Hardware setup

Hardware setup

Connections

• The sensor using I2C bus, SDA and SCL pins must be pulled up via 10K resistors from 3.3V according to iAQ Core C's datasheet! See schematic below!

• I2C bus pins on ESP12E/F boards are GPIO5 - SCL and GPIO4 - SDA. If you are using Wemos D1 mini, I2C pins are SCL - D1 and SDA - D2!

• This sensor also has an option for resetting to factory default. Long pressing for 10 seconds a button connected to GPIO0 and GND will reset the sensor!

• DHT22 sensor's data pin is connected to GPIO12 (Wemos D6) via 4.7K pullup resistor from 3.3V!

Schematic

PCB design

Prefix	Value	Package
R1	10K Ω	SMD 0805
R2	10K Ω	SMD 0805
R3	4.7K Ω	SMD 0805
R4	10K Ω	SMD 0805
R5	10K Ω	SMD 0805
C1	100nF	SMD 0805
C2	10uF	SMD 0805
C3	10uF	SMD 0805
C4	100nF	SMD 0805
C5	100nF	SMD 0805
D1	SS14	SOD123
IC1	AMS1117-3.3	SOT223
Reset	Tactile 90 degree button	SMD 3x6x3.5mm
Serial	2.54mm 4P header	(optional)
H1	5V power	old microUSB female cable

---