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I'm currently suffering from issues where my raspberry pi appears to lose power over time and shut down (I'm using a pico UPS to handle file safe Shutdown). From the symptoms i'm seeing it appears like there's still power to the system (e.g. the red LED is still on when I come back to the raspberry pi after it loses power). I haven't tried shorting pin 5 and 6 together after power loss to see if it can actually boots, but pulling the power out and plugging back in boots the pi as normal.

I need my system to stay up without human intervention however.

A quick look at the logs looks like the file safe shutdown is being generated by the UPS, however I've not been able to determine what's causing the power loss.

My project involves a simple header for a raspberry pi that converts UART to RS232 and multiplexes to one of eight RJ45 ports.

enter image description here

Each port uses the eight pins for the following:

  • pin 1: RS232 tx
  • pin 2: 3.3 V or GND sourced from rpi for binary addressing pins on 1-wire thermocouple
  • pin 3: 3.3 V sourced from device on the other side of the RJ45 to give 'connection sensing'
  • pin 4: 3.3 V or GND sourced from rpi for binary addressing pins on 1-wire thermocouple
  • pin 5: connected GNDs from rpi and end device
  • pin 6: 3.3 V or GND sourced from rpi for binary addressing pins on 1-wire thermocouple
  • pin 7: 1-wire thermocouple data bus
  • pin 8: RS232 rx

Could the power loss i'm seeing be caused by something i'm doing in my circuit? Or is there a well known issue with pico ups' that causes this behaviour (I've searched a lot but been unable to find anything).

Is there perhaps a way for me to ensure the system is always on? E.g. if it detects that it has shutoff, to keep trying to turn back on until it boots.

Thanks

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    \$\begingroup\$ Please provide a data sheet link to "pico UPS" and state what "FSSD" means. \$\endgroup\$ – Andy aka Mar 17 at 8:51
  • \$\begingroup\$ @Andyaka My apologies, I've added that in to my original post. \$\endgroup\$ – Cinfra Mar 17 at 9:05

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