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NOTE: CrowBox 2.0 is still in iterative development. This document follows the progress that occurs on the physical design. Items listed here may appear and disappear as the design progresses, until the first release when it is finalized.


With explanation of duty/role. Experimentally grouped by component type.

Notes on cost:

  • If only one of a given part is required per CrowBox, only one cost (cost per unit) will be listed for that part.
  • If each CrowBox requires more than one of any given part, then the Cost per CrowBox will also appear.


The CrowBox system CPU.

  • Arduino Mega2560 R3
    • Overall, the decision to use Arduino is Legacy
    • Mega2560 chosen mainly for its proliferation of I/O pins
  • Cost per unit
    • Genuine Arduino- $35.34
    • Arduino Compatible (Ximico) - $17.99


For ease of assembly and maintenance, CrowBox circuits are assembled on tiny 170-point breadboards.

  • Cost per unit: $1.33
  • Cost per CrowBox: $4.00


NOTE This pricing is based on buying six-packs of these breadboards on Amazon Prime. Surely we can find better pricing in quantity direct from China. And don't call me Shirley.

Cables, Wires & Connectors

Breadboard Jumpers

Used for low-profile wiring of the circuits which are assembled on the miniature breadboards.

  • Cost per unit: $6.50


Dupont Cable

Used for many electrical connections within the CrowBox. Dupont cable kits come in 'ribbons' of multiple connected cables. These can be easily separated into custom cables with the required number of conductors. Color-coded insulation makes assembly instructions easy to follow.


Sensor Packages/Shields

SD Card Module

Off-the-shelf Arduino shield which provides SD card access.

  • SainSmart micro SD storage module
  • Cost per unit: $8.00


Micro SD Card

FIXME - Are we to include an SD card with the kit?


CrowBox 2.0 requires two gearmotors: One to operate the coin dispenser and one to operate the reward dispenser.

Reward Dispenser Motor

  • Mabuchi 12V 2RPM gearmotor
  • Cost per unit: $13.00


Coin Dispenser Motor

  • Mabuchi 12V 7RPM gearmotor
  • Cost per unit: $13.50


We should find a cheaper source for these motors. Alibaba or something.

We may need to source a motor with higher RPM - or gear them up


Training Phase Selector

This button permits the CrowBox operator to select which phase of the training protocol is currently being observed.

  • 12mm x 12mm SPST PCB normally-open momentary pushbutton
  • Cost per unit: 45 cents


Rocker Switch

This is the main power switch for the CrowBox.

NOTE: We plan to install the power switch inside the CrowBox to guard against tampering therefore a weatherproof switch is not required.

  • Rocker Switch: B00AKVBEN6
  • Cost per unit: 50 cents


Lever Switch

This switch interfaces with the cam on the perch armature to detect bird arrival and departure.

  • Lever Switch: V-156-1C25
    • Normally OPEN
    • Any long-lever-with-roller switch will work.
  • Cost per unit: 72 cents



A total of four LEDs are required for each CrowBox- these are used to indicate which training phase is currently activate (one, two, three or four).

  • Any 3.0 to 3.6 volt LED will do.
  • Cost per unit: 5 cents
  • Cost per CrowBox: 20 cents


Optical Sensors

Three instances of the same optical sensor circuit are used in each CrowBox:

  • One watches to ensure the Reward Dispenser actually dispenses
  • One watches to ensure the Training Coin Dispenser actually dispenses
  • One watches for any coins deposited by birds

The main component in each of these sensor circuits is the TCRT5000 reflective optical sensor.

  • Cost per unit: 54 cents
  • Cost per CrowBox: $1.62



FIXME - This was done in a hurry. VERIFY these, Steve.

220 ohm

  • (3) current limiting resistor for IR LED's in all three TCRT5000 packages

10,000 ohm

  • (1) current limiting resistor for the training LED's
  • (3) pulldown resistor for each transistor in the three TCRT5000 packages
  • (2) current limiting resistor to BASE of (FIXME - model number) Motor Switching Transistors

100,000 ohm

  • (2) R2 resistor in both Motor Switching Circuits


Debouncing Capacitors

These capacitors are used to 'debounce' button inputs, ensuring we get smooth and reliable state changes.

  • .FIXME (need capacitance rating) mylar/polyester film capacitor
  • TWO are required
  • Cost per CrowBox: FIXME

Noise Reduction Capacitors

These capacitors are used to smooth voltage passing through out motor coils.



Allows the Arduino's 5 volt output to switch current to the 12 volt loads (motors)

  • Two 2N3904 transistors - 12v switching
  • Cost per unit: $1.20
  • Cost per CrowBox: $2.40
  • NOTE: These are Radio Shack prices. Easy to beat online in quantity.


Used in various circuits throughout the CrowBox, grouped by role.

Current Protection

These diodes are used to protect CrowBox circuitry against 'backlash' current from the motors.



Parts making up the framing, housing and support members of the CrowBox.

  • 1/8“ Baltic Birch plywood

Fasteners & Hardware

Mechanical fasteners - nails, bolts, screws, clips, etc.

Cabinet Lock

Provides basic security against tampering and vandalism.

  • Cost per unit: $5.00


Adhesives & Coatings

Glues, paints, sealants.

  • Gorilla wood glue
  • High-temperature hot glue sticks


Included with Kit


  • High-temperature hot glue gun
kit/bill_of_materials.txt · Last modified: 2018/08/01 13:37 (external edit)