1-Wire Basics

Setting up a 1-Wire network is quite straightforward. If you have read much about it, you probably already know what it takes. For those of you who are relatively new to the fine hobby of 1-Wire monitoring and automation, read on.

Firstly, let’s take a look at what 1-Wire is and what you can do with it. 1-Wire is really just a simple system of devices such as weather monitoring devices, garden monitoring devices, or home automation devices that are connected through a 1-Wire network to a computer (or other controller – more on that later). Your computer then receives signals from the devices, allowing you to track rainfall, temperature, humidity, soil moisture levels, lightning, and a host of other information.

So how does it work? Well, a 1-Wire network consists of a master controller which is connected to one or many slave devices. The master controller is typically a computer or microcontroller with an external 1-Wire interface such as our Serial Adaptor or USB Adaptor. All of the actual monitoring devices (lightning detector, moisture meter, motion detector, barometer, etc.) are slave devices. The master communicates with one or more slave device(s) using the serial 1-Wire protocol developed by Dallas Semiconductor, sending and receiving signals over a single data line plus ground reference. The 1-Wire protocol synchronizes the slave devices to the master. The master initiates and controls all activities on the 1-Wire network.

One key feature of the Dallas system is that every 1-Wire slave device has a guaranteed unique address that is realized as laser engraved on-chip ROM (Read Only Memory). This enables the master to individually recognize each of your slave devices, and means you can have multiple devices of the same type on the same network without conflict.