Designator	Component	#	Cost/unit USD	Total cost	Source of materials
RespiCo breadboard -
U1	HUZZAH32 – Esp32-WROOM-32 Feather Board	1	$19.95	$19.95	Adafruit 3405
Female headers	Feather female header set	1	$0.95	$0.95	Adafruit 2886
Breadboard	breadboard	1	$5.95	$5.95	Adafruit 239
Jumper wires	Male/male jumper wire set	1	$3.95	$3.95	Adafruit 759
USB cable	USB A-plug to Micro-USB data cable	1	$4.95	$4.95	Adafruit 2185
Wire	22 AWG flexible 2 conductor wire	3′	$0.60/ft	$1.80	Tuofeng 12AWGAmazon ASIN B0981NF1HV
SW_SPST	SPST slide switch	1	$0.95	$0.95	Adadruit 805
CONN_1x3	1 × 3 male header pins	3	$4.95 / 360	$0.04	Adafruit 392
R1	1 kOhm, 1/8 W, +/- 5 % value	1	$0.01	$0.01	Ltvystore LYSB01MDJQ1II-CMPTRACCSAmazon ASIN B01MDJQ1II
R2	75 Ohm, 1/8 W, +/- 5 % value	1	$0.01	$0.01
R3	15 Ohm, 1/8 W, +/- 5 % value	1	$0.01	$0.01
R4	51 Ohm, 1/8 W, +/- 5 % value	1	$0.01	$0.01
R5	68 Ohm, 1/8 W, +/- 5 % value	1	$0.01	$0.01
JST-XH	Male and female connectors	2	$0.03	$0.06	IZOKEE IZKEGB11-USAmazon ASIN B0791DJMW9
Y1	Passive piezo-electric buzzer	1	$1.06	$1.06	Uxcell a15091400ux0103Amazon ASIN B018I1WBNQ
D2	Diffuse output RGB common anode LED	1	$0.50	$0.50	FEDY FD-5WSRGB-A Adafruit 302
ERM Motor_DC	Brushless, eccentric rotating mass motor	1	$1.40	$1.40	uxcell A14061100ux0057Amazon ASN B00PZYMCT8
D1	1 N4001 flyback diode	1	$0.15	$0.15	Adafruit 755
Q1	PN2222A NPN bipolar transistor	1	$0.20	$0.20	Adafruit 756
Battery	Lithium-ion polymer battery, 400mAh	1	$6.95	$6.95	Adafruit 3898
RespiCo prototype, additional components -
Custom circuit board	FeatherWing proto, includes loose male headers	1	$4.95	$4.95	Adafruit 2884
CONN_1x3	1 × 3 male header pins	3	$4.95 / 360	$0.04	Adafruit 392
SW_tactile	Tactile switch button	1	$4.95 / 20	$0.25	Adafruit 1489