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.
@orcun-oruc-aykac 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.
@chris-annin When the switch is made 1.03 volt returns, but when its not made then returns 0. I didn't understand why returns1.03 despite 3.3v. 🙄
@orcun-oruc-aykac What voltage do you get at the 3.3 volt terminal on your Teensy board when you measure between the Ground Terminal and the 3.3 volt terminal directly at the board?
Normally 3.30V. But when I reboot teensy board by clicking teensy.exe it returns 3.29V.
BTW, this the limit switch I use.
Additionally, there isn't any voltage at the limit switches when the motors not powered. There is voltage (but not 3.3v) only when the motors enabled.
https://anninrobotics.com/wp-content/uploads/2025/08/Auto-Calibrate-doesnt-work-properly-.avif
And see limit switches testing. I pushed J1 button of limit switch. it turns 1 and then 0 and repeats like that. Something is wrong. I think the fail is at voltage or GND.
https://anninrobotics.com/wp-content/uploads/2025/08/Auto-Calibrate-doesnt-work-properly-_2.mp4
When I measure voltage at the brown and brown with white strip color in the box behind robot, which the cables and motors are connected inner, voltage is 4.06. (I think it should be 3.30v) I tried to unplug GND (brown with white) from teensy board than voltage is 0.96v. It should have been 0, shouldn't it?
do you still get 3.3V on your teensy board? if not then your board is damaged
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?
