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.