Assessing the Reliable Data for Wireless Sensor Network Based Capacitive Soil Moisture Sensor Monitoring System
Salmuna Sajjad Mishi, Ir. Eka Firmansyah, S.T., M.Eng., Ph.D., IPM; Ir. Agus Bejo, S.T., M.Eng., D.Eng., IPM.
2023 | Tesis | S2 Teknik Elektro
Providing accurate soil humidity with a capacitive soil
moisture sensor is challenging. The humidity of the soil is known to change
slowly. However, due to the nature of the capacitive sensor, which is sensitive
to environmental disturbance, the received humidity reading taken by the sensor
could change drastically which is not reflecting the actual soil humidity
condition.
In reducing the variation, data averaging could be incorporated.
It is known that the longer the averaging points the lesser data fluctuation
will be. However, in wireless sensor applications where energy usage should be
as minimum as possible, the faster the sampling period gives more energy
penalty.
In this research, an empirical experiment determined how fast
the data sampling and the number of averaging points result in the best soil
humidity data taken by a capacitive sensor. With the criteria of least data
variance and Mean Squared Error (MSE) with the sampling period result in 200 ms
data sampling with a 1000-point average gives the best data quality.
Providing accurate soil humidity with a capacitive soil
moisture sensor is challenging. The humidity of the soil is known to change
slowly. However, due to the nature of the capacitive sensor, which is sensitive
to environmental disturbance, the received humidity reading taken by the sensor
could change drastically which is not reflecting the actual soil humidity
condition.
In reducing the variation, data averaging could be incorporated.
It is known that the longer the averaging points the lesser data fluctuation
will be. However, in wireless sensor applications where energy usage should be
as minimum as possible, the faster the sampling period gives more energy
penalty.
In this research, an empirical experiment determined how fast
the data sampling and the number of averaging points result in the best soil
humidity data taken by a capacitive sensor. With the criteria of least data
variance and Mean Squared Error (MSE) with the sampling period result in 200 ms
data sampling with a 1000-point average gives the best data quality.
Kata Kunci : soil humidity, capacitive sensor, wireless sensor, energy, sampling period, variance, MSE