output current of approximately 1 A.
Characteristics
• randomly activated beep
• smooth adjustment of siren on frequency
• integrated twilight switch
• supply voltage level check - LED
• light sensor function check - LED
• power supply 12 V / 1 A (battery)
• board sizes: 40×62 mm
D1 diode in series with the power supply protects the
circuit against incorrect input voltage polarity.
Capacitors C1...C4 act as a supply filter. Input voltage
from the screw connector X1 goes to the US2
stabiliser. The LDO stabiliser was used to reduce
current consumption. The scare operation is
controlled by a US1 ATtiny25 microcontroller clocked
by an internal clock signal. Resistive divider made up
of resistors R3 and R4 connected to port PB3 allows
the programme in the microcontroller to measure the
battery voltage without the risk of damaging it with
too high a voltage. To make the circuit work sparingly
and only during the day, a photoresistor PH1 was
used, which, together with resistor R5, forms another
resistance divider. Voltage signal, dependent on
lighting, goes to the PB4 port of the microcontroller.
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ASSEMBLY DIFFICULTY
1