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General Mach Discussion / Input pin help
« on: April 12, 2013, 09:52:26 AM »
I am shortly about the make a touch plate for auto z function so I thought I'd check things out with my mach set up.
On ports and pins/inputs I have 4 of the 5 input pins used 3 home switches and an estop. This leaves me pin 13 to use.
A quick check down at my breakout board shows 5v end shows 5v already on the pin. I'm guessing the port itself has pull up resistors at the computer end. So I set pin13 as the probe pin, enable it, set active low, apply the settings and clear the estop trigger and the green digitise led illuminates on the diagnostics page.
All good so far. Now I then ground p13 but led stays illuminated. The ground I use is common with the port ground. I've tried grounding through a resistor everything but nothing happens. I've tried it with putting a separate 5v on the pin via a pull up resistor before I realised it already had 5v on it.
Has anyone got any ideas?
On ports and pins/inputs I have 4 of the 5 input pins used 3 home switches and an estop. This leaves me pin 13 to use.
A quick check down at my breakout board shows 5v end shows 5v already on the pin. I'm guessing the port itself has pull up resistors at the computer end. So I set pin13 as the probe pin, enable it, set active low, apply the settings and clear the estop trigger and the green digitise led illuminates on the diagnostics page.
All good so far. Now I then ground p13 but led stays illuminated. The ground I use is common with the port ground. I've tried grounding through a resistor everything but nothing happens. I've tried it with putting a separate 5v on the pin via a pull up resistor before I realised it already had 5v on it.
Has anyone got any ideas?