The monitoring of granaries were earlier implemented with wired networks in most Asia countries with obvious challenges that include high installation and maintenance costs, data acquisition delay, and high energy consumption. Most other works being implemented with wireless approaches presented inherent drawbacks that include inefficient coverage of the grain storage bins and high rate of node failure. This paper presents the design and tremendous advantages of deploying distributed wireless sensor network based on Digimesh network protocol, to monitor the environmental temperature, humidity and illumination of a granary system. The monitoring system has only one node type, and consists of a homogenous network in which all nodes route data and they are interchangeable. A node consists of Xbee transceiver modules, Arduino microcontroller and DHT22 Temperature/Humidity sensor, and it is being configured as low battery powered devices. The results were logged real-time on a personal computer for analysis, display and record. The results indicate a system which provides a better sleeping scheme and eliminate the single point of failure associated with Zigbee and some other network protocols.

One major feature of a granary is the uneven distribution of temperature and airflow. Due to the large variability in the parameters to be considered in characterizing the feature, a pilot test serves as the better way to performing the experiment, which subsequently affects the airflow velocity distribution, and is very difficult to determine by natural experiment. This paper develops a model for uneven airflow and temperature distribution through the layers of stored grains, relative to the indicated parameters. The study aims at predicting the various thermo-physical properties of maize grains using the developed model with the incorporated several expressions obtained, and compare with the measured values through the deployed pilot mini silo. To validate the model, the bin was aerated with forced air at constant humidity and temperature. A mini cylindrical silo was also developed and deployed with bulk grains for a pilot test. The predicted results were compared with the measured values of the temperatures obtained in the various locations of the pilot silo. The two results were closely related, thereby establishing the validity of our model. The model provides information on the direction of flow and velocity in each location within the stored volume of grains, and data for grain cooling, airing and drying in the bin. The developed model is useful for predicting the temperature distribution, airflow and the cooling time for bulk grains under varying aeration conditions, and suitable for optimizing the design and operation of granary systems.