Getting access to 1-Wire devices

To show you how the 1-Wire bus works, we can use a really simple chip: the temperature sensor chip DS18B20. There are two possible ways or modes by which the chip can be powered: a parasite version (that is, which works in the parasite mode), with two wires only, and a normal version with a dedicated power pin, which uses the three wires instead.

In this example, I'm going to use the three wire's waterproof version of this chip, which implements a special packaging of the chip that can be used in hostile environments (see the following figure for the images of the two chip's packaging version):

Note

The device can be purchased at (or by surfing the Internet) http://www.cosino.io/product/waterproof-temperature-sensor.

First of all, we've to set up the electrical connections. In the following table, the correspondence between the BeagleBone Black's pins and the sensor's cables is reported:

BeagleBone Black pins – label	Sensor cables – Color / Standard case pin...