Disconnect Pin in Software

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tgangemi

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Is there any way to have a pin disconnected via software?

I've built a PCB for a LED strip project but realised I may need to use a serial port pin for the strip's data signal due to interrupt issues. If I simply add a jumper wire from the new pin over to the old, is there a way (via software) to stop the original pin interfering with the signal? Ultimately, I could probably just cut out the original pin's connector but I'm just trying a less destructive approach first.

Thanks!
 
Possible. Depends a little from which pin. The chapter 10 of the Teensy 3.2 and 3.5 processor reference manuals and chapter 11 for the T 3.6 explains the pin signal multiplexing and gives hints on how to set the corresponding pin multiplexer register to the Alt0 function which in most cases is a passive high-z mode.
 
That’s probably a right answer but the OP wouldn’t learn as much from that as if he had studied the reference manual...
 
That’s probably a right answer but the OP wouldn’t learn as much from that as if he had studied the reference manual...

Quite right on learning … though so many manuals I find it easier to read the forum and the code. _DISABLE probably isn't in the manual but something PJRC codified to restore the power up 'passive high-z' state.

For inquiring minds look at :: ...\hardware\teensy\avr\cores\teensy3\pins_teensy.c for void pinMode(uint8_t pin, uint8_t mode) where this happens:
Code:
else { // INPUT_DISABLE
			*config = 0;
		}
 
Thanks for the answers, I appreciate the help.

Even I agree on the learning - Having an answer with an explanation is always preferred as the problem is often not knowing where to start looking. In this case, I wasn't sure if it was a question primarly about Teensy, MCUs or basic electronics.
 
why would you jump a wire? some pins have multiple capabilities, like using the same pin for the led strip and serial
by changing it’s MUX config
 
ahh ok reread custom pcb with bad pin location, makes sense
by default all pins are in a low power disabled state (hi-z) so don’t need to configure the “dummy pin”. just a wire jumper should do it and run library as normal
 
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