“Draw an Arduino Uno circuit with a DHT22 sensor and 10 kΩ pull-up resistor, plus a 16x2 I2C LCD connected on SDA and SCL, powered from 5 V.”
Comprenez les décisions qui le sous-tendent.
Add the required data pull-up resistor.
Use SDA and SCL for the I2C display.
Decouple the shared 5 V rail.
Use for a simple Arduino temperature and humidity monitor.
Questions fréquentes
Why does the DHT22 need a pull-up?
Its single-wire data line needs a resistor to hold the line high when no device is actively pulling it low.
What pins does I2C use?
I2C uses SDA for data and SCL for clock, connected to the board’s corresponding pins.
Can the display and sensor share 5 V?
Yes, provided the supply can safely provide their combined current and all grounds are connected.