Darktimer Bill of Materials

Mouser Project shopping link: Dangerpants Labs Darktimer v1.0 Shopping List* -- use this link to quickly purchase all of the components necessary to build a Darktimer

Integrated circuits, active devices:

Quantity ID Name Notes Approx. cost
1 Arduino Arduino Pro Mini 5v Microcontroller board $5-10
1 LCD1 16x2 character LCD Any HD44780-based LCD will work. Firmware assumes 16x2. $5

Mechanical components:

Quantity ID Name Notes Approx. cost
1 Case Any suitable case Varies
3 NEXT, PLUS, MINUS SPST Momentary switch Any type, per your requirements Varies
1 GO SPST Momentary Switch Should feel different from other switches Varies
1 Power SPST slide switch Non-momentary Varies
1 Battery 3-4 cell AA or AAA holder Use a 3 cell holder for alkaline cells, or 4 cell for NiMH cells Varies

Passive components:

Quantity ID Name Notes Approx. cost
1 Speaker Small speaker Coil or piezo Varies, typically under $10
1 R1 100 ohm Speaker limiting resistor $0.10
1 R2 10 kΩ trimmer LCD contrast adjustment $0.50

* Note that the parts in this list were chosen to suit one particular build. You are strongly encouraged to use this as a starting point, and modify the LCD, switches, battery holder and case to suit your own needs.