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Product Design of a 4 wheel differential drive robot

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Batman Key chain with ESP8266

Have recently bought a small batman key chain from amazon. It  has a small button when pressed lights the batman eye with white light and sounds a pathetic sound (:(). So I thought of opening it.
It has enough space to put some custom electronics. So I thought of customising it a bit. This is what it looks before customising.


This is what it looks when adding a little bit of electronics into it. It has an esp8266 with 3 SMD LED (Red, Green, Blue) that can be independently controlled. It has a small speaker (from a headset) which plays a pac man tone. It is powered with a 3.7 V Lipo battery with an option to charge with an USB cable.

Batman keychain is playing pacman tone... :) I know it's a bit wierd, but couldnt find a good tone (which can be expressed as a piano tone like C4, B#2, ...) for batman. Will replace it once found a better one.

Things to add further
  • Pressing for a long time will enable a hotspot
  • Option to change the tone by writing it to EEPROM on the go (ESP8266 has 512 bytes of EEPROM).
  • Option to play PCM encoded 8 bit WAV file.



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