# An Autonomous Wireless Device for Real-Time Monitoring of Water Needs
## 5 Discussion  
Estimating the energy efficiency for an IoT device is very difficult when there are several communication technologies, electronic components, and measuring devices, as well as a multitude of environmental conditions and particular situations for each crop and its needs. These limitations are commented upon in some works [40]. It was not the objective of this work to modify hardware and software parameters to reduce consumption, but to decide on the most appropriate technology and components that would allow us to develop an end-device with low consumption. We also decided on the best intervals for data collection and sending, and the microcontroller was programmed to achieve minimal consumption. Finally, we compared the results with other similar works in the field of smart irrigation. The results achieved in this study improve upon the recently published ones. For instance, [13] present a node formed by the Msp430F1611 Texas Instruments processor and wireless communication at 2.4 Ghz with a gateway. To measure the different terrain parameters, they used two Hydra Probe II sensors. The measurements were taken every 30 min, obtaining an average consumption of 0.5035 mA. The calculated autonomy was 223 days, achieved by installing a 2700 mAh battery. In [1], a device using LoRa communication was developed to measure temperature and humidity parameters and soil data. With a time between measures of 60 min, the average consumption of the device was 0.4026 mA, achieving a range of 73 days for a 2400 mAh battery. Unlike the previous case, the author corrected the duration of the battery by the factor 0.75, thus achieving a result closer to reality. The GAIA2 system [5] communicates via radio at 2.4 GHz with a gateway. In laboratory tests, with a node and a humidity and temperature sensor SHT71, an average consumption of 0.089 mA was obtained. On the other hand, a real field experiment was carried out in which two MPS-2 sensors were used, capable of measuring the water potential and soil temperature, obtaining a total battery life of 56 days. Finally, the LoRa irrigation system proposed by [19], which uses a lithium battery with 4800 mAh, consumes, in their different operative modes, 2.0987 mA on average, equating to a battery life of 57 days under the same conditions as our experiment. We presented a system capable of an average consumption of 0.069 mA, thus providing a battery life of up to 724 days. If we compare these results with those obtained in previous articles, we can see that consumption has been reduced significantly, along with a significant increase in battery life. The following Table 4 shows a comparison of the results obtained in other studies. Figure 8: User interface of the application web. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Method** & **Technology Tested in Smart** & **Average Consumption** & **Time between Measures** & **Sensors** & **Battery Life Spotified in Each Paper** \\ \hline Our BoXmote & LoRa/2200 mAh battery & 0.0690 mAh & 30 min & 1 \(\times\) EC/2016 JS, 1\(\times\) KCH20 STE, 1\(\times\) DHT11, 1\(\times\) light-dependent resistance & 724 days \\ \hline  & & & & 1 \(\times\) TCN/5A digital temperature sensor, 1\(\times\) & \\  
If we compare the results obtained in our study with those obtained by [13], we can see that both devices take measurements every 30 min and have two sensors that measure various parameters of the soil. However, the average consumption obtained by our device is a reduction of 86% compared to the consumption of the other device. Regarding the life of the battery, our device is capable of increasing the life of the battery by more than 300% compared to the work in [13]. Comparing the results of our BoXmote with those obtained by [1], we can see that our average consumption is 82% less than that of their device. Bearing in mind that in this case the time between measurements is 60 min, this would mean that average consumption would be even higher if the time were reduced to 30 min.