Skip to main content

Featured Post

Product Design of a 4 wheel differential drive robot

Post a Comment

Clap Switch

For some time I was thinking of making a simple clap switch for my room. ( Kind of lazy to go and switch off the light and fan every time... :-) ) First get it work on a breadboard.

"Circuit is simple and straight way. Feed the output from the mic to a comparator. The output of comparator will act as the trigger for micro-controller. Micro-controller detects the pattern and enable the corresponding relay switch. Micro-controller always waits for an interrupt (a clap). If a clap is detected it will wait and counts the following claps within a period of 1s. It will discard miss claps and only takes into account the pattern that is programmed. 2 claps means light on/off & 3 claps means fan on/off. There will be separate switch to enable/disable the clap circuit and precedence will be given for the physical switch. That means if the physical switch is on regardless of the relay state light/fan will be ON. If it's not then it will depend on the clap circuit."

Code here.

This is a video of detecting sound above a threshold value that can be set by a potentiometer. 
Next is to get it working on a general purpose board. ( Also need an AC to DC converter. I used an old phone adaptor for that purpose)
Here is final thing. (With switchboard open to show relay switching)
It will detect claps even when sound is playing in the background.

But things won't work if the volume is too high. Also it considers loud voices as claps. (Kind of obvious anyway) But it is smart enough to discard continuous loud noises. But if the loud noise matches the pattern then relay will be misfired. Both light and fan can be switched on and off separately. And there is a separate switch to disable the clap switch (When I need to hear music as loud as possible :-)).

Labels:

Comments

Post a Comment

Popular posts from this blog

Plymouth theme for Ubuntu

Bored of having the same boot animation screen again and again? There are plenty of Plymouth themes available out there. This is a theme I created by slicing some cool gif files I found online. You can download the theme and find the installation steps on my github account. ( https://github.com/krishnan793/PlymouthTheme-Cat )  The theme is created for Ubuntu 16.04. But this can be installed on previous versions with slight modification. If you have a slow computer then you can watch the whole animation loops. (The VM I used to record the screen was fast though. :))
Post a Comment
Read more

Getting started with GPIO (Testing GPIO with a multimeter)

There are 65 possible GPIO pins that you can control. Some of the GPIO pins are normally configured to different functions. Let's play with one of them. Go to the beaglebone website and figure out the header pin corresponding to gpio23. The gpio23 is mapped to the 13th header pin. In this tutorial we are testing the gpio23 output using a multimeter (Do not connect an LED directly to BBB IO pin). First go to following directory cd /sys/class/gpio / Then make gpio23 available echo 23 > export A new directory will be created. Open gpio directory. cd gpio23 The direction of IO will be normally set as in (input).  To make it as output, echo out > direction Then set the pin to high using echo 1 > value Measure the voltage at pin 13 of P8 header. If its 3.3 V then you are on the right track. Pin 1 and 2 will be ground. You can connect the negative terminal of multimeter to pin 1 or 2. To set output as zero, echo 0 > value After finished wit...
Post a Comment
Read more

Serial Port Communication in Linux using Minicom

First of all install minicom using apt-get install minicom or directly download the .deb package from  https://packages.debian.org/sid/minicom  and install it using dpkg -i <package name> After install type minicom -s to setup the minicom for using your serial port. Select Serial Port Setup and type A to select serial device. It will be shown as /dev/modem replace modem with  your serial device. Press Enter twice to save. You can also setup boadrate and all those stuff in the Serial Port Setup. After that you can save your configurations. Select Save Setup as. Then type a name and press enter to save it. If you wan't to open your configuration later, type minicom <configuration name>
Post a Comment
Read more