Started off to work on a room automation system at my home.

1. Building LED modules for Room lighting

2. Replaced old SPDT switched on the switchboard with SPDT switches control appliances using relays with a 2-way configuration.

3.Setting up motors for remote controlled window curtains.

Recently got some cheap RGB LED strip from china. They did come with a small controller but the fact of being able to control it with a microcontroller to any colour required is quite exciting. That's why I built this simple (irf540) mosfet based driver to control it using arduino or other microcontrollers. I also wrote some basic arduino code to make it easier to interface my future projects with the LED strip . The code is available at my Arduino-LED-Lighting-Projects git repository here https://github.com/shreyaskulur/Arduino-LED-Lighting-Projects

This is a simple digital clock prototype I built to use a MAX7219 display driver IC. The device can show date and time obtained from a DS1337 based RTC Module. Both the maxim ICs used in this project MAX7219 and DS1337 were obtained as samples from the company. An arduino uno gets the current date and time from the RTC using I2C and sends the numbers to be displayed to the MAX7219 via SPI. The arduino code for this project is available at my github page linked below.

https://github.com/shreyaskulur/MAX7219_8x7segment_display

This is a Bluetooth controlled bot with four wheel drive. Its based on the Arduino Uno. A HC-05 is used for Bluetooth connectivity. Two separate L293D based motor drivers drive two motors each. (external power supply).

This project makes use of an arduino uno to decode messages from a RC-5 encoded IR remote and send serial data to the computer. The computer runs a simple python script I wrote to emulate keyboard based on serial input. I used to use this setup for quite some time while watching movies on my PC, only until I setup a media center on my raspberry pi.
The arduino and python codes are on my git hub page linked below
https://github.com/shreyaskulur/arduino-windows-interface

I made this circuit around 7 months back and have been using it regularly since then. It is basically two relays that can be controlled by an IR remote. The relays in turn switch a fan and a light source. What I like most about this project is that I can program it to use any IR remote. Since I have installed this in my living room,  I now use previously unused keys on my TV remote and set top box remote to control the relays.

Planning to soon make a circuit to replace an entire typical switchboard with relay or triac based switching and wall panel with capacitive sensors. 

I use a desktop at home and it's sometimes difficult to debug projects, since I have to get it to my desktop. Also, projects based on capacitive sensing gives different readings when connected to a PC and while running on a battery.

I had this 16 x 2 LCD display lying around for a while. I was not using it regularly due to its parallel interface consuming a lot of i/o pins from the microcontroller. So recently I decided to  build an atmega8 based board to which I can send data via the UART, I2C or SPI. The LCD just snap on to header on the board and the atmega8 manages the serial to parallel conversion and text formatting.

The conversion module consists of

• Atmega8 microcontroller running arduino based code.
• Reset button for the microcontroller.
• 5V regulator and a 5mm DC jack (I added it after taking these pictures).
• Preset (potentiometer) to set the LCD contrast.
• 6 pin programming headers to plug in my USBASP programmer.
• Male headers to plug in the LCD and for serial communication.

The microcontroller was programmed using an USBASP programmer and the code is written using the Arduino IDE. Basic code available on my github page here.

The program presently running on the device displays any incoming data via the RX pin. If no data is received for a predefined time, the device checks if it an RTC is connected to it. If found, the present date and time are displayed as a screen saver until any data arrives through the serial port.

DS1337C is a real time clock (RTC) from Maxim. Unlike the commonly used RTC DS1307, the DS1337 has an internal crystal and hence does not requires only a few pullup resistors to get it running. Also, this was the first time I tried PCB etching. The first try (picture on the left) did not yield a good result and got over etched. The second trial (picture on the right) was successful.

The RTC module after populating,soldering and labelling is finally ready for some configuration and testing.

This one is a small dev board I made with the attiny85. It has a reset button, 6pin isp programming header and of course breakout for the attiny i/o, power and ground headers.The board is designed to use the internal clock sources of the attiny and does not contain an external crystal.

Inserted a LED into a hot glue stick and connected it to a 3v cell to get this nice Glow Stick !!!!

Closeup Of a Dried Leaf On An Illuminated Surface

A Really Small Spider

Insects

Fabric

Fingerprint

The above photos were taken on a 5 MP smartphone camera. 

I made the adapter using parts I had lying around in my house.
The lens was scavenged out of a cheap laser pointer. The frame holding the lens is a piece of a junk circuit board. I then mounted it on old mobile cover so that I can use it easily anytime I want to.

To focus a subject, the camera has to be around 1 - 2 cm from the subject. Moving it in the vertical direction helps focus the subject.

 More photos and videos will be added soon!!

All of us generally have TV remotes lying around us with a lot of unused and unprogrammed keys on them. This project explores using these IR remote and a receiver for wireless communication. IR remotes are economic over modern modes of wireless communication such as bluetooth and wifi.

Here I am using a Dish tv set top box remote to control and customise the colour of a LED wirelessly. The colour (red, green or blue) is chosen using the coloured buttons on the remote and the intensity of the selected colour is varied using the volume and channel keys on the remote. The data of intensities of the three colours and the key pressed can also be sent to a computer over USB.



The LED could be replaced with a relay to control the lights and fans in the room. Doing the same using bluetooth will need you to launch an app, connect to the system and then control the switches. But with a TV remote, sending a signal to the arduino should not be a problem at all (specially if you are a television addict). So, we could have the useless "Theater mode" key on the  remote to actually switch off the lights and turn on your 5.1 audio system.

I breadboarded this simple circuit to introduce and demonstrate the basic logic gates to my friends as a part of physics presentation at school.

The circuit is based on IC 7400 (Nand-gate) and 7402 (NOR-gate). AND, OR and NOT gates are created using the NAND and NOR gates.

Two switches are used as logic inputs and two accompanying LEDs indicate the status of the switch. The third LED indicates the output. 

This project is a combination of capacitive sensing with paper-art.

It all started out as a popup card resembling a one octave Piano.

Later I added eight capacitive sensors, one for each key.

Some programming using processing and arduino and its WORKING!

I recently made this digital die using the Arduino micro controller and a few commonly available components. I also built a processing application for displaying the numbers on the computer screen.

When the device is switched ON or reset, it takes about 3 secs to config. itself to the surrounding lighting conditions. During this auto configuration the device registers two values ( highest and lowest ) and the midpoint of these values is used as the critical value (lighting condition below the critical value triggers the device). Once configured , the die can be used (to display random numbers between 1 and 6) by either pressing the switch or hovering your hand above the device. Moving your hand above the device changes the lighting conditions hence triggering the device. This auto config can also be used to change the sensitivity level of the device by controlling the lighting conditions during the configuration.