I built AR4. I use software and sketch version 3.0. When I try to check all joints and try to auto calibrate, joints don't stop when they reach to limit switch. They keep moving until they break down limit switches. But calibration works when I try to calibrate only one joint.
Why they don't stop?
I found the problem. It's simple. The problem is because of GND. Because GND signal doesn't reach the limit switches, this error appears.
When you run the limit switch test program do you see all the switches showing 0 or 1 or do they change between those states with nothing moving?
do you still get 3.3V on your teensy board? if not then your board is damaged
You will need to check each limit switch and make sure it is returning 0 volts or ground to the Teensy board when the switch is not made and then returns 3.3 when the switch is made. The board inputs are very susceptible to floating voltage so it's important that when the switch is not made that each input pin is getting a solid ground signal.