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I've been trying to use a CM5 on the PiGear Nano - I can flash the OS to eMMC and it boots OK, but only if I bypass the power switch. If the power switch is not bypassed then the board turns off after a couple of seconds.
Are there any details available on the power switch circuitry to help me debug it? One of the changes from CM4 to CM5 is around the RUN_PG pin (replaced with PWR_Button) so I'm wondering if that might be an issue, if you use RUN_PG to keep the power latched on.
I've poked around in the pgnano code looking for clues, but I didn't see anything that seemed related to the power switch.
Posted : 13/03/2025 4:25 pm
it boots OK
I am kind of surprised: as far as I know, PiGear Nano can not boot CM5 because CM5's buit-in PCIE conflicts with VL805 on PiGear Nano.
Posted : 13/03/2025 4:37 pm
Topic starter
What kind of conflict? It boots to desktop OK, and didn’t seem to be complaining about anything.
Any thoughts on the power switch?
Posted : 13/03/2025 5:24 pm
Any thoughts on the power switch?
The power switch circuit on PiGear Nano is similar to this one: http://www.mosaic-industries.com/embedded-systems/microcontroller-projects/raspberry-pi/on-off-power-controller
With additonal circuit that can automatically "long press" the button to force power cut when TXD goes low.
Also PiGear Nano uses GPIO26 instead of GPIO4 for button.
If the power gets cut after a few seconds, maybe TXD(GPIO14) or GPIO26 gets pulled down during the boot.
Posted : 14/03/2025 9:09 am
usedbytes reacted