I have a NPi i.MX6ULL Dev Board - Linux SBC - eMMC board and want to set it to automatic power ON when power plugged in mode. (without pushing the Power button)
How can I do this?
This is the default state as your describe(without pushing the Power button). can you make video to show me abnormality ？
That’s True, but previous state was turn off (by pressing Power button or automatic power off when temperature exceed than critical point) when power plugged the system not turn on. Actually, when power plugged the system keep the last state.
I want when power plugged, regardless of the last state, always turn on (without pushing the Power button). How can I do this?
Have you ever tried re-flash images?
Yes. I used internal eMMC and “imx6ull-debian-buster-console-armhf-latest-2gb.img.xz” image file.
May I chip in here as I have some insight into this problem. I have a similar problem that I have made a UPS hat for the board and once the board is powered off it will not turn on again without pressing the ON/OFF button. The application in my case is that the board is to be used in a remote location so pressing the button is not an option. The UPS is designed to provide power for the short amount of time to power the board down safely without corrupting flash memory. On all the Seeed boards supplied to me so far the button battery on the board has been flat. When the battery is flat once the board is powered down then it can be started again when the power is reapplied. However, if the battery is good then the board will not power up again. I think this is because when the battery is good then the ONOFF signal is kept high by the IMX6 itself from the button battery supply. Since the ONOFF signal never goes low the IMX6 does not power up. What I have noticed is I can power the board down using “sudo poweroff” and then it will not reboot when power is reapplied. However, if I don’t use “sudo poweroff” and just cut the power the board will power up. Therefore there is something in the poweroff sequence that makes it so the board has to see a button press before it will power up again. Before you ask I have downloaded the latest firmware to the board.
I’m not sure what you are doing. How do you use the UPS?
The primary power source may fail and therefore the UPS in our case is being used to provide power when the primary power source fails. The UPS board also provides a signal that indicates that the primary power source has failed. This signal will be monitored and when the primary power is detected as failed the IMX6 board will then be poweroffed safely using ‘sudo poweroff’. The UPS board has an enable line that enables the secondary power source and when this goes low or high impedance the power will be disconnected. The UPS is not designed to provide power for long periods of time but is designed to provide power while the board shuts down cleanly so that the filesystems are not damaged. So the problem comes when the primary power is reapplied. When the primary power source is reapplied power is automatically provided to the IMX6 board but the IMX6 board will not boot. It will only boot when the ON/OFF button is pressed.
This is quite easy to check yourself. All you need to do is use the ‘sudo poweroff’ command. Then once the board has powered down turn off the power supply to the board for a while. Then turn the power supply back on and the board will not boot. Now press the ON/OFF button for a bit and the board will boot normally. As mentioned before though the functionality is different if the button battery is dead, so first check that the button battery is working by measuring the voltage across it. It should be around 3.0V. If the button battery is dead then the board will boot when power is reapplied. We want the button battery working though as we want the real time clock functionality.