[Project Demo] - Pi-Top 4 DSLR camera wireless control

[Luis]

Hi All,

Thought I share a quick demo with everyone of the DSLR wireless remote control. This is especially useful for cameras that do not have integrated wireless capabilities.
What it does?
It basically allows you to control the camera remotely from your phone. Almost all camera parameters can be adjusted from the phone app.

https://youtu.be/M_spP2K9iy0

As seen in the video the DSLR camera is connected to the Pi-Top via USB cable. There is a script that is running a mini-server, the phone app is the client of this mini-server.

For this to work you need to kill process gphoto2 once the camera is connected to the Pi-Top otherwise this will not work (at least this is what I noticed from my testing).

In case anyone is interested to try this out, below you will find the git repository:
https://github.com/hubaiz/DslrDashboardServer

And a link with the supported cameras
http://www.gphoto.org/proj/libgphoto2/support.php

Next steps would be to integrate a stepper motor and make use of the extra ports from the Universal PCB to control the stepper motor for an automated focus stacking rail. Maybe this would be even easier with the help of the pitop robotics kit. Not sure how powerful are the two motors but I see that the expansion plate has 12V ports for motors.

Have a nice weekend everyone,
Luis

[CAProjects]

Focus ring motors, external ones are not all powerful as it is, the robotics kit motors should be fine

[elipitop]

This is brilliant. Can’t wait to try it. I have an older DLSR that I have been annoyed with on several occasions due to the lack of a remote.

[Luis]

@elipitop: If you need this in a smaller size, prior to having the pi-top, I implemented this on the pi-zero:
https://www.instagram.com/p/CCRJCMTBN6d/?igshid=pemmgzvj5nj9
Would be great if we had a pi-top variant for the pi zero wireless😁.

[duwudi]

@Luis this is super cool, nice one! I think we’ve got your Sessions project for this month sorted

@Luis

Not sure how powerful are the two motors but I see that the expansion plate has 12V ports for motors.

The expansion plate only supports encoder motors but there is a stable 12V available there that can be PWM’d through H-Bridges - I’m sure you could figure out a way to get a stepper motor attached. I’ve attached pumps and solenoid valves before for projects involving water and it worked well.

[Luis]

@duwudi: Thanks a lot😁, I’ll have to do a bit of research on the macro rail and the use of stepper motors for the focus stacking script. I don’t have a macro rail or the expansion plate at the moment.
How powerful (torque) are the encoder motors from the robotics kit? Would you happen to know if the two encoder motors can push-pull around 4kg of equipment without any special gearing? Thanks

[duwudi]

Peak torque is 0.43Nm I believe, you’d have to do the calculations to see if that’s enough for 4kg as it depends on a number of factors

[Supernovali]

Haha, TLDR; those are somewhat beefy motors, I don’t think you’ll have a problem turning a focus ring.

.43 Nm?!? Dang… As far as the calculations go, here is your formula:

f=T/L

Where:
f = Force (in “N” newtons),
T = Torque (in “Nm” newton-meters)
L = lever-arm Length (in “m” meters)

You’ll need some experimental data to calculate, but, since peak torque is .43 Nm, I’d say you have plenty of torque for the focus ring.

Here is a calculation on the amount of force the robotics kit can deliver from the drive wheels in “ideal” conditions:

0.43Nm Torque / .037m lever-arm = 11.621N of Force.

Since 1 Newton is the force required to accelerate 1kg of matter to 1m/s², and gravity’s acceleration is 9.8m/s², the motor would be able to support the following weight in a stalled condition (granted peak torque occurs at the stalled condition, ie rpm = 0):

f=ma (force equals mass • acceleration)

Mass = 11.621N / 9.8m/s²
Mass = 1.186kg

If you were to secure a hand-held scale and rotate the focus ring about it axis at the edge, I don’t think most focus shutters would require that much force.

Also, consider that if you build a robot with an all up mass of 1.186kg, then that same robot would accelerate at 1G at its peak torque point, minus friction and drag.

What that looks like? After 1 second, the robot would be over 4 meters away! After 2 seconds, it would be over 14 meters away! Take it with a grain of salt. The motor is going to have a maximum speed and won’t produce peak torque except at a specific rpm. Kind of makes me wonder what these motors torque curve is.

[Supernovali]

Just saw this…

You would probably need to use gears if you plan on having a vertical axis. I’m not sure what you plan on using the macro rail for but I’d you only plan to have an axis perpendicular to the gravity vector, it should be just fine.

[Luis]

The plan would be to use the motors for the macro rail, not for the focus ring as the focus will be handled by the swm motors in the lens.
One motor would need to go at the end instead of doing this manually and controled via software for precision focus stacking. The whole camera rig with flashes and everything is about 4kgs max. The speed here is not very important as you would want maximum precision.(i.e move the whole asembly 1mm at a time backwards or foward).
In practice the camera will move forward based on an input value, autofocus, take a shot, then move again, focus, take another shot and so on.
This is the macro rail as an example:

Many thanks,
Luis

[Supernovali]

That should work then. You may even have to reduce power to the motor to get higher precision. A worm gear has a lot of mechanical advantage If your macro rail can support the weight, I think the world is your burrito!

[Luis]

Thanks for looking into this, will wait to save up some before I pull the trigger on the project with the robotics kit and macro rail. Will first want to try this out with the components I already have and see if I can figure out the software side of things as well.

[Supernovali]

DOOOO ITTTT hahaha jkjk, but I’m excited to see where this goes

[Luis]

Hahaha, had to do some work around the apartment and budget is bust , otherwise I would have spammed the buy buttons .

[Supernovali]

I know how you feel. When payday comes around, I have to stay off Amazon for a few days. Still working on putting the company together hehe