1-Wire Devices

1-Wire

1-Wire is a device communications bus system that provides low-speed data, signaling, and power over a single conductor.

UniPi tries to maximize the reliability of the whole network by serializing the bus as much as possible. This is achieved by using 4 wires (GND, VCC, Data-IN, Data-OUT). This four-wire design is used in our 1Wire temperature sensors and 8port hubs.

The DS18B20 is widely used 1-Wire sensor in TO-92 package.

  • Power supply range is 3.0V to 5.5V
  • Measures temperatures from -55°C to +125°C (-67°F to +257°F)
  • ±0.5°C accuracy from -10°C to +85°C
  • Converts 12-bit temperature to digital word in 750 ms (max.)
  • Can be powered from data l

UniPi 1-wire temperature sensor

The Unipi 1-Wire temperature sensor is equipped with RJ45 connector, so it is easy to connect to the older variants of Unipi Neuron controllers or the UniPi 1-Wire hub. The newer variant of Unipi Neuron PLCs and the Unipi Axon product line both use a 3-wire screw terminal which does not support the RJ45 connector. To connect the 1-Wire temperature sensor to Axon or Neuron controllers, you can use two methods

  1. cut off the sensor's RJ45 connector, put ferrules on the conductors and screw them into a screw terminal connector included in the controller's package following this pin-out scheme

The sensor introduces a 4 wire connection for better reliability of larger network, which can be converted to 3 wire version for simplification.

Connecting a single 1-Wire sensor to the Unipi controller

Connecting a pair of 1-Wire sensors to the Unipi controller via RJ45 splitter

Connecting multiple 1-Wire sensors through a 1-Wire hub

Creating a multi-hub extensive network of 1-Wire sensors