CO2 Guard: A DIY Approach to Monitoring Air Quality
Materials
Build This Project
Bring this design to life with the Elektor PCB Service, powered by Eurocircuits. Upload the project files and order professionally manufactured PCBs or assembled boards through a proven European production platform.
Supporting KiCad, Eagle, Gerber, and ODB++ formats, the service is suitable for everything from prototypes and validation builds to series production and volume manufacturing.
Made in Europe. Fast. Reliable. Professional.
Bill of Materials
Component List
Resistors
R1,R2,R3 = 330 Ω, 0.25 W, 5 %
R4 = 4.7 kΩ, 0.25 W, 5 %
R5 = 0 Ω, place wire, see text
R6 = 0 Ω, place wire for 5 V or leave open, see text
R7 = 1.5 kΩ, 0.25 W, 5 %
Capacitors
C1,C2 = 100 nF, 50 V, 10 %, X7R, lead spacing 5 mm
C3 = 100 µF, 25 V, optional , not mounted, see text
Semiconductors
D1 = BAT85, DO-35
T1 = BC327, PNP, TO-92
LED1 = LED red, 5 mm
LED2 = LED yellow, 5 mm
LED3 = LED green, 5 mm
Other
MOD1 = 1x10 SIL header, female, split in 1x4 and 1x5 (see Text)
MOD1 = MH-Z19C, version 400-5000 ppm, pins on bottom
MOD2 = Wemos D1 mini with 2x 1x8 SIL header
S1 = switch with built-in LED (momentary on, self-reset, blue circle)
Enclosure PP73BL, Supertronic
BZ1 = DC buzzer, 5 V, pitch 5 or 7.62 mm, diam. 14 mm max
heat shrink tube, I.D 2.4 mm, 20 cm
LED housing, for 5 mm LED (LED1..3), Black
FAN 5 VDC, 30x30x10.5 mm
12-pin male SIL header
PCB 210043-1 v2.0
Thin stranded wire to connect LEDs and switch:
stranded wire, 0.25 mm2, black (2x8.5+12 cm)
stranded wire, 0.25 mm2, red (8.5+12 cm)
stranded wire, 0.25 mm2, yellow (12 cm)
stranded wire, 0.25 mm2, green (12 cm)
stranded wire, 0.25 mm2, blue (8.5 cm)
Discussion (0 comments)