PINDA and GND & VSSA on toolboard
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I'm planning on using a Prusa PINDA on a toolboard 1LC as a Z bed sensor.
The Pinda has four wires - GND and +5V, signal, and a thermistor out, the thermistor seems to be connected between GND and the the output cable, and is intended to temperature compensate the sensor.
On the toolboard, the temperature connections have VSSA, distinct from GND on the IO connectors. Is connecting a thermistor to temp1, the other side of which is to GND on IO2 rather than to VSSA a really bad idea?
It seems to me the options are:
1: that it will all be fine (because VSSA and GND are, in practice, close enough); or
2: it will do something bad to something (though I'm not sure what that would be); or
3: it won't do any harm but it won't do any good (eg if VSSA and GND are too different for the thermistor output to be meaningful). -
undefined Phaedrux marked this topic as a question
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Since no-one has responded to this, I've just tried it and it works fine. My testing is basically just to compare it to what the tool (i.e. nozzle) reports when the printer has been sitting idle for some time. That means the testing is only over a few degrees (my room temperature doesn't vary that much), but over that range the nozzle and the PINDA agree what the temperature is.
More interesting is I've tried some calibration of the PINDA trigger height against temperature, but I'll write that up in a separate post.
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undefined achrn has marked this topic as solved
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@achrn I'm glad it's working for you. If the thermistor in the PINDA is a 100K thermistor, then at the range of temperatures that the probe is likely to experience, the difference between VSSA and GND wont make much difference. There would be a greater error at higher temperatures.
