SHT21-tester Wiring - I2C Mikrokontróler SHT21 2.1-3.6V Vcc GND GND (Hardware SDA) SDA (Hardware SCL) SCL Datasheet Datasheet SHT21: http://www.farnell.com/datasheets/1780639.pdf Buy at Aliexpress: Sensor SHT21 in Si7021 Module: https://www.aliexpress.com/item/32609693018.html?spm=2114.search0104.3.15.78323b5aU5wdDE&ws_ab_test=searchweb0_0%2Csearchweb201602_1_10065_10068_319_10059_10884_317_10887_10696_321_322_10084_453_10083_454_10103_10618_10307_10820_10821_10303_537_536%2Csearchweb201603_52%2CppcSwitch_0&algo_expid=ce07671d-9838-45ed-a6d6-3fbbe9f56285-2&algo_pvid=ce07671d-9838-45ed-a6d6-3fbbe9f56285&transAbTest=ae803_5