2. Motivation
Of all the water used in the world, 70% is
used for irrigation and agriculture.
Water waste reduces the amount of safe
drinking water available for humans and
destroys aquatic environments.
This project aims to use “free”, sustainable
power to reduce water waste in the irrigation
process.
3. Battery Control Circuit –
Overcharge Protection
Protects the battery
from charging too high
Overcharged batteries
can leak sulfuric acid
Electrically disconnects
solar panel from
battery if battery is fully
charged
4. Battery Control Circuit –
Discharge Protection
Protects the battery from
discharging too much
Batteries that discharge
too low have excess
build-up of lead sulphate
and cannot charge.
Electrically disconnects
load from battery once
voltage reaches a
threshold voltage
5. Arduino Microcontroller
An Arduino is an open-source
microcontroller, which makes it easy
to use and easy to share with
others.
Arduinos use a programming
language similar to C, a language
that many people know.
It makes it possible to carry around
a computer without needing
something as big as a laptop.
It allows communication among the
different pieces of the system.
6. Moisture Sensor Unit
Houses moisture
sensor and
temperature/
humidity sensor
Reads moisture from
soil and sends
information back to
Arduino as a voltage
7. Hysteresis
If moisture is above
graph, flow valve turns
off
If moisture is below
graph, flow valve turns
on
If moisture is in the
middle, it keeps doing
what it’s doing
8. Flow Valve
Opens when 12V is
applied across it
Closed otherwise
Controlled by Arduino
with a transistor
5V from Arduino is not
enough to open valve,
but is enough to signal
a transistor
9. Flow Meter
Measures amount of
water passing based
on rotation of internal
wheel
Returns pulse when
the wheel has
rotated through a
certain angle
10. Touchscreen
Allows user to set
desired upper and
lower moisture levels
Allows user to view
moisture,
temperature, and
water usage data
11. Tying It All Together
Solar
Panel
(And
Circuit)
Battery
(And
Circuit)
Arduino
Moisture
sensor
Flow
valve/Flow
Meter
12. Results
Irrigation system
keeps moisture of
soil between higher
and lower
thresholds.
Solar panel charges
battery, and battery
circuits control
charging of the
battery.
