Wiring filament sensor to SmoothieBoard

[Mark Rehorst]

I have designed a filament-out sensor and will be connecting it to the SmoothieBoard in my printer.  I plan to use the P1.30^, P1.31^, and gnd pins for the input connecting to a SPDT microswitch, with the switch's NO contact connected to pin 1.31^.  If I understand correctly, when filament is present, the NO contact will be closed, pulling 1.31^ low.  That will allow the printer to run normally (at least that's what I want it to do...).  When filament breaks or runs out, the switch will toggle and the NO contact will open and the NC contact (at pin 1.30^ will close) causing the machine to pause, per the example in the switch configuration page. When new filament is put through the sensor and into the extruder, the printer can resume printing. 

Two questions: 

Do I need to do anything to protect the input pins (add some series resistors)?

Will it work the way I'm thinking, or will the closed contact at 1.31^ at the start of a print cause weird behavior?

Here's the sensor:

[wolfmanjm]

why do you need two input pins? one should be sufficient?

[wolfmanjm]

I also think you should probably use the filament detector module. The main advantage is it only checks the sensor when it is extruding, this stops false triggers.

[Mark Rehorst]

Good idea!  I was going to use the second contact to restart the print when fresh filament is inserted into the detector, but maybe there's a little too much additional prep to do after loading new filament before the print can be restarted- priming the extruder, etc.

[flapjack]

Hi, I am trying to do the same thing with optical sensor. However, it does not pause at all. Led on the sensor indicates it is working. What should I look at?

2 Aralık 2016 Cuma 09:05:13 UTC+3 tarihinde Mark Rehorst yazdı: