Bluetooth controlled LED lamp

This project can be used to create a cool desk lamp which can be controlled remotely using an android app. It uses a microcontroller development board – Arduino UNO and an HC05 Bluetooth module to control a lamp containing 5 separate led modules containing 3 LEDs each, remotely using a simple Android app. It was created by the Innovation cell of my college.

Required components:

  • Arduino UNO board
  • 3mm LEDs – 15 pc.
  • HC05 Bluetooth module
  • Connecting wires
  • Android phone
HC05 bluetooth module
Arduino UNO

About the project:

The led modules are turned on and off upon receiving command from the android app via the Bluetooth module. The app, which was created using MIT app inventor, sends data in the form of numbers or characters which can be read by the microcontroller. The modules can be controlled based on the variables received using a simple if else ladder.

For eg: upon receiving the number “1”, turn the 1st led module on.

Thus the lamp can be controlled remotely without any direct interaction.

Circuit:

  • Each module contains a set of 3 LEDs connect in parallel connection. This current is divided among these 3 LEDs, hence, there is no need of a series resistance to limit the current.
  • The modules are connected to digital pins 2 to 6 of the Arduino UNO.
  • The Tx pin of the HC05 is connected to the Rx pin of the UNO and the Rx pin of the HC05 is connected to the Tx pin of the UNO. This is because the data transmitted by the HC05 is received by the UNO and vice versa. The HC05 communicates with the UNO using these pins.
  • While uploading the code to the UNO, make sure to disconnect the Tx and Rx pins from the HC05 as the UNO uses these pins to copy the code and the Bluetooth module may interfere.
  • The HC05 is powered by 3.3v from the UNO to its Vcc pin and the ground of the UNO to its ground pin.
Circuit on breadboard

Possible Modifications:

  1. The lamp can be made to be controlled by an IR remote using an IR receiver.
  2. Brighter LEDs can be used to make a brighter lamp but they would require an external power source.
  3. RGB LEDs can be used to get any color of light you want.
  4. The overall project can be made more compact using an Arduino nano.

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