Project Requirements

1. The Remote node senses the humidity in air, moisture in soil, temperature and light during day as well as night and communicates it to control Node. Control Node takes decision based on the values and communicates to remote node the amount of water to be irrigated.
2. If any of the sensors fail, the system based on the value of other sensors approximates the results and works in degradable mode.
3. The system should perform a self in build test on startup and on failure of any sensor(s) the system retries for a timespan. If built in self-test still fails, based on the results, the system continues to work in degradable mode
4. The system displays temperature moisture or humidity on 7 segment display based on the user requirements.
5. The buzzer is activated if moisture in soil rises the threshold value indicating fault condition.

Application Tasks

Main Task The Main Task is the parent thread, implemented using asynchronous threading strategy to manage child threads. The Main Task performs following functions -

• Child Thread Management Function
• Controlling Actuators

The main task creates threads that perform the following functions –

• Temperature Sensor Task
• Light Sensor Task
• Moisture Sensor Task
• Synchronized Logger Task
• Communication Task

CHILD THREAD MANAGEMENT FUNCTION

The parent thread keeps the track of children tasks to check if they are alive and running on specified time intervals or dead and stuck for a specific timeout. This can be achieved by using Heartbeat notification from all child threads to the parent thread using request response mechanism. When requested to stop the task, the main task should clean up everything, issue exit commands to the child threads and terminate gracefully

CONTROLLING ACTUATORS

Based on the user requirements display values of temperature, humidity and moisture Based on the values of sensors turn on/off the motor Turn on buzzer on identification of fault conditions

TEMPERATURE TASK

This task is concerned with the Temperature Sensor TMP102 with I2C. It wakes up at a regular interval to collect data from the sensor. It consists of read and write functions for sensor registers and modify configuration registers. API calls getTemperature()

LIGHT SENSOR TASK

This task is concerned with the Light Sensor APDS-9301 Light Sensor. It wakes up at regular intervals to collect data from the sensor. Sample API List APDS9301_GetState(uint * LUX); //Get state light/dark APDS9301_OutputLuminence(int * temp);

MOISTURE TASK

This task is concerned with the moisture Sensor SEN133322 Sensor. It wakes up at regular intervals to collect data from the sensor.

Sample API list GetMoisture();

Sample API list Gethumidity();

SYNCHRONIZED LOGGER TASK

This task is concerned with logging data from various on-board sources. As this interface is going to be accessed by multiple sources, synchronization is needed to maintain data consistency. In this project, data protection is achieved using Message Queue. The log file path and file name are configurable. This is accomplished using command line options. Once the process is requested/forced to close, it should close all file handles and terminate gracefully. Each log entry contains the following information: timestamp, log level, logger source ID, Log Message

COMMUNICATION TASK

This task acts as an interface to Remote Task and Control Task The Remote Task and Control Task communicates using NRF module

Application Tasks

Main Task The Main Task is the parent thread, implemented using asynchronous threading strategy to manage child threads. The Main Task performs following functions -

• Child Thread Management Function The main task creates threads that perform the following functions –
• Logger Task
• Communication Task
• Control Task

LOGGER TASK

This task is concerned with logging data from various on-board sources. As this interface is going to be accessed by multiple sources, synchronization is needed to maintain data consistency. In this project, data protection is achieved using Message Queue. The log file path and file name are configurable. This is accomplished using command line options. Once the process is requested/forced to close, it should close all file handles and terminate gracefully. Each log entry contains the following information: timestamp, log level, logger source ID, Log Message

COMMUNICATION TASK

This task acts as an interface to Remote Task and Control Task The Remote Task and Control Task communicates using NRF

CONTROL TASK

The Control task has an algorithm based on the sensor values decides the outcome, that is, the amount of water to be irrigated.