Remote power button for Banana Pi M1

[John Felstead]

I want to put a banana Pi M1 plus a 2.5" SATA drive in a plastic box with only the ethernet and USB ports exposed. This means the onboard power button is not accessible to boot the board.

 

Are you able to power on the board using the GPIO pins? If so please could someone advise which pins to connect to?

 

I also aim to put a 5.5 x 2.1mm barrel connection on the box (with a latching press button switch for isolation) for the +5v supply and connect a short micro USB connector from the barrel socket to the board and also attach the SATA power leads directly rather than powering from the board 2 pin connector to take the load off the micro USB input.

[eselarm]

3 hours ago, John Felstead said:

Are you able to power on the board using the GPIO pins? If so please could someone advise which pins to connect to?

If you look at the wiki page you find the typical 26-pin header like for the original RaspberryPi. pins 2 and 4 are tagged 5V and pin 6 is tagged GND. However, in the schematics there is no mentioning of the 26-pin header. There is GND ofcourse and there is ACIN, that is the 'master' 5V you need to apply and is the same as the VBUS of the microUSB power connector.  As there is also the option to connect a LiPo battery (needs soldering), I decided to use the microUSB input for power, I have enough DIY of those connectors (need soldering) as I am not 100% sure if ACIN is exactly the same as pins 2 and 4. I also use a very small DC/DC from 12V to 5V, so I have 12V, 5V, GND for BananaPi and 3.5inch HDD. In never do anything with power button, It is just and old molex connector that I use to connect/disconnect power. You will have the SATA connector sticking out quite a bit, even more then the microUSB for power, so using 26-pin header for power is not getting it much more compact. 

[John Felstead]

thanks @eselarm. I think I may not have made myself clear. I want to be able to "Power On" i.e. boot the board using a remote switch and not Power (provide 5v) to the board via the GPIO pins. The Banana Pi docs here (half way down page to GPIO section) actually states that you cannot use the GPIO pins for injecting power only drawing power for ancillary boards etc. 

When testing the board and setting it up I accidentally touch the SATA case against the GPIO pins and the board started, I'm not sure what pin it was and if it might cause damage long term starting the board this way but I need to know if its possible and which pin(s) i need to short to ground?

As regards SATA drive I'm fixing the 2.5" drive to the lid of the box and using one of these SATA right angle adapters and a  short100mm very flexible SATA cable to connect to the SATA port on the board and the adapter.

when its built I will upload a photo.

In the meantime I need to be able to reboot the board externally when the power has been disrupted. I could unsolder the existing switch but the solder pads look tiny.

[eselarm]

1 hour ago, John Felstead said:

you cannot use the GPIO pins for injecting power

I did not look well enough and also at a local PDF copy of the wiki which I see is more than 2 years old. Same text is there, but not in red at that time. I think I noticed it at the I was soldering the wire, but I clearly forgot the typing the message i this topic. 

Anyway, I have no good idea how to solve your remote power issue. I use a MOSFET that has low Vgs on (works directly on 3.3V , but is not for common GND. Else PoE managed switch where I can toggle power when fatal lockup or so. Or else instruct someone to pull the plug, wait 10 seconds, stick it back in again. If you use CoW filesystems, it is no problem to do this.