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Home Online Store Information / Shipping 1-Wire Host Adapters Sensor Modules 1-Wire ICs Misc Components Cables and Connectors Product/Module Information SWE0 Sensor SWE1 Module SWE2 Module SWE2a Module SWE3 Module SWE4 Module SWE5 Module SWE6 Module RPI1 Host Adapter RPI2v1 Host Adapter RPI2v2 Host Adapter RPI3 Host Adapter 1-Wire Information 1-Wire Network Basics Wiring Information Raspberry Pi

RPI1 Software Details The RPI1 is designed to work with the 1-Wire driver built into the Linux kernel. To get it to work you need to ensure you have a kernel with the w1_gpio module in it. Most of the kernels available for the Raspberry Pi have this support already built in. To load the modules required do the following: pi@raspi:~$ sudo modprobe w1_gpio pi@raspi:~$ sudo modprobe w1_therm pi@raspi:~$ You should then be able to do the following: pi@raspi:~$ ls /sys/bus/w1/devices 28-000004184bfb 28-000004186eb3 w1_bus_master1 28-000004184dc3 28-000004193944 pi@raspi:~$ The four directories starting with 28- in this example are four DS18B20 temperature sensors. To read the temperature from one of the sensors you can do the following: pi@raspi:~$ cat /sys/bus/w1/devices/28-000004193944/w1_slave 2d 01 4b 46 7f ff 03 10 39 : crc=39 YES 2d 01 4b 46 7f ff 03 10 39 t=18812 pi@raspi:~$ In this example the temperature being reported by that sensor is 18.812C. When writing software to read this data it is recommended to check the crc gives a "YES" response or sanity check the value is within the expected range (or both) before accepting it as you do sometimes get readings that are way out.

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