How to troubleshoot electrical interference (noise)

Overview/Potential causes

The cause of electrical interference can vary.
Electrical interference may be caused by, but not limited to:

  • Electromagnetic interferences (EMI) or radio frequency interferences (RFI) caused by power leads or other machines (e.g. the drum rotor motor)
  • Voltage issues
  • Ground loops: caused by wattage issues within the electrical circuit
  • Grounded probes 
  • Broken probes
  • Broken port
  • Poorly isolated cables

Solution/Troubleshooting steps

  1. If you are roasting on a laptop, please take it off the electricity and see if the signal improves when roasting on battery mode only.
    This way ground loops as potential issues are getting ruled out.
  2. Follow the probe cable and check if there are touch points with other signal wires. Isolate the probe cable from other cables to rule out EMI or RFI. 
  3. Take out the probe from the roaster and hold it with your fingers, start the Cropster and touch the tip of the probe with your finger.
    If the spikes only appear when the finger touches the probe, we can assume the probe is broken. In this case, we recommend replacing the probe with a new ungrounded probe. 
  4. In some cases, the roaster (where the wall touches the probe) itself can introduce these interferences.
    An inexpensive action you can take is to isolate the probe with Teflon tape.
    📚 Learn how to isolate the probe
  5. If you connect through a Phidget, try attaching the Phidget to a different USB port. You can also add a USB isolator*. It is a small device you can put in between your Phidget and computer. In most cases, this also eliminates interference caused by ground loops.

* We recommend the Phidget 3060 device but any other device with similar specs can be used. 

If the issue can not be resolved by the recommendations above, please consult the roast machine manufacturer or an electrician.

Congratulations! You are now ready to troubleshoot electrical interference.

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