Bluetooth for light

Discussion in 'Embedded Systems and Microcontrollers' started by Motanache, Jul 25, 2015.

  1. Motanache

    Thread Starter Member

    Mar 2, 2015
    I want to design a bluetooth remote. I want to turn on the light (leds and battery). The first thing I wanted to use was a HC-05 and RN4020. In the place where I live I could not find any of these components.
    In one shop they were selling minimum 5 or 10 pieces.

    I do not know what to do.
    I am looking for a cheap way to do this.

    There is amother way using PIC24F with USB host and USB bluetooth dongle, but it is too difficult.
    New ideas are welcome so as to use mobile phone as remote.
  2. John P

    AAC Fanatic!

    Oct 14, 2008
    Just a couple of weeks ago I bought some HC-05 Bluetooth modules to play with, and I've got them working successfully. I have no experience with that RN4020 component, but I'd be cautious about the HC-05 and low energy Bluetooth--are they compatible?

    What I've been able to achieve with the HC-05 is getting two of them to communicate with each other, with one being master and the other slave, and one of them communicating with my computer as a slave, where the computer hasn't got Bluetooth built in, but I used a Bluetooth dongle plugged into a USB port. Note that the HC-05 is intended to function with a serial port on whatever it connects to. That suggests at minimum a microcontroller with a UART to operate the light, but I suppose you could set up some sort of pulse-width comparator and send it a single character 0x00 or 0xFF, and turn the light on or off based on how long the line went low for.

    If obtaining parts is a problem for you, you could do what I did--buy several HC-05 units from a Chinese vendor via eBay. It was cheap and easy, but I know mail to some countries is slow and uncertain, and may involve you having to pay an outrageous customs bill. It depends where you are.