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I am looking to create a complete temperature humidity sensor system with 72 DS18B20 sensors. I am aware that each sensor receives it's own unique identifier and you are able to daisy chain them together. The problem that I am running into is that I am unable to find any DS18B20's that come pre-wired with either a RJ-11 or RJ-45 or similar output. Any recommendations on simplifying the sensors so that I can connect up to 72 or more sensors without having to crimp.

Closest part I could find is: https://www.dx.com/p/waterproof-ds18b20-temperature-sensor-with-adapter-module-for-arduino-2068262?tc=USD&ta=US&gclid=CjwKCAjwtajrBRBVEiwA8w2Q8M3cT5tqq_wZDYELYFuKgjfEyXfyiOpyokeLUyEyx4vutvJ4mRPJchoCsIsQAvD_BwE#.XWp31lNKjdQ

Unfortunately it seems the break out board with the step-up resistor only takes in one sensor. I'm unaware how I would have several put together.

Any recommendations would be appreciated.

Philoxopher
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(1) I am not sure if you can daisy chain 72 DS18B20s using only one Rpi GPIO pin. My experience is that it is OK connecting 16 sensors to one GPIO pin and so 64 sensors on 4 pins. You need to remove the pull up resistor on all except one module on one bus. But even so, too many sensors on one 1-Wire bus still seems not very stable. You might like to see my sensor wiring photos and a fully debugged python 3.7.3 testing program:

Connecting 64 DS18B20 Sensors

(2) My DS18B20s are prewired to a popular cheapie 3 pin keyed connector, so you don't need to do any RJ11 style crimping. You need to DIY simple signal routing breakouts to do star or daisy chain connections.

(3) I have tested my config for Rpi3B+ and also Rp4B, but with wires only about 60 cm long. I have not tested daisy chaining too many devices. I read that you need to use CAT5 like twisted pair cable for very long wires. You may find references in my answer manufacturer's app notes on what extenders and buffers to use for very long wires.

(4) So far I only found one driver, python3-w1ThermSensor-1.0.5 good for Rpi3B+ and Rpi4B. Many other old drivers are for jessie only and do not work for stretch or buster.

tlfong01
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