Can you give us more details about what you’re trying to use with port 3? What sensor are you using? Are you plugged in to the analog or digital side? If you could post your code, that would be great as well.
It sounds like you are trying to read a digital port that is set for output (or write to an input), make sure the controller configuration is setup correctly. The default for the cortex is digital ports 1 to 8 as input, 9 to 12 as output.
Just so you know, it happens even if I pull EVERYTHING out of the A/D ports. Maybe something in the code? Or my computer? I just don’t know. I swapped many items already to try and isolate the cause. The first thing I pulled out was all inputs into the cortex (Joystick, Cortex).
I downloaded new code. Wrote a quick program. Changed batteries (ALL OF THEM).
Next step was to change computers that I am using.
I won’t be able to do any more testing until boys come home after school. Nothing special in the code so I am posting it. Any ideas would be appreciated.
Recheck all the ports you are using, this is where code full of “magic numbers” hurts you, the best approach is to define constants once in the code and then refer to everything by name rather than number.
Happy to help, it’s not “wasting” my time and I’m sorry if the tone of my post implied that. I don’t think you need to start from scratch, these were the only instances I found and it was simple just to use “find” to search for these (search on things like GetDigitalInput). Define the ports you are using (for example, #define ARM_SENSOR_FLOOR 5 ) and then if the robot needs rewiring for whatever reason there is just one place in the code that needs to be changed.
Oops - I didn’t mean to imply anything other than our own stupidity. I am the one that feels I wasted your time on our stupid mistakes. Trust me - I read lots of posts here on this forum and we are all better off for having someone like you here to help.
Sincerely, thanks for all that you do here at the VEX Forum.