I am using a smoothie V1 to run the motors on a pick and place I built to pre-program Micro-controllers. It has been running great now for almost half a year. One day it started to a do thing when it homed the z axis it acted like the endstop stopped working because it would move up and just stall out. So I brought up the serial console and started playing around sending m119s, and sure enough Z min was a zero. I then verified all the other endstops by moving the gantry, and they reported properly, all of the sudden the Z stop reports properly. It will usually continue to work properly, and can be homed and run the machine, until I reset the board.
The first thing I tried was to put a multi meter on the headers giving the signal to the smoothie board, and that part was working properly. I then tried to update the firmware and start with a fresh config file, still nothing. I also blew out the board with compressed air, there was only a lit bit of dust on it that flew out.
I’m guessing the cortex on the board is flaking out? I cant find anyone else online that had this strange behaviour. I am tempted to just try hot air a new cortex chip on. Anyone have any ideas? Thanks in advance.
if you are sure it is onboard and not wiring, trace the endstop signal and retouch components with a soldering iron in case there’s a fractured joint. Look at the ground pin or just retouch the solder joint there too. Trace the Sig path all the way to the MPU.
then I’d try putting a 4.7K or 10K pullup on the Sig line.
what endstops do you have? Endstops are recommended to be set for NC(normally closed(grounded)) and when triggered opened(sig goes high). So a pull-down would indicate something different since you wouldn’t expect there being any problem pulling a signal via a switch to ground.
The NC preference is because it means that an open/broken wire will open the endstop and stop the machine as opposed to the machine going to the endstop during a homing move and grind out a belt or break the machine with no endstop trigger sensed.
Basically, the head of the machine, along with the head board pcb is off of a quad 4c pick and place machine that we scrapped years ago. Which used optical sensors that source voltage. I didn’t change any of the sensors because it was such a nice package.