sudomod

After reading several threads about safe / soft shutdown solutions, I saw that many people were having problems with the price or availability of components. I designed a different solution that uses very common/cheep components to do the soft shutdown.

Parts List:
DPDT Switch - which you probably already have
Diode (LED can also be used for Pi Power Status Light)
110K Ohm Resister (Optional for 1 second delay)
10Uf Capacator (Optional for 1 second delay)


https://easyeda.com/jonathandavidulrich ... 7418fd4681

Bench testing has been good. Ill be implementing this over the weekend and will update on how well it works out.

Could be very handy for some people. I would definitely step down to 3.3V if the output from the power boost is 5V. Better safe than sorry, and is very easy to do with a simple voltage divider.

Is the GPIO15 output a part of the UART? I know many say that these stay high until the Pi is almost completely powered off, but I actually was never able confirm this when I tested it.

codeman0624 wrote: ↑

Fri Sep 08, 2017 1:45 pm

Could be very handy for some people. I would definitely step down to 3.3V if the output from the power boost is 5V. Better safe than sorry, and is very easy to do with a simple voltage divider.

Is the GPIO15 output a part of the UART? I know many say that these stay high until the Pi is almost completely powered off, but I actually was never able confirm this when I tested it.

Yes, GPIO15 is also UART RXD. I pulled the idea from another post that was using the UART as a keep alive. The problem I am trying to solve is some other solutions were connecting the stepped down VSH signal from the powerboost to shutdown the pi, but that would drain the battery while it is turned "off". Others tried to fix that with a JFET, but i didn't have any on hand, and i am a do it now with what i have kind of guy