Matt Resolved to End the Morning Madness

February 03, 2004

Tired of a wakeup call at the crack of dawn, Matt decided to train his roosters to be less vocal. So he built a kind of Skinner Box that makes the coop dark when his birds exceed a certain volume. His crow sensor features a microphone and amplifier that puts out a digitized signal. A microcontroller monitors the signal, opening and closing window shutters as needed so that Matt gets his Z's.

Sleep late skinner box
Amt Part Description Allied Part #
1 Regulator, low-dropout 288-1194
1 Op amp, dual audio 288-1552
1 H-bridge, 3A, 55V 288-1572
1 Kit, resistor, metal film 296-1705
1 Terminal block, board mount 515-2008
1 Copper clad boards 661-0445
1 16 MHz microcontroller 671-0052
1 Solid state relays 788-0171
1 Serial connector 810-0816
1 Optoisolator, dual NPN transistor output 935-6358
1 Diode, small signal switching 950-1556

Additional parts required: enclosure and cover, resistors, capacitors, switching regulator, and amplifiers

Technical Description

Purpose: To train roosters to crow softly rather than at full volume!

Hypothesis: It has been observed that when the coop is kept dark the roosters do not crow very much if at all. I suspect that the roosters do not like darkness very much. Use this possibility to effect a change in the roosters behaviour.

Method: Make the coop dark when a rooster crows above a certain volume. A crow sensor consisting of a microphone and amplifier puts out a signal that is digitized by the on-board A/D converter of a microcontroller. The microcontroller monitors the magnitude and the zero-crossing rate of the digitized signal. It also keeps track of time. If it is daylight hours and a rooster crows and the volume is above the acceptable threshold the shutter is closed. The microcontroller is also responsible for maintaining extended light hours during winter by turning on the incandescent light when needed and must turn the light off and close the shutters when necessary. The zero crossing rate can be used to ignore other loud sources of noise such as thunder. For the prototype only magnitude will be used.

Other requirements: Log the number of crows in an hour and upload to a PC periodically to see if the crow rate or average crow magnitude changes over time.


1. Attached are two pdf files. The first, coop-ctrl-concept.pdf, is what I based the parts list on. However, I began to realize that there was far too much work for me to achieve in a reasonable amount of time and I havesimplified my design to the diagram in pdf number two, coop-simplified.pdf.

2. I probably need to add a photosensor so the device knows whether it is bright out or not.

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