Disabling pins on Teensy LC

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JarkkoL

JarkkoL

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Hi,

I have a situation where I need to solder a 4 pin connector to back of Teensy LC: pin 12, pin 17, 3.3V and GND. However, I need either of the output pins to support PWM, so I though of connecting Pin 20 to Pin 17. Is there a way to disable a pin, i.e. I would like Pin 17 to "hang in air"?

Thanks, Jarkko
 
I'm trying to understand your question. Maybe you're talking of pin 17 which is between 3.3V and pin 12. Or maybe the one between 16 and 18?

Or maybe you mean both, one in the first sentence and the other later in your message?

Pin 17 already supports PWM, so I also don't understand why you'd want to connect it to pin 20.

Maybe I just misunderstood? I can't quite grasp what you're asking or exactly what you're trying to accomplish.
 
Oh right, I mean Pin 17 between Pin 12 and 3.3V. I didn't realize it's the same pin as pin between 16 and 18 (but at Vin voltage). I thought the pin 17 between pin 12 and 3.3V didn't support PWM, so I wanted to connect Pin 20 to Pin 17, because my connector is soldered to these 4 pins at the back of Teensy. Just out of curiosity if I would like to do this, is there way to set some PinMode() that the pin "hangs in the air"?
 
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If what you are asking is 'I want to solder to pin 17, but not draw any current from whatever is connected' then think the correct wording is 'how can I get the highest impedance on a pin'.

Simple answer is to leave it be, since that will leave it disabled unless you specifically do something otherwise with it, unless the LC has any higher impedance pin states in it's power saving options. Arduino in assorted flavours are different, so do be careful if moving to another micro exactly what state things initiate to.

What this won't do is disable the protection circuits so you still can't drop it below 0 or above 3.3V without things getting untidy.
 
Thanks for clarifying the terminology GremlingWrangler. Yes indeed I was referring to a high impedance / floating pin. I have to do some adhoc soldering on my prototype circuit to add a connector to it thus the question. But luckily Pin 17 has PWM support like Paul mentioned and it should be quite easy to reconnect my current connected Pin 17 (between 16 and 18) to 18, which by chance happens to be free, phew :)
 
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