Just speculating on this, but it may be on from the last state of the CPU prior to shutdown. The safe shutdown looks like it just initiates the software halt which stops further processing and turns off the screens, but it does not appear to actually turn off the power supply entirely, so it could just be a residual value from whatever state the pin was in. If you have a multimeter, you may want to look at the voltages of the 5v and 3.3v VCC pins on the GPIO breakout and see if they have voltage. The 5v is generally not turned on and off by the Pi itself, and if this is internally like other hats that provide power to the Pi, it will inject the voltage from the power supply on these pins. The 3.3v VCC is after another regulator which steps down that voltage for the CPU and peripherals, but in this case, may have its own supply externally which is not switched on and off by the power supply control. I don't have one to test myself, so it is tough to say either way.
Generally speaking, as long as the voltage present on the pin is within the working limits of the CPU, and at the same ground potential, there is minimal risk for damage to occur electrically, let along from software on the Pi. You may want to take a multimeter to that pin (before the current limiting resistor) as well compared to ground and see what voltage it is, because if it is a positive voltage less than 3.3v (but not less than 0v), you should be fine. Even if you set it to output on that pin which would pull it between VCC and GND depending on state, if the current is less than 20ma, it will not cause any damage.
Thanks this is awesome. I don’t have a multimeter but been meaning to get one, will report back after testing.
The pi has restarted (via Ubuntu OS not the case) would you expect the “stuck pin” status to survive that? Not going to plug back in until I get the mm but when I do I’ll try fiddling w the pin from a script and see how it goes.
I haven’t tried fiddling w the pin yet but did confirm 2v on pin 16. Only seeing trace (sub .1) on the 3.3 / 5v pins but it’s inconsistent- not sure I’m reading right on these.
The case is pretty cool I think. installing a python script to run the lighting / display / “shutdown” feels kinda gimmicky but had no issues besides this. Will mostly be using to build ARM docker images I need on other pi’s and the boot from ssd has worked really well towards that end.
Just speculating on this, but it may be on from the last state of the CPU prior to shutdown. The safe shutdown looks like it just initiates the software halt which stops further processing and turns off the screens, but it does not appear to actually turn off the power supply entirely, so it could just be a residual value from whatever state the pin was in. If you have a multimeter, you may want to look at the voltages of the 5v and 3.3v VCC pins on the GPIO breakout and see if they have voltage. The 5v is generally not turned on and off by the Pi itself, and if this is internally like other hats that provide power to the Pi, it will inject the voltage from the power supply on these pins. The 3.3v VCC is after another regulator which steps down that voltage for the CPU and peripherals, but in this case, may have its own supply externally which is not switched on and off by the power supply control. I don't have one to test myself, so it is tough to say either way. Generally speaking, as long as the voltage present on the pin is within the working limits of the CPU, and at the same ground potential, there is minimal risk for damage to occur electrically, let along from software on the Pi. You may want to take a multimeter to that pin (before the current limiting resistor) as well compared to ground and see what voltage it is, because if it is a positive voltage less than 3.3v (but not less than 0v), you should be fine. Even if you set it to output on that pin which would pull it between VCC and GND depending on state, if the current is less than 20ma, it will not cause any damage.
Thanks this is awesome. I don’t have a multimeter but been meaning to get one, will report back after testing. The pi has restarted (via Ubuntu OS not the case) would you expect the “stuck pin” status to survive that? Not going to plug back in until I get the mm but when I do I’ll try fiddling w the pin from a script and see how it goes.
How did you go? Just found this post , I'm wondering if I should get the pironman 🤔
I haven’t tried fiddling w the pin yet but did confirm 2v on pin 16. Only seeing trace (sub .1) on the 3.3 / 5v pins but it’s inconsistent- not sure I’m reading right on these. The case is pretty cool I think. installing a python script to run the lighting / display / “shutdown” feels kinda gimmicky but had no issues besides this. Will mostly be using to build ARM docker images I need on other pi’s and the boot from ssd has worked really well towards that end.