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• Transistor Switch - For Vibrator Motor

  Jayahari J • 08/18/2014 at 18:32 • 0 comments

  Now addition of a vibration motor as a feedback for touch/kiss is considered. For this we will be using a BC547 transistor - The base is connected to a resistor and in turn to an arduino. The emitter is connected to ground where as the collector is connected to one end of the motor while the other end of the motor is connected to VCC. When the arduino pin goes high, The motor's flow gets complete and it just buzzzzzzes :)

• Capacitive Touch

  Jayahari J • 08/18/2014 at 17:35 • 0 comments

  Testing Capacitive touch library with Arduino - With a net 400 K Ohm resistance for sensing and a whole copper clad as input. The Cap Sense library worked like a charm !

  So a KISS activated toy is on the way !

• 7219's magic

  Jayahari J • 08/17/2014 at 18:43 • 0 comments

  I followed tronixstuff's Guide for 7219, Initially I had troubles - This was because I was using a 8x8 display which was lying around in my parts bin. 

  The pins were not mapped properly by me, and China LED's no datasheet - so went ahead and connected +5V to the first pin of the matrix - Then to the 12th pin connected Ground through a 10K resister - Voila - The last LED glowed !

  Now figured that the first four pins are Common Anode row pins - Followed by 8 pins pertaining to Common cathode for RED LED's (yes I was using a bicolor Matrix) and the last four (20 to 24) were the rest of the Common Anode row pins.

  At many online sites, There were specific products called "Common Anode" 8x8 Matrix - Don't believe - Its a matrix - 8 Pins are common anode and 8 Pins are common cathode !

  MAX7219 datasheet says its Common Anode ! Yes its common Anode but only for segment displays - For Matrix displays MAX7219 is always a friend!

  A picture to end the the log!

• Selecting Components

  Jayahari J • 08/17/2014 at 18:12 • 0 comments

  Selection of components is a major task in any project, with previous project exectuion using arduino and huge number of LED's, I used simple shift registers and ULN2003 - The software complexity increased many folds and I used to run into out-of-memory errors.

   With LED's the brightness when one LED is "ON" and when the whole row is "ON" should be the same.

  Hence time I chose MAX7219 as it takes care of the LED matrix, Brightness, refresh rate etc.

  Why RED LED Matrix ? RED is the color of love and Danger !

  Why DIP components ? Its easily available in India - in low quantities!

  Perfboard setup ? Yup !

  Which/what Switch is used to trigger ? Physical or Capacitive or Kiss .....  Still working this out !

  Message - How is the user's message get into the system? While Programming .. Bluetooth .. Sterio cable .. Still working this out

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