The DS18S20 has an accuracy of ±0.5°C from -10°C to +85°C, and ±1°C from -55°C to -10°C and +85°C to +125°C.
You can connect multiple DS18S20 sensors to a single bus by connecting the VDD, GND, and DQ pins of each sensor in parallel. Each sensor has a unique 64-bit ROM code that allows the master device to address and read the temperature data from each sensor individually.
The maximum cable length for the DS18S20 is approximately 100 meters, but this can be affected by the quality of the cable, the noise environment, and the bus speed. It's recommended to use a twisted pair cable with a shield to minimize noise and ensure reliable communication.
In parasite power mode, the DS18S20 derives its power from the data line. To handle this mode, you need to ensure that the data line is pulled high to VCC through a resistor (typically 4.7kΩ) and that the master device provides a strong pull-up to maintain the voltage level. You should also avoid using a pull-down resistor on the data line.
The conversion time for the DS18S20 is approximately 750ms for a 12-bit temperature reading, 375ms for a 11-bit reading, and 187.5ms for a 9-bit reading. The conversion time can be affected by the bus speed and the number of sensors on the bus.
