Design and implementation of an Arm Cortex M0+ based low power sensor node for an IoT based plant monitoring system

Plant monitoring system is used to monitor the environmental condition in around the plants to have proper growth and maintenance. In the proposed system, a sensor node is designed which runs with battery for longer duration and measuring parameters like temperature, sun light intensity, moisture level and carbon-dioxide. Especially capacitive type moisture level sensor is designed in order to measure the moisture level of the soil. A wireless Sensor network (WSN) is created to sense parameter related to individual plants. Here a MCU having inbuilt 16 bit ADC is used and programmed to transmit the data using XBee S2C as router. The XBee S2C is configured in low power mode using hardware control. The data transmitted by sensing node will be received by coordinator XBee S2C connected to Raspberry Pi using UART acting as Brain unit. This Raspberry Pi is also connected with CO2 sensor using UART as communication protocol through a 2:1 MUX as Raspberry Pi has only one UART. The data is processed and pushed to the server through Wi-Fi. Now a days Internet of Things (IoT) is playing a prominent role in order to have communication between things and people and between things and things. IoT technology enables to improve the access to care, most importantly it reduces the cost of care, it reduces human interruption and also increases the quality of care. Hence IoT is used in this work. So, the final processed information is stored in the cloud and at the recipient side a mobile application (app) is developed in order to intimate the information to the owner of the plant regarding the health of the individual plant.