Wire two Dallas ds18b20

[DMendoza]

Hi, I would like to know if the libraries of the Dallas sensors are compatible to be able to connect in a wire two dallas ds18b20

[dennis650]

Hi,

yes. OneWire is a bus. I have 4 DS18B20 in row, one DS2438 and a DS2406P on just one ESP32 GPIO. The OneWire Devices have different adresses.

Greetings
Dennis

[DMendoza]

Thank you

[kusumy]

hi @dennis650, can you share an esp32 library to access DS2438 ?
Thank you

[JacktheRipper]

I have been using an Adafruit HAZZAH ESP32 connected to three ds18b20 sensors. They are connected in parallel, and I use the standard DallasTemperature.h Arduino library. When connected as a full three-wire sensors (separate GND, 3.2V and signal wires) they work perfectly. When connected using the two-wire approach (sensor GND and VXX shorted together at the sensor connected to GND at the ESP32, and a signal wire) they don't work. Either they are very inaccurate, or they return nothing. This two-wire configuration has worked fine for me at 5.5v with both a UNO and a Nano. Must include the 4.7k pullup resistor to the signal pin.

[Edje11]

You have to en bale the parasit power mode for the ds18b20 in Arduino.