Pulse-generating Hall-E sensor / sparklab FTS



  • Another, longer test print results in

    M591 D0
    Pulse-type filament monitor on endstop input 3, disabled, sensitivity 5.00mm/pulse, allowed movement 50% to 150%, check every 4.8mm, current position 0.0, measured sensitivity 2132.568mm/pulse, measured minimum 0%, maximum 87% over 4265.1mm
    

  • administrators

    Could it be that the sink current of the Hall sensor isn't sufficient to pull the endstop pin close enough to 0V, so most of the pulses don't get registered by the Duet?

    What happens if you increase the sample distance from 4.8mm to e.g. 50mm or 100mm? Obviously that isn't practical for real use, but it would help to pin down whether there is a firmware issue when using sensors with very low pulses-per-mm values.



  • I'll try to get a test print done following your suggestion within the next few days.

    Does it matter which of your proposed values I chose for testing?
    Does either value have some clear advantages in testing over the other?



  • Same test print as before, just with an E value of 100 in M591.

    Result:

    M591 D0
    Pulse-type filament monitor on endstop input 3, disabled, sensitivity 5.00mm/pulse, allowed movement 50% to 150%, check every 100.0mm, current position 0.0, no calibration data
    

  • administrators

    Can you use a multimeter to measure the voltage between the two outside pins of the endstop input connector you are using for the filament sensor, with the sensor wheel in positions that do and don't illuminate the endstop LED?



  • Did the measurement.

    Had a "magic moment" when trying the first measurement, as I must have shorted E0 signal pin and one of the erase jumper pins during a print. Print came to stop, web interface was not reachable - I thought I fried the Duet. But it did respond to bossac, so in no time I was gladly running again 😉

    As far as I can tell you the sensor outputs signal HIGH and signal LOW each for half a revolution of the sensor wheels - if this is of any relevance.

    HIGH signal level is a stable 3.11V, LOW signal level is stable at 0.81V.



  • .... just a gentle bump to this topic ... 😉



  • @dc42 I don't want to bug you, but rather have you just not forget about this topic 😉
    Many thanks in advance, David!


  • administrators

    It's on my list, but it's unlikely that I will have time to look into it this year. I have a huge amount of development work on my plate right now.



  • Thanks for the quick response!

    I understand that there are plenty of other things to be done first - I just wanted to be sure you noticed the voltage levels measurement you requested.

    Thanks again!


 

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