Calibration error

  • I am unable to calibrate my colorimeter. When I try to calibrate with a cuvette of water, I get the following error: RSP_ERROR: [0, calibration failed]

    When I try calibrating with the colorimeter empty and the slider open, I do not see the LEDs flash and I get this error: response from device is too short.

    Any troubleshooting ideas? Is it possible I assembled something incorrectly?

  • @chwang

    Check the cable connecting the light sensor board to the led board board and make sure that the orientation is correct i.e., that GND -> GND, red -> red, etc.

    Are you using the standard RGB LED board or one of the custom boards with 1 LED (board B ) or 2 LEDs (board C). In the later case make sure to select the correct mode from the drop down menu.

  • @Will-Dickson I have gotten it to work with board B but am still getting the RSP_ERROR: [0, calibration failed] error when I try calibrating with the standard RGB board, both with water and empty.

  • @Will-Dickson Also I am seeing the LEDs flash now but still getting the error

  • @Will-Dickson Actually I am seeing the LEDs flash irregularly - for a while I was seeing just the red flash when I clicked calibrate, and then when I clicked "ok" on the error message the blue would flash. After disconnecting and reconnecting, I am seeing nothing when I click calibrate and still the blue flash when I dismiss the error message. The wires are connecting the correct pins but I'll try reconnecting them so they are not twisted.

  • @chwang

    Another test which you can try is to expose the light sensor to light and then run the calibration procedure. Because the light sensor is exposed to light the calibration procedure should finish - it won't matter whether or not the LEDs flash. This will test the operation of the light sensor and firmware.

    You can expose the light sensor to room light by removing the top of the colorimeter enclosure. Make sure the light sensor is directly exposed to the room light. Then try running the calibration procedure. Do you still get the RSP_ERROR? Note, this won't result is a good calibration, but it will let us know if the light sensor is working and which will help us diagnose the problem.

  • @Will-Dickson I just tried this with both boards and am still getting the error. So maybe the sensor itself is not working properly?

  • @chwang

    Yes, it may indicate an issue with the sensor board, the connection to the sensor, or with the firmware.

    Do you get any error when initially connecting to the Arduino? After connecting what do you see in the "Samples" textbox? is it set to 500?

    If connecting to the Arduino works OK, but after trying to calibrate with the sensor in room light you get the error "unable to calibrate device: RSP_ERROR: [0, calibration failed]". This means the the Arduino is not able to read from the light sensor.

  • @Will-Dickson I have not experienced any issues connecting the Arduino, and the Samples box is set to 500. So as you say, it seems the problem could be with the sensor. However, I still do not reliably see the LEDs flash when I try to calibrate so could that indicate a different problem?

  • @Will-Dickson I was also thinking about ordering a second colorimeter kit to make it easier to use the two different LED boards without having to take it apart every time. So perhaps I could just order a full kit and swap out different parts to help diagnose the issue?

  • @chwang

    The LEDs not flashing could still be related to the sensor issue. The firmware cycles through the LEDs one at a time and measuring the frequency of the pulses coming from the light sensor - the frequency of these pulses is proportional to the light intensity. It measures the frequency (or period) for "Samples" number of pulses and then averages to get a get final measure of the frequency (and thus light intensity). If the Arduino isn't receiving the pulses the firmware will error out and so you won't cycle through to the next color. This could explain why you aren't seeing all the LED flashes. Also, you can slow down the LED flashes by increasing the "Samples" number, e.g., increasing "Samples" to 5000 will make the firmware try to measure 5000 pulses and average the results - this will take longer so the LED will remain illuminated for longer.

    We can send you a replacement sensor board, arduino shield and ribbon cable. This should cover the bases regarding the sensor unless it is an issue with the Arduino itself. I should be able to have the replacement parts in the mail to you by tomorrow.

  • @Will-Dickson Sounds good, thank you!

  • @Will-Dickson If I still want to order a second colorimeter, should I just put in that order separately?

  • Hi, yes, for a second order, just place a new order on the online store. We would ship a new order in 2-3 days.

Log in to reply