0405-01 Temperature Logger

Example Projects > 0405 OWFS 1-Wire > 0405-01 Temperature Logger

Temperature data logger using DS18B20 1-Wire sensors

This folder contains the source files for the demonstration project on building a temperature logger with REXYGEN.

This example can be used with any platform which supports 1-Wire bus (UniPi v1.1 Monarco HAT, Pigeon PLC, etc.). Four individual 1-Wire sensors (DS18B20) are assumed.

The measured temperatures are stored in the TRND blocks which allow displaying of the trends (graphs) in REXYGEN Studio or REXYGEN Diagnostics.

The data resides in RAM memory only. If you wish to archive it on a permanent storage medium, see e.g. example 0201-23.

Timing of the project

The algorithm runs each 500 milliseconds (0.5 s). See the EXEC function block,
tick x ntick0 = 0.05 x 10 = 0.5


  • REXYGEN Runtime Core must be installed and running on the device.
  • Owserver (part of the OWFS package) must be installed, correctly configured and running on the device.

Running the example

  • The *exec.mdl file is the project main file, open it with REXYGEN Studio.
  • Specify the 64-bit ROM IDs of the attached temperature sensors. See the 1-Wire driver manual below for details.
  • Compile and download the project to the target device.
  • Switch to Watch mode and observe the algorithm. The displays show temperature in real time, time plots are available upon double-clicking the TRND blocks.
  • You can watch any signal in real time, just select a block and pick Watch Selection in context menu (right-click the block).

User interface (HMI)

The example is accompanied by a HTML5-based user interface built on the WebBuDi framework (Web Buttons and Displays). There is also a WebWatch HMI generated directly from REXYGEN Studio.

  • Open web-browser and fill in the IP address of your target device and port 8008 (e.g.
  • Log in. Use the same credentials as for downloading the project (default login: admin, blank password).


Additional information