Sat. March 14th 2020 Projects and Challenges

1) Hack Challenge, by George
Modify a window alarm to be a useful or entertaining device. Window alarms to be supplied free March 14th, one per attendee.

2) Hack Challenge, by Deid
New “Christmas Light” patterns

3) … bring projects that you want to share or need help with… If you like, email a description to be added to this page.

It is fun to repurpose battery powered consumer products.  For instance, here is a Leak Detector made from a window alarm.  The article includes the window alarm schematic.  

And George made a bike theft deterrent alarm with remote radio alerting from the same window alarm.

In normal operation, the window alarm senses separation from its external magnet via its internal reed switch and feeds its piezo disk with an oscillation.  The window alarm runs on 3 button cells and draws no current when the reed switch is open. There is also a slide switch to enable/disable the alarm.

Here is a photo of the circuit board:  The OUT signal from the 8 pin oscillator chip is a 10V DC wave, pumped up by the inductor from 5 volts. A voltage divider can be added to lower this chip output signal to less than 5v to feed another device.    

Or the piezo can be used as a microphone, providing about 100mv into a very high impedance input

In May we can show what we achieved.

New “Christmas Light” patterns

Deid successfully connected a 50 light string of addressable LEDs to an ESP8266 to cause the lights to light and change colour and move and …

Deid created the following patterns:

  • Primary
  • Random
  • Web Safe
  • Follow
  • Lead
  • Random On ***
  • All On
  • All Off
  • Rainbow
  • Moving
  • Colour
  • Christmas
  • Rainbow Group
  • Dual Colour ***
    *** Shown in the images

*** shown in the included images.

The ESP8266 C code to do this can be found here.  Deid makes no representation that the existing code is good.  In fact he knows some of it is not. Feel free to fix.

The challenge is to add more patterns and the code to implement the patterns.  If you send Deid the code he will load and try the code. Unless someone comes up with a better way for folks to test remotely.


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