Yocto-Thermocouple (J/K/E/T/N type thermocouples) - Roasting Intelligence (RI) Setup (beta)

This manual covers the hardware connection, software installation and settings of Cropster’s Roasting Intelligence for J/K/E/T/N type (UNGROUNDED) thermocouples, connected via a Yocto-Thermocouple device.

If you haven't been invited to participate in the beta program for this integration, but you are interested in participating and testing the feature, please sign up here.

Beta means that the features are being tested with a select group of users to help us identify minor flaws under everyday conditions that we cannot reproduce internally. Therefore, it will be necessary that you share feedback with us and let us know whenever you come across some unexpected behavior.

Note: We recommend reviewing the Yocto-Thermocuple's User's guide, before proceeding with the steps provided in this article.

Legal Note

Please read this installation and configuration guide carefully, as any mishandling could lead to permanent device damage.

By connecting a data bridge/board, or temperature probe to any computer, or by installing Cropster’s Roasting Intelligence (RI) software, the user agrees to release Cropster from any liability and assumes any possible risk related to the use of this measuring device and/or software. Cropster's terms of service apply.

Yocto-Thermocouple contents

Yoctopuce's Yocto-Thermocouple.

Note: The USB 2.0 Type-A to Micro-B data cable, shown in the picture above, is sold separately from the Yocto-Thermocouple device.

We recommend ungrounded thermocouples type K, J, T, E, or N.



As shared by Yoctopuce, the Yocto-Thermocouple device requires a USB 2.0 Type-A to Micro-B cable with data connectivity, for a connection to a computer. Make sure not to buy a simple USB charging cable without data connectivity. The supported cable type is available from the Yoctopuce shop.

Connection options

Depending on the type of your roaster and thermocouples, there are two connection options: 

Direct connection

A direct connection applies when adding new probes independently from the roaster's readout. The newly added probe can be connected directly to the Yocto-Thermocouple device.

Proceed with the Yocto-Thermocouple Device Installation.

Dual connection

A dual connection applies when the roaster is equipped with a dual probe. A dual probe is a probe with two sensors inside the hull and two pairs of wires that allow a simultaneous connection to the Yocto-Thermocouple, and the roast machine's readout.

If your machine has single probes, you may replace the probes by dual ones, to allow for a dual connection.

Proceed with the Yocto-Thermocouple Device Installation.

Yocto-Thermocouple Device Installation

Disconnect the USB cable from the Yocto-Thermocouple device and turn off your roast machine during the hardware installation.

Yoctopuce does not recommend connecting USB devices through two cascaded (interconnected) hubs without an external power supply. In order to cascade hubs, it is necessary to use self-powered USB hubs, that provide a full 500mA to each support. Learn more about USB power distribution from Yoctopuce's User's Guide.

  1. Follow the probe cable from the tip of the probe to its end, where the two wires appear.
    In case of dual probes, take the free end that is not connected to the roast machine.
  2. Connect the two wires from the probe, by polarity, to any channel of the Yocto-Thermocouple device with a screwdriver, as shown in the table below. Refer to the Yocto-Thermocouple's ports, for the +/- symbols.
  3. Connect the Yocto-Thermocouple device to the computer with a USB-A cable and proceed with the Roasting Intelligence Setup.
 EURO-standard US-standard


  • Green wire to the positive (+) port.
  • White wire to corresponding negative (-) port.

  • Yellow wire to the positive (+) port.
  • Red wire to corresponding negative (-) port.

  • Black wire to the positive (+) port.
  • White wire to corresponding negative (-) port.

J -type
  • White wire to positive (+) port.
  • Red wire to corresponding negative (-) port.

    Roasting Intelligence (RI) Setup

    Installing the Roasting Intelligence (RI) software

    1. Download the Roasting Intelligence from https://download-beta.cropster.com/
    2. The Cropster installer leads you through all the installation steps.
    3. Open the RI by double-clicking the Cropster icon on the desktop.
    4. Enter your username and password.
      The username is the email address your Cropster invitation has been sent to, and use the password you've generated when accepting the invitation.
    5. Check the Remember credentials box if you want to be able to run the RI offline.
    6. Click the Login button.


    Establishing a connection to the machine

    1. Go to Account > Preferences > Machine tab.
    2. Select the Roast machine you would like to connect from the Machine drop-down menu.
    3. Select Yocto-Thermocouple from the drop-down menu for all measurements connected to the Yocto-Thermocouple device.
    4. Select the Channel.
      The channel refers to the ports on the Yocto-Thermocouple device.

      Yocto-Thermocouple schematic, available from the Yocto-Thermocouple User's guide. 
    5. Select the Type of thermocouple.
    6. (optional) Click the toggle button to turn on (or off) the Rate of Rise (RoR) curve for your measurements.
      Learn how to set the RoR within the RI.
    7. Click Save to confirm the changes. The RI requires a restart to apply the settings.

    If the setup was successful, you will be able to see temperature values on the right-hand side of the RI screen, after the restart.

    Learn to customize your RI user preferences


    If the RI indicates No source connected and/or you cannot see any measurements, please check the following: 

    • Is the Yocto-Thermocouple device connected to the computer?
    • Are the thermocouples connected to the Yocto-Thermocouple device?
    • If your Yocto-Thermocouple is connected by USB, and its blue LED is on, but if the operating system cannot see the module, check that you are using a true USB cable with data wires, and not a charging cable. Find the appropriate cable from the Yoctopuce shop.

    If Roasting Intelligence shows negative temperature readings, you will have to swap the wires on the board from the positive (+) port, to the negative (-) port, and the other way round.

    Erratic temperature curves (electrical interference)

    An erratic, or noisy temperature curve, is a common issue in PC-based, temperature-logging systems, and can originate from different sources:

    • Sensor noise
    • Signal wire noise
    • Ground loops
    • etc.

    The Yocto-Thermocouple, is not an electrically isolated module; there is no electric separation between the measuring part, and the USB part. This has consequences, as explained by Yoctopuce's article "The Yocto-Thermocouple and ground loops".

    For further assistance, please create a support ticket by clicking the Support button in the left lower corner of the app. A Cropster support rep will get in touch with you.

    Congratulations! You have successfully set up the Cropster Roasting Intelligence!

    Check out our Getting started video and enjoy tracking your first roasts! 

    More manuals and videos can be found on help.cropster.com.