Code

https://github.com/liutyi/arduino-humidity-sensors-test/blob/master/humidity-sensor-tester-v2.ino

Screen

Sensor map

-A mean Adafruit sensor

BME680-2 - GY-MCU680 with STM MCU on board

Serial plotter example

Hardware

Project components cost

Main Unit hardware

Keyestudio Super Mega 2560 R3 Advanced 16$

3.5 inch TFT LCD screen module Ultra HD 320X480 9.5$

OOTDTY 125x83x32mm Black Waterproof Box 3.5$

4 channel IIC I2C Logic Level Converter Bi-Directional Module 5V to 3.3V  2$ for 10pcs + delivery

Pololu 5V Step-Up Voltage Regulator U1V10F5 4$ (arduino.ua) 

AMS1117 4.5-7V Turn 3.3V DC-DC Step Down Power Supply Module 0.5$ (arduino.ua)

TZT type-c USB 5V 1A 18650 TP4056 Lithium Battery Charger Module 0.8$

2500mAh Li-Pol 505378LP battery unprotected ~5$

SD Card 8GB ~5$

Sensor board hardware

Multiplexors board

TCA9548A I2C Multiplexer Breakout board for chaining Modules 3x3$

SHT85 pin converter

Adapter board 1.27MM 2.0MM 2.54MM 8/12 pin 6.3$ for 20pcs

1.27mm Pin Header Single Row Female 4 pin 1$

1.27mm Pin Header Single Row Female 40 pin 2$

One Roll 8 Colors 30AWG Wire Wrapping Wire, Tinned Copper Solid 4.2$

M3 Nylon Black Hex M-F Spacers/ Screws/ Nuts Assorted Kit 4$

9*15 Double Side Prototype PCB Board 2x3$

5x7 4x6 3x7 2x8 cm double Side Prototype PCB Board 2$ for 4 pcs

Sensors

Si7021 2x2$ 2x3.2$ 1x10$ 1x3.5$

BME280 3x2.1$

DHT12 3x 1.1$

SHT20 3x3.3$

CJMCU-SHT21 3x10$

CJMCU-HDC1080 3x4$

GY-213V-HDC1080 3x2$

SHT25 8.5$ + board

SHT30 2x6.5$

SHT31 2x8.5$

SHT31-2 1x7$ 3x3.5$

SHT35 2x17$

AHT10 8x 1.12$

AM2320 5x 1.5$

BME680 2x10.65$

MCU680 2x10.70$

SHT85 3x30$ + delivery

Project v3 components approximate total cost: 700$