GSM based Smart Home Automation is a very effective project for load monitoring & controlling. It has a smart intelligence system to monitor load status & temperature status. Based on the environment it can take various logical decisions. For example, if the temperature of a room get exceeds the pre-defined level, it turns on the fan. Turning the room lights with the presence of humans and so on. It also has a GSM module to control the loads using SMS.
- Arduino (as the Controller)
- GSM module (SIM800L)
- IR reflective sensor pair
- Temperature sensor (LM35)
- Relays (5V DC)
- Transistor (2N2222)
- Diode (1N4007)
- Regulated power supply (LM317)
In this block diagram, we’ve used an Arduino as the microcontroller, 2 IR reflective sensors to count humans, a temperature sensor to measure temperature, a GSM module to send SMS command to the controller, 3 relays to control the loads and a power supply unit to bias the whole circuit.
There are two modes in this circuit. One, the loads are being controlled depending on the sensor status. And other is SMS mode, in this mode loads can be turned on or off by SMS command.
In Sensor mode, the lights of the room controlled by counting humans with the help of the reflective IR sensor pairs. It counts up every time anyone enters the room and counts down every time anyone leaves the room. The fan and the AC of the room are controlled by the temperature controller. These turn on or off depending on the temperature of the room measured by the temperature sensor (LM35). If the temperature goes up to 30°C it turns on the fan and at 40°C, it turns on the AC.
If we want to run the device in SMS command mode, we have to enable the SMS mode by sending an SMS code.