Hello folks,

i have an question about pin SCL, and SDA for use,

on this moment i was using the SCL pin and GND to get a Auto leveler for my CNC using BCNC software and Grbl, i use SCL with normal closed

look like this image

but now i have made another Probe to Automatic Zero my tool change Look like this


but my question is, i can use the SDA for the seccond probe signal ? if yes i need edit some thing on bcnc or on GRBL, and where i can find if the pins SCL or sda is normal open or closed.

i dont find nothining about this question on forum, thx so much if u can help me with this, i guess is the question of some folks also.

Look into the Arduino Pin Mapping of your board to find out which analog or digital pins hide behind the SCL and SDA labels.

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Don't use SCL and SDA in your code, on the Uno use A4 and A5 instead. These pins can be used as anlog or digital pins. For digital I/O use pinMode() to configure the pins as for any other I/O pins.

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Right, but grbl uses A5 (or pin 19) for the probe by default. That is a grbl thing. When you issue a probe command, grbl watches for A5 (in digital mode) to change state.

I have not seen any way to add a second probe to grbl.

You can change the probe pin in cpu_map.h. But that means that you re-compile and upload the grbl code.

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Thx so much for all this answear, i guess the fastest way is link my both probes on series, normal closed, i dont go use both at same time, but if i want use one of them i dont need replug anything,

thx so much folks for try sove my problem, sirs you are a hero, thx, have a nice day !

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