aware of legal policies regarding the handling of edible fish and the use of food grade plastics and electronic devices.
• Sensor enclosure. During the travels the sensor are in contact with water, dust, and solid objects, Because of this, we protected them with waterproof IP66 enclosures. These enclosures can protect against fine dust and powerful water jets. We also protected the connections against dust and water with silicon.
• Isolation. The sensor probes work with millivolts (mV) and another sensor, or electromagnetic signal generates junk data. Because of this, we implemented a robust electrical isolation from other sensors and the outside electrical noise, especially from the pumps of aerators.
• Calibration. It is a restriction on the continuous use of the sensor probes because they are very sensible to human manipulation, dirty, temperature, salinity, and atmospheric pressure. For example, the dissolved oxygen sensor takes approximately 20 minutes to obtain a right measure, and it requires re-calibration whenever power is disconnected.
• Sensing frequency. It is important to define a sensing frequency that provide a good data granularity while minimizing the amount of data storage. We start using a one-second sensing frequency. However, this frequency generates many repeated data because water parameters do not change so fast. Finally, we use a one-minute sensing frequency.
• Management. The company staff needs to configure, monitor and control each sensor node independently because thresholds depend on the size of the fingerlings that it contains. They also could turn off the monitoring process in the containers if there are no fish. We implemented a remote controller from the web portal, and we do not provide this control to the truck crew to avoid that they accidentally turn off the sensor nodes.
• Energy supply. Special care is needed when connecting the energy and the ground to Arduino boards. We implemented a no-brake energy supply for the nodes and display devices. Extended energy cuts can generate the loss of data and consequently, an uncertainty of water quality conditions. Additionally, we installed energy conditioners since the quality of energy is a problem when mounting the sensing platform on the truck.
7.2. Sensor nodes interconnection Wireless sensors networks is a trendy technology, as we mentioned in the related work section. As a first prototype, we implemented a wired interconnection of the sensor nodes with the sink node. This solution has problems related to voltage drop and signal noise. To solve these issues, we are planning to implement a wireless intercommunication of sensor nodes and sink node. In this same sense, it is