If you wish to avoid soldering, then I’d look at ready made alternatives, such as Z-Wave.
DIY wireless sensors, such as designs based on the ESP8266 are 1/4 the cost, but you do need some software and hardware skills. The learning process is more fun, IMHO.
I’ve used 1-Wire devices for many years, but to drive long lengths of wire (e.g. >10m), used dedicated host adaptors.
Many projects use Raspberry Pi IO pins to ‘bit-bang’ the 1-Wire protocol to DS18B20 which are VERY close to the Pi (e.g. 1-2m) and may only have one or two sensors. The CPU load of directly controlling IO pins is also much higher than relying on a dedicated hardware interface.
I have been testing a RPi2 with a DS9490R USB Host Adapter plugged directly into the Pi USB ports. As it is a dedicated interface, it can drive longer cable lengths and is simpler to use in software.
You can install owfs-server, configure with owfs-shell and link to OpenHAB with the onewire binding very quickly. It looks like ofws-server can use bit-bang IO interfaces via the Linux kernel driver, but I’ve not tried.
To avoid any soldering, the USB or dedicated Raspberry Pi interfaces and pre-made cabling can be bought from several sources, including:
This company illustrates the options to connect 1-Wire devices well - they offer:
- RPI1 - passive ‘bit-bang’ host adapter using kernel based 1-Wire drivers
- RPI2 - uses a dedicated Maxim DS2482-100 I2C to 1-Wire IC
- RPI3 - uses a larger dedicated Maxim DS2482-800 8 channel I2C to 1-Wire IC
Their pictures of the PCBs show the difference in complexity between a IO pin interface, and a dedicated interface chip.
Note: most 1-Wire sensors (like the DS18B20) are bus powered, so need two wires - 0V and Data. Some 1-Wire devices need additional power (e.g. switches, humidity sensors, etc) so add 5V or 3.3V giving three wires.
The DS18B20 device and sealed probes on eBay have three wires, but two are usually connected together in use (parasitic power mode).