Hello friends,I'm Ostin. I'll explain,how to control a fan and light using arduino through sms.
Let us switch on/off a fan and light through sms commands,actually i have designed the project for controlling a irrigation motor in the farm land,just for making tutorial i have applied it on a fan and light in my room
you must learn AT commands from the data sheet of your gsm module.AT Command usually varies on different gsm modules but not necessary in all cases.
it is a highly dangerous project for amateur, since we are dealing with 220 V - which can kill you. DO NOT try if you are rookie in electrical.
Step 1: What will you need to start the project!
1) Arduino UNO
2) GSM module sim900A
3) Relay module
4) Bread board
5) 2 Led's and wires.
6) Working SIM for GSM module
7) Mobile for sending sms
8) Fan and Light
Step 2: Connections
Always power up the gsm module with separate power supply 12v 1 A .And insert the SIM.
RX and TX of gsm module to TX pin0 and RX pin1 of Arduino respectively. Cross connection. rx to tx and tx to rx.Gnd of gsm module to arduino gnd.
relay1 to pin 7 and relay 2 to pin 6.
vcc of relay to 5v arduino.
gnd to gnd arduino
We are using Normally open connection in relay. so that we can trigger on and off the light . Hot line from supply is connected to COM
Supply line to the Ac light/fan is connected to NO. Gnd or - or other terminal in light/fan is connected directly.
Led 1 to pin 8 (fan status indicator)
Led 2 to pin 9 (light status indicator)
Step 3: Wiring
Unscrew the switch board and find the supply line for fan/light. Be careful while doing this step,always wear a slipper to avoid grounding yourself.
Connect those supply line to relay NO connection and hot line to COM of relay 1 and relay 2 . Fan to relay 1 and Light to relay 2.
Step 4: Sending sms
a1 turns on the fan.(relay 1)
b1 turns on the light.(relay 2)
a0 turns off the fan.
b0 turns off the light.
Step 5: Status
Green led indicates fan is ON
Orange led indicates light is ON
Both leds goes low when #a0b0 is sent.
Step 6: Code
Library is not needed, if you are using sim900 module with AT commands.