Nowadays, we have remote controls for our television sets and other electronic systems, which have made our lives really easy. Have you ever wondered about home automation which would give the facility of controlling tube lights, fans and other electrical appliances at home using a remote control? Off-course, Yes! But, are the available options cost-effective? If the answer is No, we have found a solution to it. We have come up with a new system called micro-controller based home automation using Bluetooth. This system is super-cost effective and can give user, the ability to control any electronic device without even spending for a remote control. This project helps the user to control all the electronic devices using his/her smartphone. We also added the functionality of dimming to one port from where you can remotely control either the brightness of the light or the speed of a fan.
Step 1: Hardware and Components
1. Microcontroller TM4C123GH6PM
The Cortex-M microcontroller selected for hardware-based programming and interfacing illustrations is TM4C123 from Texas Instruments. This microcontroller belongs to the high-performance ARM Cortex-M4F based architecture and has a broad set of peripherals integrated.
2. 5V relay module
3. LCD The liquid crystal display (LCD)
We are gonna use 16x2 LCD to show the statuses of our switch board.
4. Bluetooth Module HC-05
Bluetooth module to control the relays and dimmer circuit.
5. Mobile charger
Mobile charger to power the micro-controller as well as relays.
6. Plastic Switch Board Casing
7. 7 plug sockets
Step 2: Relay Control Circuit
This designing is easy to understand and implement. The received output from the Bluetooth is capable to alter the states of each and every plug we have in the board.
Step 3: Designing the Dimmer Circuit
First operation is Zero Crossing Detection. Zero Crossing is the point where input sine wave becomes zero instantaneously during its swing.
Second operation is triggering the Triac using the opto-isolator i.e MOC3021. Triggering should be done using the micro-controller and the dimming of the voltage is directly proportional to the delay in triggering.
Step 4: Making PCB
Proteus design, PCB layout is given in the diagram
Step 5: Coding
Code for this microcontroller is written in the Keil uVision Environment and is given below.
Step 6: Designing Android Applicaiton
We will be using the MIT App Inventor to make our android application for bluetooth controlled relays and dimmer.