Modules are not autoloading with power plug, while USB cabble connected

Started by user330, September 01, 2020, 05:56:50 PM

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user330


Hello to all!

I was faced with the impossibility of autoloading the modules when power is supplied to the camera while the USB cable is connected to it.

So I have a Canon 650D, firmware 1.04
I use
magiclantern-Nightly.2018Jul03.650D104.zip
OR
magiclantern-crop_rec_4k.2018Jul22.650D104.zip
it doesn't matter, the behavior is the same.

So, the initial state of the experiment:
650D is on, ML is loaded, modules are loaded, the option to autoload modules on failure is ENABLED, and the display console is ENABLED when loading modules.
A mini-USB is connected to the 650D, which is plugged into the turned on Raspberry Pi (no software in the RPi tries to use the camera in any way. But I must say that the negative power supply for the RPi and 650D is common, + the power supply RPi = 5V, + the power supply 650D = 8.4 v)
Instead of a battery, the 650D is powered by a homemade battery adapter with a wire (dummy baterry).
Switch on the camera to ON


Experiment start:
- I reboot the 650D by opening the SD card cover - everything is ok, ML is loaded, the modules are auto-loaded.
- I reboot the 650D by opening the battery compartment cover - everything is ok, ML is loaded, the modules are auto-loaded.
- I reboot the 650D by completely disconnecting the main power supply from the camera (pulled out the wire) - NOT ok, ML has loaded, the modules have NOT auto-loaded.

I take out the USB wire:
- I reboot the 650D by opening the SD card cover - everything is ok, ML is loaded, the modules are auto-loaded.
- I reboot the 650D by opening the battery compartment cover - everything is ok, ML is loaded, the modules are auto-loaded.
- I reboot the 650D by completely disconnecting the main power supply from the camera (pulled out the wire) - ok, ML has loaded, the modules have auto-loaded.

I insert the USB wire again:
- I reboot the 650D by opening the SD card cover - everything is ok, ML is loaded, the modules are auto-loaded.
- I reboot the 650D by opening the battery compartment cover - everything is ok, ML is loaded, the modules are auto-loaded.
- I reboot the 650D by completely disconnecting the main power supply from the camera (pulled out the wire) - NOT ok, ML has loaded, the modules have NOT auto-loaded.


Does anyone know how to get ML to autoload modules when the USB cable is connected after power up (without opening the SD card or battery compartment covers)?
I honestly tried to find a solution to the problem on the forum, but did not find it.
I can fix this with a hardware mod, but I would like to solve the problem more gracefully.
Thank you for your help!


Walter Schulz


Walter Schulz

Confirmed for 650D.

Unable to test with my 7D (Digic 4) because of its faulty USB connector.

If someone wants to test it without external power supply:
Open battery door and actuate its switch. If you are able to remove the battery without losing contact you are able to reproduce OP's setup. Would be interested if D4 cams act the same way.

user330

Walter Schulz, thanks for the independent testing and confirmation!

Some additional news:
Today i have eliminated RPi from the equation (and accordingly, the influence of DATA lines of USB).
Now, I just supplied power from a simply mobile phone charger (5v independent) via miniUSB to the camera's usb port.
And the behavior is exactly the same.
It looks like when the usb hub chip in the camera is powered, then the problem appears.

Walter Schulz

I used USB connected to PC, EOS Webcam Utility + OBS.

This is a bug for sure.

user330

Should we report this somewhere? (unfortunately, iam not strong in the culture of collective software development and have no idea how to proceed)

I just think that the mechanism for loading modules is very important, some of the most delicious ML features are implemented through it (like a silent shoot, for example)

This should have been encountered earlier, because when controlling the camera remotely through usb (for example, via gphoto2), users often use plugins (astrophotographers, timelaps creators).
Also, sometimes the camera requires a remote reboot (when it freezes, or then "Replace battery" error for example) and the easiest way to do a remote reboot without hardware modification of the camera is to turn off the power via the dummy battery.

But in this case, as we can see, the camera does not load plugins after rebooting.
Someone must have stumbled over this! (like me with my telescope) There should be a lot of us like that!

Senior comrades, tell me what to do next?


user330

Walter Schulz, first of all, thank you for you bug report! Hope this helps fix it someday!

While there is no software solution, I solved the problem with hardware using HIGH SIDE POWER MOSFET SWITCH IPS521G.

On a signal from the RPI GPIO port, it turns on or off the output power (+ 5V) on the USB cable (before remote reboot i turn-off usb power and after boot up camera i turn-on usb power).

I drew the simplest diagram, I hope someone will work well. Maybe later I'll shoot a video that the circuit works.