- The DHT22 is a more accurate sensor, and it is capable of sensing a greater range of temperatures and humanities.
- The external pull-up resistor is optional because our Raspberry Pi can use its internal embedded pull-up resistor.
- An LDR is a light-sensitive resistor. When used as part of a voltage-divider circuit, we turn the varying resistance into a varying voltage. This voltage can then be detected by an analog-to-digital converter such as the ADS1115, which is connected to your Raspberry Pi.
- Try varying the resistance of the fixed resistor in the voltage-divider circuit. Try higher-value resistances to make the LDR more sensitive in darker conditions. Try lower-resistance values to make the LDR more sensitive to brighter conditions.
- No two LDRs are identical when it comes to the resistances they measure. If you swap out an LDR in a circuit, re-calibrate the code just to be sure.
- Water conducts electricity. It acts as a resistor between the two probe wires...