This is an easy to build, very compact, and low profile Arduino compatible platform to build a humidity meter/Gauge using a 0.96Inch OLED display. The project consists of Atmega328 microcontroller, 0.96Inch OLED display, 3.3V regulator, and HIH5030 analog humidity sensor from Honeywell. The HIH5030 sensor provides an analog voltage output, the analog voltage is near linear voltage output vs %RH, the sensor output is connected to A0 (Arduino-ADC pin 0) of the ATmega328 microcontroller. The sensor output is 0.25V to 2.5V vs 0 to 100% RH. Connector CN2 is provided for boot-loader flashing and Arduino programming. Use Pin 4 GND and Pin5 VCC to power the project.
Humidity Meter Using OLED Display – Arduino Compatible – [Link]