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bdring / 4_Axis_External_Driver

A Grbl_ESP32 Controller for External Stepper Drivers
MIT License
19 stars 3 forks source link

No Pullup Resistor for the Probe #4

Open nsiatras opened 3 years ago

nsiatras commented 3 years ago

First of all I have to say that you have a very nice board here.

I noticed that you do not have a pullup resistor for the probe input but you have pullup resistors for the X,Y,Z and A limit pins. Why you didn't add a pullup resistor for the probe too ?

Cheers

bdring commented 3 years ago

The probe is on a pin that has an optional internal, to the ESP32, pullup resistor. The ESP32 has that feature on most pins, but not the XYZ pins.

In hindsight, I probably should have put external pullups on all inputs. The Internal pullups are rather weak (40k-60k ish). I lower value of 5k-10k would help against noise.